Emily's Microbiology Pre-Spring Midterm

Front 1

What is the #1 reason for visiting the doctor?

Back 1

Respiratory infection

Front 2

What is the #2 reason for visiting the doctor?

Back 2

UTI

Front 3

What is the most common nosocomial infection?

Back 3

UTI

Front 4

UTIs occur more often (30:1) in...

Back 4

women

Front 5

UTIs predispose patients to

Back 5

sepsis and shock

Front 6

UTI def'n

Back 6

the microbial invasion of any tissue of the urinary tract, extending from the renal cortex to the urethral meatus

Front 7

How many colonies must be present, per mL of urine, for asymptomatic bacteriuria to be dx?

Back 7

10^5 colonies per mL urine

Front 8

What is asymptomatic bacteriuria?

Back 8

the colonization of the urinary tract in the absence of symptoms, with 10^5 colonies per mL urine, or more

Front 9

What is cystitis?

Back 9

an infection limited to the bladder and lower urinary tract.

Front 10

How does cystitis present?

Back 10

dysuria, frequency and urgency

Front 11

What presents with dysuria, frequency and urgency?

Back 11

Cystitis (limited to bladder and lower urinary tract)

Front 12

What is dysuria?

Back 12

Painful urination

Front 13

What is pyelonephritis?

Back 13

an inflammation and infection of the kidney

Front 14

How does pyelonephritis present?

Back 14

fever, chills, and flank pain, also possibly with symptoms of a lower urinary tract infection.

Front 15

How does urethritis present?

Back 15

pain, burning and discharge from the urethra

Front 16

What is a likely cause of urethritis?

Back 16

STDs

Front 17

What presents as pain, burning and discharge from the urethra?

Back 17

Urethritis

Front 18

What presents as fever, chills and flank pain?

Back 18

Pyelonephritis. Also possibly includes symptoms of a lower urinary tract infection

Front 19

What are the peak times in a woman's life for getting UTIs?

Back 19

Infancy, Preschool, "Honeymoon Cystitis," "Pyelitis of pregnancy," and then continue steady increase into old age

Front 20

When do men tend to get UTIs?

Back 20

Infancy, or elderly years (Prostatitis)

Front 21

Which gender gets more symptomatic UTIs in middle age?

Back 21

Women

Front 22

Which gender gets more symptomatic UTIs in old age?

Back 22

Men

Front 23

Which gender gets more asymptomatic bacteriurias?

Back 23

Women, throughout the lifespan

Front 24

When might men get asymptomatic bacteriurias?

Back 24

Only recorded in old age (>55yo)

Front 25

Which types of bacteria are the most common causes of UTIs?

Back 25

facultative bacteria of fecal origin
E. coli (90% of acute UTIs in normal patients)

Front 26

Most common UTI bacteria in young women that are sexually active

Back 26

E. coli
Staphylococcus saprophyticus

Front 27

Most common UTI bacteria in elderly men with prostate problems

Back 27

Enterococcus faecalis

Front 28

Most common UTI bacteria in young boys

Back 28

Proteus mirabilis

Front 29

Most common UTI bacteria in patients with stones

Back 29

Proteus mirabilis

Front 30

Most common UTI bacteria in diabetics (esp. if poorly controlled)

Back 30

Klebsiella
Group B Strep
Candida

Front 31

Most common UTI bacteria in patients treated with antibiotics

Back 31

Pseudomonas

Front 32

Most common UTI bacteria in patients with underlying disease

Back 32

Staph aureus

Front 33

What % of UTIs are caused by ascending infection?

Back 33

95%

Front 34

What usually precedes an ascending UTI?

Back 34

periurethral or introital colonization

Front 35

What organisms are associated with ascending UTI?

Back 35

E. coli
Other Enterobacteriaceae such as Proteus sp.,
Staphylococcus saprophyticus,
enterococci,
and Candida

Front 36

What % of UTIs are caused by hematogenous route?

Back 36

5%

Front 37

What organisms are associated with the hematogenous UTI?

Back 37

Staphylococcus aureus,
Cryptococcus neoformans,
Coccidioides immitis
and a number of viruses

Front 38

What is the major facultative organism of the urinary tract?

Back 38

E. coli

Front 39

Which of E. coli's virulence factors contributes to its UTI pathogenicity?

Back 39

K1 capsule
• Type 1 (Mannose Sensitive) fimbriae,
• Type 2 (Mannose Resistant) fimbriae,
• Hemolysin,
• Flagella,
• LPS,
• Aerobactin,

Front 40

what property of K1 capsule contributes to its UTI pathogenicity?

Back 40

antiphagocytic

E. coli virulence factor

Front 41

Important UTI-relevant pathogenic feature of type 1 fimbriae

Back 41

Type 1 (Mannose Sensitive) fimbriae enable colonization of the lower urinary tract

Front 42

Important UTI-relevant pathogenic feature of type 2 fimbriae

Back 42

allow colonization of the upper urinary tract.

E. coli virulence factor

Front 43

Important UTI-relevant pathogenic feature of hemolysin

Back 43

injures the bladder mucosa.

E. coli virulence factor

Front 44

Important UTI-relevant pathogenic feature of flagella

Back 44

allow the organism to be motile

E. coli virulence factor

Front 45

Important UTI-relevant pathogenic feature of LPS

Back 45

inhibits urinary tract peristalsis.

E. coli virulence factor

Front 46

Important UTI-relevant pathogenic feature of aerobactin

Back 46

siderophore which allows iron acquisition in the iron poor environment of the urinary tract

E. coli virulence factor

Front 47

important virulence factors that contribute to Proteus mirabilis' UTI pathogenicity

Back 47

Urease
Alkaline urine

Front 48

Important UTI-relevant pathogenic feature of urease

Back 48

splits urea into ammonia and carbon dioxide making the environment more hospitable. The pH can be increased from 7 up to 9.

Proteus mirabilis virulence factor

Front 49

Important UTI-relevant pathogenic feature of alkaline urine

Back 49

promotes the precipitation of phosphate, carbonate and magnesium. This
causes the formation of struvite stones that often form large staghorn calculi. The stones
are a great hiding place for Proteus, and they become a permanent source of bacteria,
which can produce more urease, which makes the urine alkaline and precipitates the
formation of more stones. These stones also lead to urinary stasis, which promotes
bacterial multiplication.

Front 50

If you have alkaline urine, what organism likely caused the UTI?

Back 50

Proteus mirabilis

Front 51

Which of Klebsiella's virulence factors contributes to its UTI pathogenicity?

Back 51

large capsule made in the presence of abundant glucose (i.e. uncontrolled diabetes)

Front 52

Which of Staphylococcus saprophyticus' virulence factors contributes to its UTI pathogenicity?

Back 52

adherence to uroepithelial cells

Front 53

Most important host defense against UTI

Back 53

normal urinary flow

Front 54

Mechanical factors predisposing to UTI

Back 54

short urinary tract (females)
close proximity to perianal and vulvar regions (females)
obstruction/flow impedance (stones, BPH, diverticula or strictures, neurogenic bladder)
reflux (esp. in kids)
foreskin (males)
urinary tract manipulation/mucosal injury (catheters)

Front 55

Genetic factors predisposing to UTIs

Back 55

-HLA type, P blood group phenotype and ABO/secretor status (on vaginal epithelial cells and mucus in females)
-density of receptors for the mannose sensitive or mannose resistant fimbriae

Front 56

2 types of type 2 pili

Back 56

P pili
X adhesions

Front 57

What do P pili do?

Back 57

bind to neutral glycolipids of the globoside series

Front 58

What do X adhesins do?

Back 58

bind to different globosides and are not well understood

Front 59

Which type of fimbriae are associated with renal colonization?

Back 59

Type 2

Front 60

Hormonal factors predisposing to UTIs

Back 60

Progesterone both dilates the upper collecting system and decreases peristalsis.
Postmenopausal estrogen deficiency
In pregnancy, the baby presses on the bladder

Front 61

Immunologic/tissue factors predisposing to UTIs

Back 61

renal medulla is a "desert" where complement and polys do not function

Front 62

Behavioral factors predisposing to UTIs

Back 62

sexual intercourse
anal sex
diaphragm/spermicide use
voiding practices
possibly carbonated beverages

Front 63

Characteristics of urine protecting against UTIs

Back 63

acidic pH,
high urea content,
extremes of osmolality

Front 64

Host defenses against UTIs

Back 64

normal urinary flow
mucosal integrity and bacteriocidal activity
urine (low pH, high urea content, extreme osmolality)
inhibitors of adherence.

Front 65

Inhibitors of adherence to GU epithelia

Back 65

Tamm-Horsfall protein
Bladder mucopolysaccharide
Secretory IgA
Prostatic secretions

Front 66

UTI Dx

Back 66

White Blood Cells in the Urine
And
105 bacteria per ml of urine on
culture

Front 67

Cystitis Dx

Back 67

White Blood Cells in Urine
And
102-103 bacteria per ml of urine
on culture if symptoms are
present

Front 68

If you see white cell casts in someone's urine, it's indicative of...

Back 68

kidney involvement

Front 69

What are some problems and pitfalls in diagnosing UTIs?

Back 69

• Poor collection methods
• Delayed culture
o In the absence of a urinalysis performed at the same time as
urine culture, interpreting the results of a positive urine culture
is dangerous!
• Vagaries of urine flow
• Prior antibiotic use

Front 70

Untreated UTIs can cause these complications:

Back 70

• Sepsis
• Low birth weight infants/premature labor
• Progressive renal parenchymal loss/renal scarring
• Renal calculi
• Perinephric/renal abscesses
• Prostatitis

Front 71

Treatment of UTI

Back 71

• Relieve obstructions
• Antibiotics that reach a high concentration in the urine (e.g., Septra, quinolones and cephalosporins).
• The duration of the therapy is dependent on the level and sites of infection, as well as complications.
o Cystitis is usually treated for 3 – 5 days.
o Pyelonephritis is usually treated for 2 weeks.
o Recurrent pyelonephritis and prostatitis require 6 weeks of treatment.

Front 72

How long is cystitis usually treated for?

Back 72

3-5 days

Front 73

How long is pyelonephritis usually treated for?

Back 73

2 weeks

Front 74

How long is recurrent pyelonephritis and prostatitis treated for?

Back 74

6 weeks

Front 75

the Tamm-Horsfall protein is...

Back 75

secreted by cells of the ascending loop of Henle.
has mannose containing side chain that bind to E. coli with type I pili (mannose sensitive pili) and S fimbriae.

Front 76

what does the bladder mucopolysaccharide do?

Back 76

decreases bacterial adherence

Front 77

what do prostatic secretions do?

Back 77

inhibit bacterial growth

Front 78

Characteristics of a eukaryotic cell

Back 78

a true nucleus,
multiple chromosomes,
membrane-bound organelles,
and 80s ribosomes

Front 79

Which four kingdoms belong to Domain Eukarya

Back 79

Animalia
Plantae
Protista
Fungi

Front 80

What two domains used to make up Domain Prokaryotae?

Back 80

Bacteria and Archaea

Front 81

Which domain did Eukarya branch off from?

Back 81

Archaea

Front 82

Characteristic of cells in Domain Archaea

Back 82

living in extreme environments

Front 83

Which domain do all parasites belong to?

Back 83

Domain Eukarya

Front 84

Def'n of protozoa

Back 84

single-celled, eukaryotic organisms

Front 85

Which two protozoa phyla contain important human parasites?

Back 85

Phylum Sarcomastigophora and Apicomplexan

Front 86

How are protozoa subdivided?

Back 86

Based on their means of locomotion.

Front 87

What type of reproduction do protozoa undergo?

Back 87

Asexual reproduction

Front 88

Is the severity of the disease related to the infecting dose of protozoa?

Back 88

No, because it multiplies inside the host.

Front 89

Which 2 (of 3) subphyla of Sarcomastigophora are medically important?

Back 89

Mastigophora
Sarcodina

Front 90

Phylum Sarcomastigophora is composed of...

Back 90

amoeboid and [animal-like] flagellated protozoans

Front 91

What do Mastigophora use for locomotion?

Back 91

Flagella

Front 92

What do Sarcodina use for locomotion?

Back 92

Pseudopods

Front 93

Examples of Mastigophora

Back 93

Giardia,
Trypanosoma
Trichomonas vaginalis
Leishmania

Front 94

Examples of Sarcodina

Back 94

Entamoeba histolytica

Front 95

Dzs caused by Trypanosoma

Back 95

African Sleeping Sickness and Chagas Dz

Front 96

What causes African Sleeping Sickness and Chagas Dz?

Back 96

Trypanosoma (brucei and cruzi, respectively)

Front 97

All members of phylum Apicomplexan are...

Back 97

intracellular parasites

Front 98

What do Apicomplexans use for locomotion?

Back 98

They are nonmotile.

Front 99

How do Apicomplexans penetrate host cells?

Back 99

Via a complex of organelles at the apex of their cells

Front 100

How do apicomplexans reproduce?

Back 100

capable of both sexual and asexual reproduction, have complex life cycles

Front 101

Examples of Apicomplexans

Back 101

Toxoplasma, Plasmodium, Crytosporidium, Cyclospora and Babesia

Front 102

Which agent causes East African sleeping sickness?

Back 102

Trypanosoma brucei rhodesiense

Front 103

Which agent causes West African sleeping sickness?

Back 103

Trypanosoma brucei gambiense

Front 104

How is African sleeping sickness transmitted?

Back 104

tsetse fly (Glossina species)

Front 105

Why is African sleeping sickness produced in waves of parasitemia?

Back 105

antigenic variation of the VSG (variant surface glycoprotein)

Front 106

What is the natural history of African sleeping sickness?

Back 106

CNS involvement in death

Front 107

Which African sleeping sickness (East or West) progresses more rapidly (weeks to months, as opposed to months to years)?

Back 107

East

Front 108

Which type of African sleeping sickness (East or West) are tourist hunters more likely to get and why?

Back 108

East, because that's where the game parks, and reserves are located.

Front 109

What is another name for American trypanosomiasis?

Back 109

Chagas disease

Front 110

What transmits American trypanosomiasis?

Back 110

Reduviid bug, aka kissing bug or assassin bug

Front 111

Where is the Reduviid bug native?

Back 111

South and Central America

Front 112

How does the Reduviid bug infect a host?

Back 112

biting and then defecating, usually when host is asleep.
Host rubs feces into skin, eyes, or mouth

Front 113

Why does Chagas dz hit low income populations more than other populations?

Back 113

The Reduviid bug lives in cracks in substandard housing.

Front 114

How many stages does Chagas dz have?

Back 114

3: acute, intermediate, chronic

Front 115

Romana's sign is a sign of what dz?

Back 115

acute infection with Chagas dz

Front 116

What is Romana's sign?

Back 116

acute swelling, often near one of the eyes, where a host has suffered a bite from the Reduviid bug and the feces have entered the mucosa.

Front 117

What are symptoms of Chagas dz?

Back 117

Romana's sign
fever
fatigue
weight loss

Front 118

How long does it take for symptoms of Chagas dz to resolve?

Back 118

4-8 weeks

Front 119

What percentage of people with Chagas dz show symptoms in the acute phase?

Back 119

1%

Front 120

What percentage of people with Chagas dz develop the chronic phase (after 10-20 years)?

Back 120

1/3

Front 121

What happens in the intermediate phase of Chagas dz?

Back 121

host has no sx
organism multiplying in macrophages in the GI and heart

Front 122

What are symptoms of chronic infection with Chagas dz?

Back 122

heart: enlargement and alteration in rate and rhythm, leads to heart failure and arrest
GI: megaesophagus and megacolon lead to constipation and difficulty swallowing

Front 123

Tx of acute phase Chagas dz

Back 123

nifurtimox and benznidazole : cure 50%

Front 124

Tx of chronic phase Chagas Dz

Back 124

supportive measures, symptom relief

Front 125

Where do Leishmania live?

Back 125

phagolysosome of macrophages
(they are strict intracellular pathogens)

Front 126

How are Leishmania transmitted?

Back 126

bite of the phlebotomine sand fly

Front 127

What are the 3 classes of disease caused by Leishmania?

Back 127

cutaneous leishmaniasis,
mucocutaneous leishmaniasis
and visceral leishmaniasis

Front 128

Where is cutaneous leishmaniasis found?

Back 128

the Old World and the New World

Front 129

What about the Leishmania species that causes cutaneous leishmaniasis limits its growth to the skin?

Back 129

Cannot grow at temperatures above 35 degrees

Front 130

How does cutaneous leishmaniasis present?

Back 130

one or more sores on the skin that heal spontaneously over time (months to years)

Front 131

How long does it take a cutaneous leishmaniasis sore to heal?

Back 131

months to years, but they heal spontaneously

Front 132

What 3 organisms cannot grow above 35 degrees?

Back 132

Leishmania (cutaneous type)
Mycobacterium marinum,
Sporothrix schenckii

Front 133

Where is mucocutaneous leishmaniasis found?

Back 133

Amazon forest and central plain of South America

Front 134

What causes mucocutaneous leishmaniasis?

Back 134

L. braziliensis

Front 135

How does mucocutaneous leishmaniasis present?

Back 135

single or several lesions,
perhaps a disfiguring metastasis of oronasopharyngeal mucosa...
(due to the low body temperature at this location and a defective CMI response)

Front 136

What causes visceral leishmaniasis?

Back 136

L. donovani complex

Front 137

How does visceral leishmaniasis disseminate?

Back 137

Via the blood stream, infecting the reticuloendothelial system (which, when infected chronically, loses its lymphocytic response)

Front 138

What is Kala Azir?

Back 138

Hindi for black poison
another name for visceral leishmaniasis
named after the dz that turns people's feet, hands, face and abdominal skin black

Front 139

What is the untreated mortality rate for visceral leishmaniasis?

Back 139

70-90%

Front 140

Which species of Leishmania is capable of growth at core temperatures?

Back 140

L. donovani (causes visceral leishmaniasis)

Front 141

How is Babesiosis transmitted?

Back 141

bite of the Ixodes tick

Front 142

Where do Babesia species undergo their life cycle?

Back 142

Inside RBCs

Front 143

Some stages of Babesia species' life cycle resemble what other type of infection?

Back 143

Plasmodium
except they differ in that in Babesiosis, no schizonts are produced

Front 144

Manifestations of Babesiosis

Back 144

most are asymptomatic
fever, chills, myalgia,
hepatosplenomegaly and anemia

Front 145

Babesiosis is more severe in what type of patients?

Back 145

Asplenic

Front 146

Babesiosis is often misdiagnosed as...

Back 146

malaria (in regions where malaria is prevalent)

Front 147

Where in the U.S. is Babesia found?

Back 147

Northeast (Nantucket island)

Front 148

Tx for Babesiosis

Back 148

clindamycin and quinine

Front 149

Where is Cyclospora usually found?

Back 149

tropical and subtropical regions

Front 150

How is Cyclospora transmitted?

Back 150

infected imported food

Front 151

How does Cyclospora present?

Back 151

Watery diarrhea that can be severe

Front 152

Tx for Cyclospora

Back 152

trimethoprim-sulfamethoxazole

Front 153

How long does Cyclospora last, untreated?

Back 153

12 weeks, but may relapse

Front 154

Can Cyclospora be treated with trimethoprim-sulfamethoxazole?

Back 154

Yes

Front 155

Can Cryptosporidium be treated with trimethoprim-sulfamethoxazole?

Back 155

No

Front 156

What Kingdom are Helminths a part of?

Back 156

Kingdom Animalia

Front 157

How many worm phyla are there?

Back 157

3

Front 158

How many parasitic worm phyla are there?

Back 158

2

Front 159

Are helminthes single-celled or multicellular?

Back 159

Multicellular (they are often large)

Front 160

Where do helminthes multiply?

Back 160

Outside the host (though they can live, metamorphose and travel within the host)

Front 161

Which of the protozoa have a bimodal presentation in the population?

Back 161

Helminthes.
Most have few worms and little dz, while some have high worm-loads and severe dz

Front 162

Where is the highest helminth prevalence?

Back 162

Developing countries,
in which infection leads to large economic impact

Front 163

Describe flatworms

Back 163

dorsoventrally flattened
have no body cavity
usually lack skeletal, circulatory, and respiratory systems

Front 164

Which systems do most flatworms lack?

Back 164

Skeletal
Circulatory
Respiratory

Front 165

What are the 2 classes of flatworms?

Back 165

Cestoda (tapeworms)
Flukes (trematoda)

Front 166

Examples of tapeworms (Cestodas)

Back 166

Taenia saginata
Taenia solium
Diphyllobothrium latum
Echinococcus

Front 167

What are the 2 types of flukes (Trematodas)?

Back 167

Blood flukes
Tissue flukes

Front 168

Examples of blood flukes

Back 168

Schistosoma mansoni
Schistosoma japonicum
Schistosoma haematobium

Front 169

Examples of tissue flukes

Back 169

Fasciola hepatica
Clonorchis (Opisthorchis)
Paragonimus westermani

Front 170

Phylogeny of fasciola hepatica

Back 170

Tissue fluke
Class Trematoda
Phylum Platyhelminthes
Kingdom Animalia

Front 171

Phylogeny of Schisosoma haematobium

Back 171

Blood fluke
Class Trematoda
Phylum Platyhelminthes
Kingdom Animalia

Front 172

Phylogeny of Clonorchis

Back 172

Tissue fluke
Class Trematoda
Phylum Platyhelminthes
Kingdom Animalia

Front 173

Phylogeny of Taenia solium

Back 173

Class Cestoda
Phylum Platyhelminthes
Kingdom Animalia

Front 174

Phylogeny of Echinococcus

Back 174

Class Cestoda
Phylum Platyhelminthes
Kingdom Animalia

Front 175

Phylogeny of Diphyllobothrium latum

Back 175

Class Cestoda
Phylum Platyhelminthes
Kingdom Animalia

Front 176

Which 2 worm phyla (of the kingdom animalia) have parasitic members?

Back 176

Phylum Platyhelminthes (flatworms)
Phylum Nematoda (roundworms)

Front 177

Examples from Phylum Nematoda

Back 177

Necator americanus
Ancylostoma duodenal
Ascaris
Anisakis
Strongyloides
Trichinella spiralis
Trichuris
Enterobius vermicularis
Dracunculus medinensis
Wuchereria bancrofti
Brugia malayi
Oncocerca volvulus

Front 178

Phylogeny of Necator americanus

Back 178

Phylum Nematoda
Kingdom Animalia

Front 179

Phylogeny of Ancylostoma duodenal

Back 179

Phylum Nematoda
Kingdom Animalia

Front 180

Phylogeny of Ascaris

Back 180

Phylum Nematoda
Kingdom Animalia

Front 181

Phylogeny of Anisakis

Back 181

Phylum Nematoda
Kingdom Animalia

Front 182

Phylogeny of Strongyloides

Back 182

Phylum Nematoda
Kingdom Animalia

Front 183

Phylogeny of Trichinella spiralis

Back 183

Phylum Nematoda
Kingdom Animalia

Front 184

Phylogeny of Trichuris

Back 184

Phylum Nematoda
Kingdom Animalia

Front 185

Phylogeny of Enterobius vermicularis

Back 185

Phylum Nematoda
Kingdom Animalia

Front 186

Phylogeny of Dracunculus medinensis

Back 186

Phylum Nematoda
Kingdom Animalia

Front 187

Phylogeny of Wuchereria bancrofti

Back 187

Phylum Nematoda
Kingdom Animalia

Front 188

Phylogeny of Brugia malayi

Back 188

Phylum Nematoda
Kingdom Animalia

Front 189

Phylogeny of Oncocerca volvulus

Back 189

Phylum Nematoda
Kingdom Animalia

Front 190

What is Trichinella spiralis' main reservoir?

Back 190

Domestic pigs

Front 191

Where does Trichinella spiralis spend most of its life?

Back 191

as an intracellular parasite

Front 192

How is Trichinella spiralis transmitted?

Back 192

its viable larvae are ingested in raw/undercooked meats.
inside the host, digestive enzymes release the larvae and they develop into adults

Front 193

How is Trichinella spiralis disseminated?

Back 193

Adult females shed larvae into bloodstream and lymphatics,
larvae encyst in muscle cells

Front 194

How does Trichinella spiralis present?

Back 194

light infections: asx
intestinal invasion: diarrhea, vomiting, ab pain
larval migration into muscle: fever, splinter hemorrhages, eosinophilia, rash, facial edema

Front 195

Complications of Trichinella spiralis

Back 195

myocarditis
pneumonitis
CNS infection
(life-threatening!)

Front 196

Tx Trichinella spriralis

Back 196

none specific,
but mebendazole administered early may reduce number of larvae

Front 197

Where is Dracunculus medinensis found?

Back 197

rural Africa

Front 198

What is the maximum length Dracunculus medinensis can be?

Back 198

3 feet

Front 199

How is Dracunculus medinensis transmitted?

Back 199

as larvae in copecods in drinking water
after ingestion, copecods (crustaceans) die and release the larvae

Front 200

How is Dracunculus medinensis disseminated?

Back 200

Larvae penetrate the stomach and intestinal wall, and mature/reproduce is abdominal cavity and retroperitoneal space

Front 201

How does Dracunculus medinensis present?

Back 201

A blister on the skin (usually legs) 1 year after infection, formed by female adult worms, which must be slowly extracted when the lesion comes in contact with water

Front 202

What happens to adult female Dracunculus medinensis worms after reproduction?

Back 202

They form blisters on legs that hopefully come in contact with water containing copecods (so that the larvae can infect them)

Front 203

What happens to adult male Dracunculus medinensis worms after reproduction?

Back 203

They die

Front 204

What are 3 species of Filarial worms?

Back 204

Wuchereria bancrofti
Brugia malayi
Onchocerca volvulus

Front 205

In filariasis, where are the worms located?

Back 205

Lymphatics and subcutaneous tissue

Front 206

How many species of filarial worms infect humans?

Back 206

8, but we only need to know the 3 that cause the most morbidity

Front 207

How are filarial worms transmitted?

Back 207

Larvae are transmitted by the bite of an infected arthropod

Front 208

What is the vector for filarial worms?

Back 208

Arthropod

Front 209

How long can filarial worms live inside a human host?

Back 209

several years

Front 210

How do adult filarial worms infect their vector?

Back 210

They produce microfilariae that infect arthropods when they bite the host

Front 211

What filarial worms are the major causes of lymphatic filariasis?

Back 211

Wuchereria bancrofti
Brugia malayi

Front 212

Where is Wuchereria bancrofti found?

Back 212

tropical regions

Front 213

Where is Brugia malayi found?

Back 213

Asia

Front 214

How do Wuchereria bancrofti and Brugia malayi present?

Back 214

mostly asymptomatic
some develop lymphedema and elephantiasis

Front 215

Are antihelminthic agents effective against lymphatic filariasis?

Back 215

They can kill the microfilariae (help prevent transmission), but the pathology is caused by the death of adult worms, so prevention of infection is the only effective treatment

Front 216

Where does Onchocerca volvulus live within the host?

Back 216

in nodules in subcutaneous tissue

Front 217

Where is Onchocerca volvulus endemic?

Back 217

Africa
parts of Latin America
parts of Middle East

Front 218

How is Onchocerca volvulus transmitted?

Back 218

black fly (Simulium)

Front 219

How does Onchocerca volvulus present?

Back 219

subcutaneous nodules
pruritis
dermatitis
ocular lesions that progress to blindness

Front 220

In Africa, parts of Latin American and the Middle East, an antihelminthic agent is given yearly to kill the larval form of a helminth and its most serious manifestation. What is the helminth, the drug, and the manifestation?

Back 220

Ochocerca volvulus
ivermectin
blindness

Front 221

How do intestinal protozoa reproduce?

Back 221

Asexually inside the host (therefore the infecting dose doesn't determine the severity of infection)

Front 222

How does Cryptosporidium parvum reproduce?

Back 222

Sexually (unlike all other intestinal protozoa)

Front 223

Which three protozoa are intestinal (that we covered)?

Back 223

Entamoeba histolytica
Giardia lamblia
Cryptosporidium parvum

Front 224

Where in the world is Entamoeba histolytica found?

Back 224

worldwide, highest incidence in developing countries?

Front 225

Groups at risk of Entamoeba histolytica infection?

Back 225

Male homosexuals
travelers
recent immigrants
institutionalized populations

Front 226

What is the reservoir of Entamoeba histolytica?

Back 226

Humans only

Front 227

Are all Entamoeba strains pathogenic?

Back 227

No, E. dispar is a morphologically indistinguishable zymodeme from the pathogenic E. histolytica

Front 228

What is a zymodeme?

Back 228

subtype of a species that can only be separated from other subtypes by their isoenzyme pattenrs

Front 229

How is Entamoeba histolytica transmitted?

Back 229

In fecal cysts contaminating water, food, or hands

Front 230

Where do Entamoeba histolytica's trophozites migrate once ingested?

Back 230

Large intestine

Front 231

How long can Entamoeba cysts last in the external environment?

Back 231

days to weeks (the walls of the cysts convey resistance to many environmental influences)

Front 232

How long can Entamoeba trophozoites last in the external environment?

Back 232

They can't! They must be encased in cysts in order to survive.

Front 233

What are the possible courses of infection with Entamoeba, once the cysts have been ingested?

Back 233

1) asx carrier with noninvasive infection (often E. dispar)
2) intestinal dz from trophozoites invading the mucosa
3) bloodstream dissemination to liver, brain, lungs

Front 234

What makes up the cyst wall of Entamoeba histolytica?

Back 234

Chitin

Front 235

Are Entamoeba histolytica cysts resistant to chlorine and cold water?

Back 235

Yes

Front 236

Are Entamoeba histolytica cysts resistant to heat and dessication?

Back 236

No

Front 237

Are Entamoeba histolytica cysts removed by filtration?

Back 237

Yes

Front 238

What shape are the cysts of Entamoeba histolytica?

Back 238

spherical, often with a halo

Front 239

How many nuclei do mature Entamoeba histolytica cysts have?

Back 239

4

Front 240

How big are Entamoeba histolytica cysts?

Back 240

12 to 15 micrometers

Front 241

What are characteristic features of Entamoeba histolytica's nuclei in cysts?

Back 241

centrally located karyosomes (nucleolus)
fine, uniformly distributed peripheral chromatin

Front 242

Which species' trophozoites are the active, motile, feeding stage?

Back 242

Entamoeba histolytica

Front 243

Are Entamoeba histolytica's trophozoites aerobic?

Back 243

No, they are anaerobic and LACK MITOs

Front 244

Which species' trophozoites ingest RBCs (called erythrophagocytosis)

Back 244

Pathognomic for Entamoeba histolytica (even differentiates it from E. dispar!)

Front 245

What does Entamoeba histolytica do to tissue and how?

Back 245

It causes necrosis (invasive dz), by the production of multiple virulence factors

Front 246

How many nuclei do Entamoeba histolytica trophozoites have?

Back 246

1

Front 247

What are characteristic features of Entamoeba histolytica's trophozoites?

Back 247

Nuclei: centrally placed karyosome
uniformly distributed peripheral chromatin
Cytoplasm: granular, "ground glass" appearance

Front 248

How big are Entamoeba histolytica's trophozoites?

Back 248

15 to 20 micrometers (range 10-60)
more elongated in diarrheal stool

Front 249

How does Entamoeba histolytica present?

Back 249

Asx
dysentery ("amebic dysentery") - usually protracted diarrhea
abscesses at distant sites (liver, lung, cutaneous) "extraintestinal amebiasis"

Front 250

What organism causes "flask-shaped ulcers" on the colon wall (viewed on sigmoidoscopy)?

Back 250

Entamoeba histolytica

Front 251

Tx Entamoeba histolytica

Back 251

metronidazole

Front 252

Can Entamoeba histolytica trophozoites survive at high oxygen pressures?

Back 252

No

Front 253

Where are Entamoeba histolytica found in a cross-section of an intestinal infection?

Back 253

At the margins between healthy and dead tissue

Front 254

How do Entamoeba histolytica trophozoites reach the liver?

Back 254

via portal vein

Front 255

Dx of Entamoeba histolytica

Back 255

SEROLOGY of abscess, find a cyst

Front 256

Does Entamoeba histolytica infection provoke effective Abs?

Back 256

No (Abs are not protective)

Front 257

Does Giardia lamblia cause epidemic or endemic dz?

Back 257

Both, worldwide

Front 258

How is Giardia lamblia transmitted?

Back 258

mostly person-to-person
water-borne (fecal/oral)

Front 259

Groups at increased risk for Giardia lamblia infection

Back 259

male homosexuals
kids in daycare
food handlers
mental institution patients
travelers to endemic regions (like St. Petersburg, Russia)
hikers and campers without proper water purification

Front 260

Reservoirs of Giardia lamblia

Back 260

humans
beavers in watershed areas
muskrats
dogs
other animals

Front 261

How many trophozoites does each Giardia lamblia cyst yield?

Back 261

2 trophozoites produced from each cyst

Front 262

How do Giardia lamblia trophozoites multiply?

Back 262

longitudinal binary fission
(either free in small intestine, or attached to mucosa by ventral sucking disk)

Front 263

Are Giardia lamblia cysts resistant to water and chlorine?

Back 263

Yes

Front 264

Are Giardia lamblia cysts resistant to heat and dessication?

Back 264

No

Front 265

Are Giardia lamblia cysts removed by filtration?

Back 265

Yes

Front 266

What shape are Giardia lamblia cysts?

Back 266

Oval

Front 267

How many nuclei do mature Giardia lamblia cysts have?

Back 267

4

Front 268

How big are Giardia lamblia cysts?

Back 268

8-12 micrometers

Front 269

Are Giardia lamblia trophozoites aerobic?

Back 269

No, they are anaerobic and LACK MITOs

Front 270

Tx Giardia lamblia

Back 270

Metronidazole

Front 271

Which stage of Giardia lamblia is the active, motile feeding stage that causes pathology?

Back 271

trophozoite

Front 272

Do Giardia lamblia's trophozoites cause invasive dz or inflammation?

Back 272

No

Front 273

How do Giardia lamblia trophozoites attach to enterocytes?

Back 273

Adhesive disk (ventral sucking disk)

Front 274

Can Giardia lamblia trophozoites survive in the environment?

Back 274

No

Front 275

How many nuclei do Giardia lamblia trophozoites have? describe them

Back 275

2, with a large, central karyosome (nucleolus)
Looks like eyeballs!

Front 276

How big are Giardia lamblia trophozoites?

Back 276

9-21 micrometers

Front 277

How does Giardia lamblia present?

Back 277

can be asx
can be protracted diarrhea and/or steatorrhea
can involve partial villous atrophy
can cause lactase deficiency (that can persist after treatment)
can cause Malabsorptive syndrome

Front 278

What is Malabsorptive syndrome?

Back 278

Steatorrhea, dissaccharide deficiency and B12 malabsorption

Front 279

What causes malabsorptive syndrome?

Back 279

Giardia lamblia

Front 280

Dx Giardia lamblia

Back 280

-find it in feces (found in 50% of an infected person's stools, 90% if you check 3 stools from different days)
-antigen detection kits (Abs against cyst or trophozoite antigens): ELISA or immunofluorescence assay
-duodenal sampling (string test)

Front 281

What is the sensitivity and specificity of Giardia lamblia antigen detection tests?

Back 281

Sensitivity: 90-99%
Specificity: 95-100%

(when compared to stool microscopy)

Front 282

What causes traveler's diarrhea, seasonal diarrhea and diarrhea in daycare centers?

Back 282

Cryptosporidium

Front 283

Is Cryptosporidium obligately human or zoonotic?

Back 283

Zoonotic

Front 284

Cryptosporidium is a apicomplexan, which makes it related to

Back 284

Toxoplasma gondii

Front 285

How is Cryptosporidium transmitted?

Back 285

fecal/oral
drinking/recreational water - outbreaks in waterparks, community swimming pools, day care centers,
food (chicken salad)

Front 286

How does Crytosporidium reproduce?

Back 286

Both sexually and asexually

Front 287

How many Cryptosporidium sporozoites are contained in each sporulated oocyte?

Back 287

4

Front 288

What happens after Cryptosporidium sporulated oocytes are ingested?

Back 288

Excystation release sporozoites, that parasitize intestinal epithelial cells, within which they multiply (schizogony or merogony) and then undergo sexual reproduction (gametogony)

Front 289

What is schizogony/merogony?

Back 289

asexual multiplication

Front 290

What is gametogony?

Back 290

sexual reproduction

Front 291

What are male Cryptosporidium called?

Back 291

microgamonts

Front 292

What are female Cryptosporidium gametes called?

Back 292

macrogamonts

Front 293

Fusion of a macrogamont and microgamont produces an

Back 293

oocyst, that sporulates in the infected host

Front 294

Are oocysts of Cryptosporidium infective upon excretion?

Back 294

Yes

Front 295

Are Cryptosporidium oocysts resistant to chlorination?

Back 295

Yes

Front 296

What color do Cryptosporidium stain on modified acid-fast stain?

Back 296

Bright red, often variable staining

Front 297

How big are Cryptosporidium cysts?

Back 297

3-5 microns

Front 298

Which portions of the GI tract does Cryptosporidium mainly colonize?

Back 298

Jejunum and ileum

Front 299

Are Cryptosporidium trophozoites intra or extracellular?

Back 299

Neither, really, they are covered by the intestinal microvilli, but not inside them

Front 300

How does Cryptosporidium present in normal hosts? in immunocompromised?

Back 300

normal host - mild, self-limited (weeks) watery diarrhea, anorexia, weight loss

immunocompromised - severe, protracted diarrhea, potentially fatal

Front 301

Dx Cryptosporidium

Back 301

find oocyst in stool with acid fast or auramine stain or monoclonal AB with IF

Front 302

Tx Cryptosporidium

Back 302

none for normal hosts,
for the immunodeficient, nitazoxanide (antiparasitic for children 1-11yo)

Front 303

What causes malaria?

Back 303

Protozoans from the Plasmodium genus

Front 304

Which 4 Plasmodium species cause dz in humans?

Back 304

Plasmodium falciparum
P. vivax
P. ovale
P. malariae
Also P. knowlesi, but only in Indonesia/West Pacific Islands

Front 305

What Plasmodium species is limited in distribution to Indonesia and other Western Pacific Islands?

Back 305

Plasmodium knowlesi

zoonotic from monkeys

Front 306

Which species of Plasmodium causes the most severe (life-threatening) malaria?

Back 306

P. falciparum

Front 307

Which RBCs does P. falciparum infect?

Back 307

All ages (therefore, high parasitemia)

Front 308

Which RBCs do P. ovale and P. vivax infect?

Back 308

Reticulocytes only

Front 309

Which RBCs do P. malariae infect?

Back 309

Mature RBCs

Front 310

How does plasmodium falciparum cause tissue damage?

Back 310

mature trophozoites and schizonts are sequestered in microvascular system

Front 311

Which species of Plasmodium produce hypnozoites that are latent in the liver?

Back 311

P. vivax and P. ovale

Front 312

How long after infection can P. vivax and P. ovale relapse?

Back 312

5 years

Front 313

Duffy negative individuals are intrinsically resistant to what Plasmodium species?

Back 313

Plasmodium vivax,
P. vivax uses the Duffy blood receptor to enter RBCs

Front 314

How can you differentiate P. vivax and P. ovale?

Back 314

P ovale can infect Duffy negative individuals but P. vivax cannot.

Front 315

What characteristics do P. vivax and P. ovale share?

Back 315

Appearance, life cycle, clinical presentation and treatment

Front 316

What drugs are P. falciparum evolving resistance to?

Back 316

Chloroquine and Fansidar (pyrimethamine, sulfadiazene)

Front 317

What drugs are P. vivax evolving resistance to?

Back 317

Chloroquine

Front 318

Where are chloroquine-resistant P. vivax found?

Back 318

Indonesia and other places in Asia

Front 319

How long does P. malariae parasitemia persist?

Back 319

40 years, always low grade

Front 320

Which species of Plasmodium causes a glomerulonephritis?

Back 320

P. malariae

Front 321

Which Plasmodium species are less common?

Back 321

P. ovale and P. malariae

Front 322

Where is malaria endemic?

Back 322

Almost every country in the Southern world, including Mexico and South, middle east, China, India and South, excluding Australia

Front 323

When was malaria first documented?

Back 323

China in 1700 B.C.

Front 324

What % of the population lives in malaria-endemic parts?

Back 324

40%

Front 325

What % of those infected with malaria are symptomatic?

Back 325

20%, making the other 80% reservoirs for continued transmission

Front 326

Out of the 300-500 million affected with malaria each year, how many die?

Back 326

1.5-2.7 million

Front 327

When do children start showing malaria symptoms in endemic areas?

Back 327

between 4-8 months of age

Front 328

Sx that a child is infected with malaria

Back 328

fever, irritability, poor feeding, vomiting, diarrhea, convulsions

Front 329

What % of malaria-infected pregnant woman pass the dz to the placenta?

Back 329

30%

Front 330

Young children (less than 5 years old) with malaria are more or less likely to die from the dz than older children and adults?

Back 330

More likely

Front 331

What % of nonimmune, malaria-infected pregnant women deliver an infected baby?

Back 331

10%

Front 332

What % of semimmune, malaria-infected pregnant women deliver an infected baby?

Back 332

less than 3%

Front 333

Are primigravid (1st pregnancy) or multigravid (not 1st pregnancy) pregnant women more susceptible to severe malaria?

Back 333

Primigravid are more susceptible, unless they have AIDS, in which they are equally susceptible

Front 334

Why are multigravid pregnant women less susceptible to severe malaria than primigravid pregnant women?

Back 334

Acquisition of humoral immunity against PfEMP1 variants that mediate binding to chondroitin sulfate A in the intervillous spaces.

Front 335

What is the most common acute febrile illness that is imported?

Back 335

Malaria

Front 336

T/F: Malaria manifests within 6 months of returning from an endemic area

Back 336

False, it can manifest months to years after leaving an endemic area

Front 337

T/F: Malaria prophyllaxis prevents infection

Back 337

False, it is not foolproof

Front 338

T/F: Malarial Dz is often more severe in chronically exposed people than a traveler

Back 338

False

Front 339

Methods of malaria transmission

Back 339

mosquitoes
local infection
blood transfusion
IVDA (IV drug abuse)

Front 340

How many stages do Plasmodium species have, what are they and where do they occur?

Back 340

Two
1. Asexual (schizogony) in human liver and RBCs
2. Sexual (sporogony) in Anopheles mosquito

Front 341

What is the vector of Plasmodium?

Back 341

Anopheles mosquito

Front 342

When in the day do most malaria-transmitting mosquito bites occur?

Back 342

between dusk and dawn

Front 343

Which gender of Anopheles mosquitoes bite humans, and what does the other gender subsist on?

Back 343

Females bite,
males subsist on nectar

Front 344

Which species of mosquito transmits San Diego's malaria?

Back 344

Anopheles freeborni

Front 345

Which form of Plasmodium is passed to humans from mosquitos?

Back 345

Sporozoites

Front 346

What human organ does Plasmodium infect?

Back 346

Liver - sporozoites infect hepatocytes and proliferate into merozoites (that are released to invade RBCs)

Front 347

Describe the Plasmodium asexual cycle

Back 347

In RBCs, merozoites develop into trophozoites that eat Hb, mature, and turn into schizonts that release more merozoites

Front 348

What form of Plasmodium invade RBCs?

Back 348

Merozoites

Front 349

Describe the Plasmodium sexual cycle

Back 349

Within a mosquito, gametocytes undergo genetic recombination (and potential spread of acquired drug resistance)

Front 350

What are dormant Plasmodium called?

Back 350

Hypnozoites

Front 351

Which species of Plasmodium have a dormant hynozoite stage?

Back 351

P. vivax and P. ovale

Front 352

What pathogenic ability is conferred to P. vivax and P. ovale by their hypnozoites?

Back 352

Recurrent infection (relapse)

Front 353

Where are hypnozoites stored?

Back 353

Liver

Front 354

Which cycle (sexual or asexual) involves spread of acquired drug resistance?

Back 354

Sexual

Front 355

Which Plasmodium life cycle (sexual or asexual) involves antigenic variation?

Back 355

Asexual

Front 356

Which species of Plasmodium display antigenic variation?

Back 356

P. falciparum for sure, likely other species

Front 357

In what forms do Plasmodium adhere to the postcapillary endothelium (causing microvascular dz)?

Back 357

mature trophozoites and schizonts are peripherally sequestered

Front 358

Which organs suffer from Plasmodium microvascular dz?

Back 358

Brain, heart, mesentery, lungs, kidney, placenta

Front 359

What receptor does Plasmodium falciparum use to enter cells?

Back 359

Sialic acid, though it also has a sialic acid-independent entry mechanism

Front 360

Which form of Plasmodium is the "ring stage"?

Back 360

trophozoites

Front 361

Which type of Plasmodium replication (schizogony or sporogony) occurs in mosquitoes?

Back 361

Sporogony

Front 362

What is a motile, elongated Plasmodium zygote called?

Back 362

Ookinetes

Front 363

Where do Plasmodium microgametes and macrogametes generate zygotes?

Back 363

stomach of mosquitos

Front 364

Where do Plasmodium ookinetes develop into oocysts?

Back 364

Midgut wall of the mosquito

Front 365

After the oocysts release sporozoites within the mosquito GI tract, where do the sporozoites migrate?

Back 365

Mosquito's salivary glands

Front 366

How many smears for Plasmodium should come back negative before ruling malaria out of a diagnosis?

Back 366

At least twice a day for at least 3 days

Front 367

What additional treatment is required for P. ovale and P. vivax compared to other Plasmodium species?

Back 367

tissue schizonticide (since they have a hepatic phase)

Front 368

What % of malarial infections contain multiple Plasmodium species?

Back 368

5-7%

Front 369

Which Giemsa smear (thick or thin) is more sensitive to detecting Plasmodia?

Back 369

Thick (because they can be concentrated 10-15 fold)

Front 370

Which Giemsa stain (thick or thin) is better for identifying Plasmodium morphology?

Back 370

Thin

Front 371

Which species of Plasmodium shows Schuffner's dots?

Back 371

P. vivax

Front 372

Which species has banana-shaped gametocytes?

Back 372

Plasmodium falciparum

Front 373

What does the ring trophozoite of Plasmodium falciparum look like?

Back 373

Thready ring, multiple infections, double dots, applique forms

Front 374

If ameoboid trophozoites and schizonts of a Plasmodium species are seen on peripheral blood smear, which species can be ruled out?

Back 374

Plasmodium falciparum, because its trophozoites and schizonts are stuck inside the body clogging microvasculature

Front 375

How many merozoites are contained in a P. vivax schizont?

Back 375

12-24 merozoites

Front 376

What shape are the gametocytes of P. vivax?

Back 376

round to oval and fills the cell, containing scattered brown pigment

Front 377

What techniques are available for malaria dx?

Back 377

Microscopic ID
Ag capture kits
PCR based techniques
Fluorescent techniques
Serological tests

Front 378

How do malarial Ag capture kits work?

Back 378

dipstick test from finger-prick blood sample
results in 10-15 minutes
expensive
low sensitivity for less concentrated (<100 parasites per mL)

Front 379

How do PCR based malaria tests work?

Back 379

detect DNA or MRNA sequences specific to Plasmodium
very high (near 100%) sensitivity and specificity
take hours and technical expertise to perform
expensive

Front 380

When are PCR based malaria tests most useful?

Back 380

Genotyping to distinguish new from recurrent infection

Front 381

What are the disadvantages of fluorescent malaria tests?

Back 381

Less sensitive and specific than microscopy
low sensitivity for less concentrated (<100 parasites per mL)
cannot differentiate species
require expensive microscope and skilled personnel

Front 382

What are malarial serological tests useful for?

Back 382

Epidemiological, but not diagnostic purposes

Front 383

What are the stages of classic malarial periodic fevers paroxysms?

Back 383

prodrome
cold stage
hot stage
sweating stage

Front 384

Sx of malaria prodrome stage

Back 384

malaise,
myalgias,
viral-like syndrome

Front 385

Sx of malaria cold stage

Back 385

shaking chills

Front 386

Sx of malaria hot stage

Back 386

102-104 degree fever for several hours
tachycardia
hypotension
headache
nausea
abdominal pain
delirium

Front 387

Sx of malaria sweating stage

Back 387

diaphoresis
resolution of fever
severe fatigue
sleep

Front 388

How long is the cycle of P. vivax, P. ovale, and P. falciparum?

Back 388

48 hours

Front 389

How long is the cycle of P. malariae?

Back 389

72 hours

Front 390

What are the classic sx of malaria when paroxysms do not occur?

Back 390

intermittent, irregular fever
anemia
jaundice
splenomegaly

Front 391

Does malaria occur more often with paroxyms (synchronous infection) or without them (asynchronous infection)?

Back 391

Without them (asynchronous)

Front 392

What lab findings suggest malaria?

Back 392

Elevated BUN/Cre
Hyponatremia
Hypoglycemia
Evidence of hemolysis
Proteinuria
Bilirubin in urine
Anemia
Thrombocytopenia
Infected RBCs
Reticulocytosis

Front 393

What infection is suggested by Hypoglycemia, evidence of hemolysis,
Proteinuria, Anemia, and Reticulocytosis?

Back 393

Malaria

Front 394

All species of malaria can cause which clinical symptoms?

Back 394

Anemia, dehydration, electrolyte abnormalities, and acute splenic rupture

Front 395

What complications of malaria can occur with any of the species?

Back 395

Anemia,
dehydration,
electrolyte abnormalities,
acute splenic rupture

Front 396

Which complications of malaria are specific to P. falciparum?

Back 396

cerebral malaria (impaired state of consciousness c or s seizures - 20-30% mortality)
pulm. edema and ARDS - 15% mortality)
severe renal failure
Blackwater fever

Front 397

What is the mechanism for P. falciparum-induced pulmonary edema and ARDS?

Back 397

sequestration of parasitized RBCs in the lung.
increased leakage from pulm. vasculature induced by cytokines

Front 398

What causes the severe renal failure associated with P. falciparum infection?

Back 398

microvascular dz,
hypovolemia,
hemolysis

Front 399

What is Blackwater fever?

Back 399

assoc. with P. falciparum infection
large amounts of Hb and malarial pigment in urine making it appear black

Front 400

How does malaria cause anemia?

Back 400

Hemolysis during schizogony
Absorption of Ab on non-parasitized RBCs (lysis mediated by complement)
Suppression of hematopoiesis by cytokines
G6PD def-associated hemolysis

Front 401

How does malaria cause hypoglycemia?

Back 401

decreased glycogen stores due to decreased food intake, glucose consumption by plasmodia and TNF-alpha or quinine-stimulated hyperinsulinemia

Front 402

Why are P. falciparum infections more severe than infections from other Plasmodium species?

Back 402

hyperparasitemia
microvascular dz

Front 403

What causes P. falciparum to sequester in the microvasculature?

Back 403

secreted proteins like PfEMP1 that bind endothelial receptors (CD36, ICAM-1, CSA on placenta),
PfEMP1 is concentrated on RBC membrane in knobs that cause Ag variation and cytoadherence

Front 404

Besides causing pathology, what advantage is conferred to P. falciparum by its peripheral sequestration?

Back 404

Prevents sequestration in the spleen

Front 405

How does P. falciparum evade immune detection?

Back 405

Antigenic variation via PfEMP and Rifins

Front 406

What factors should be considered in choosing a schizonticide for treating malaria?

Back 406

expected resistance pattern of organism,
severity of infection,
patient's immune status

Front 407

What does supportive care consist of for severe cases of malaria?

Back 407

monitor for complications (hypoglycemia, anemia, seizures, septicemia, renal failure, acidosis, resp. failure)
gentle IV rehydration (if low risk of pulm. edema)
possibly blood transfusions, hemodialysis, mechanical ventilation, BDZ therapy and ABX

Front 408

What confers complete immunity to malaria?

Back 408

Nothing

Front 409

What type of immunity develops in response to repeated P. falciparum infection?

Back 409

Ab (against blood stages)
and cell-mediated (against liver and blood stages)

Front 410

What type of Abs confer anti-disease immunity to malaria?

Back 410

Ab to parasite toxic factors (glycosylphosphatidyl inositol anchors)

prevent clinical illness

Front 411

What type of Abs confer anti-infection immunity to malaria?

Back 411

Abs to parasite proteins

correlates to the ability to clear parasites after inoculation (prevent parasitemia)

Front 412

T/F: Immunity to one species of Plasmodium confers immunity to all species

Back 412

False, immunity is species specific

Front 413

T/F: Immunity to malaria fades after clearing the infection

Back 413

True, fades within weeks to months

Front 414

What genetic conditions protect against severe (life-threatening) malaria?

Back 414

sickle cell anemia
lack of duffy blood group
G6PD def
Thalassemias
South East Asian ovalocytosis

Front 415

Candidate Ags for malaria vaccine

Back 415

circumsporozoite protein (CSP)
merozoite surface protein 1 (MSP-1)
erythrocyte-binding antigen 175 (EBA 175)
apical-merozoite Ag (APA-1)
gametocyte Ags (Pfs25)
pre-erythrocyte liver-stage Ag 3 (LSA-3)

Front 416

Factors to consider in choosing chemoprophyllaxis for malaria

Back 416

is there significant risk to warrant it?
patient's drug allergies
whether they are at risk for drug-resistant malaria

Front 417

Countries where there is not a risk of contracting drug-resistant P. falciparum malaria

Back 417

Dominican Republic
Haiti
Central America north of Panama Canal
Egypt
Middle Eastern countries

Front 418

What is the time course for malaria chemoprophyllaxis?

Back 418

at least 1-2 weeks before travel to endemic areas (so any side effects can be evaluated and treated before departure),
continuing through trip,
4 weeks after leaving endemic area

Front 419

What is the malaria chemoprophyllaxis regimen for travel to areas NOT at risk for chloroquinine-resistant P. falciparum?

Back 419

Once weekly chloroquine

Front 420

What is the malaria chemoprophyllaxis regiment for travel to areas at risk for chloroquinine-resistant P. falciparum?

Back 420

Mefloquine

Front 421

Which schizonticide prevents P. vivax and P. ovale relapses?

Back 421

Primaquine

Front 422

Which population should primaquine NOT be used?

Back 422

G6PD def (causes severe hemolytic anemia)

Front 423

What herbal remedy is used to treat malaria?

Back 423

Artemisinin (Qinghaosu, Chinese wormwood)

Front 424

What medications make up Fansidar?

Back 424

Pyrimethadine and sulfadoxine

Front 425

What are the 9 drugs used for malaria-related treatment?

Back 425

Chloroquine
Primaquine
Artemisinin
Quinine/quinidine
malarone
tetracycline/doxycycline
Fansidar
Proguanil (not available in US)
Clindamycin

Front 426

How can you prevent malaria?

Back 426

avoid contact with mosquitoes from dusk to dawn (use bed nets, pre-treat with permethrin or deltamethrin)
cover up with clothing and mosquito nets
insect repellant (esp. DEET 30-35%, and Permethrin for clothes and skin)

Front 427

The common name for Nematodes

Back 427

Roundworms

Front 428

Common name for Trematodes

Back 428

Flukes

Front 429

Common name for platyhelminthes

Back 429

Flatworms

Front 430

Common name for Cestodes

Back 430

Tapeworms

Front 431

Common name for Schistosomes

Back 431

Blood flukes

Front 432

What are the 2 major types of Helminths?

Back 432

Nematodes (roundworms) and
Platyhelminthes (flatworms)

Front 433

What are the 2 types of platyhelminths?

Back 433

Trematodes (flukes) and
Cestodes (tapeworms)

Front 434

What are the 2 types of Trematodes?

Back 434

Schistosomes (blood flukes) and
Tissue flukes

Front 435

How are Nematodes divided?

Back 435

Whether migration in the body is a part of the life cycle

Front 436

Which Nematodes migrate in the body?

Back 436

Ascaris lumbricoides
Ancyclostoma/Necator
Strongyloides stercoralis

Front 437

For which Nematodes is Migration in the body not part of the life cycle?

Back 437

Trichuris trichiura
Enterobius vermicularis
Anisakis species

Front 438

Examples of Schistosomes

Back 438

Schistosoma mansoni
Schistosoma haematobium
Schistosoma japonicum

Front 439

Examples of tissue flukes

Back 439

Clonorchis sinensis
Paragonimus westermani
Fasciola hepatica

Front 440

Examples of Cestodes

Back 440

Taenia solium (pork tapeworm)
Taenia saginata (beef tapeworm)
Diphyllobothrium latum (fish tapeworm)
Echinococcus (dog tapeworm)

Front 441

What is the pork tapeworm?

Back 441

Taenia solium

Front 442

What is the beef tapeworm?

Back 442

Taenia saginata

Front 443

What is the fish tapeworm?

Back 443

Diphyllobothrium latum

Front 444

What is the dog tapeworm?

Back 444

Echinococcus

Front 445

(relevant) Phylogeny of Schistosoma japonicum

Back 445

Animalia
Helminths
Platyhelminthes
Trematodes (flukes)
Schistosomes (blood flukes)

Front 446

Phylogeny of Enterobius vermicularis

Back 446

Helminths
Nematodes that do not migrate in body

Front 447

Phylogeny of Ancyclostoma/Necator

Back 447

Helminths
Nematodes that migrate in the body

Front 448

Phylogeny of Echinococcus

Back 448

Helminths
Platyhelminthes
Cestode
(dog tapeworm)

Front 449

Phylogeny of Paragonimus westermani

Back 449

Helminths
Platyhelminthes
Trematodes
Tissue fluke

Front 450

Phylogeny of Fasciola hepatica

Back 450

Helminths
Platyhelminths
Trematodes
Tissue fluke

Front 451

How long are helminthes?

Back 451

Wide variation in size
Strongyloides is just visible to naked eye
while Dracunculus is 60 cm long

Front 452

Do helminths elicit protective immunity?

Back 452

Yes, but ONLY after many years/decades
AND developmental stages have stage-specific antigens

Front 453

Do helminthes replicate within the host?

Back 453

No, though they can persist long-term.
Exception: Strongyloides

Front 454

Only 1 helminth can replicate in the host- which one?

Back 454

Strongyloides

Front 455

Why is treating helminth infections difficult?

Back 455

Antibiotics inhibiting macromolecular synthesis are not effective

Front 456

How are helminths distributed in human communities?

Back 456

Aggregated distribution (minority of people harbor majority of worms)

Front 457

Can helminth infections be fatal?

Back 457

No, they just cause morbidity

Front 458

Does severity of worm burden correlated with severity of dz?

Back 458

Yes

Front 459

What type of immune cells are abundant in a helminth infection?

Back 459

Eosinophils

Front 460

Long term helminth infection can exacerbate... what?

Back 460

Poor nutrition

Front 461

Is host response to helminths adaptive?

Back 461

No, it can itself mediate damage at sites of parasite accumulation

Front 462

What chronic sequelae occur from persistent schistosomiasis?

Back 462

Hepatosplenic dz

Front 463

What chronic sequelae occur from persistent filariasis?

Back 463

Lymphedema
Elephantiasis

Front 464

What does elephantiasis result from?

Back 464

Chronic filariasis

Front 465

What is concomitant immunity and what type of infection causes humans to have it?

Back 465

Concomitant immunity is when a host is protected against newly invading larvae while tolerating an established adult worm load.
Occurs with helminth infections

Front 466

can macroparasites exhibit antigenic variation and divergence?

Back 466

Only able to generate new antigen variants very slowly
(generation time is almost equivalent to host's generation time)

Front 467

How do macroparasites achieve genetic heterogeneity?

Back 467

genetic variation in the human community (where a few hosts are predisposed to heavy infection)

Front 468

How do microparasites achieve genetic heterogeneity?

Back 468

antigenic variation and divergence

Front 469

What does the acquisition of immunity to helminths depend on?

Back 469

Age
Differences in exposure
Susceptibility to infection
Ability to mount effective immunological responses

Front 470

What defense strategies to helminths have?

Back 470

-avoid initial induction of the damaging host response
-neutralize selected parts of immune system
-short term defenses (physical, or antioxidant enzymes)

Front 471

What strategies allow parasites to avoid the initial induction of the damaging host response?

Back 471

-uptake of host antigens
-interfere with Ag processing to induce immunological unresponsiveness/tolerance

Front 472

Which helminths take up host antigens and what antigens do they take up?

Back 472

Schistosomes
host MHC and decay-accelerating factor?

Front 473

Which helminths interfere with Ag processing to induce immunological unresponsiveness/tolerance?

Back 473

Filaria worms and Ascaris
release cystatin-like molecule and aspartic proteinase inhibitor which blocks Ag processing

Front 474

Which helminths have immunoglobulin-cleaving proteases?

Back 474

Dirofilaria, Fasciola and Schistosoma

Front 475

Which helminths interfere with complement action?

Back 475

Taenia
Echinococcus

Front 476

How does Taenia interfere with complement action?

Back 476

releases highly sulfated proteoglycans which activate complement in fluid phase

Front 477

How does Echinococcus interfere with complement action?

Back 477

secretes elastase inhibitor that blocks neutrophil attraction by C5a

Front 478

How do Taenia and filaria worms interfere with specific T cell subsets?

Back 478

They release prostacyclin and PGE2, which may inhibit T cell proliferation

Front 479

Examples of physical (short-term) defenses of helminths

Back 479

thick tegument and cuticle
Fasciola rapidly turns over its surface glycocalyx

Front 480

Which enzymes are antioxidant?

Back 480

Superoxide dismutase
Glutathione S-transferase

Front 481

Which Platyhelminths are hermaphrodites?

Back 481

All except Schistosomes (which have separate sexes)

Front 482

Blood fluke hosts

Back 482

Snail and human (both during their life cycle)

Front 483

Tissue fluke hosts

Back 483

Snail, human, and another (either fish, water plants, or crustaceans)

Front 484

Describe life cycle of Schistosoma

Back 484

Eggs in feces/urine
Eggs hatch, releasing miracidia
Miracidia inhabit snails as sporocysts
Cercariae released, free-swimming into water
Penetrate human skin (becoming schistosomulae when lose tail) and migrate to portal blood venules and mature
Paired adult worms lay eggs that circulate in liver, shed in stool

Front 485

how do Schistosoma enter humans?

Back 485

Through skin while human is in infected water

Front 486

Where does each Schistosoma species migrate once inside human host?

Back 486

mesenteric venules
(S. japonicum - sup. mesenteric veins draining Small Intestine)
(S. mansoni - sup. mesenteric veins draining large intestine)
(S. haematobium - venous plexus of bladder)

Front 487

Which gender of Schistosoma worm is larger?

Back 487

Females (7-20mm)

Front 488

Where do female Schistosomes deposit their eggs?

Back 488

small venules of the portal and perivesical system

Front 489

Which Schistosomes are excreted in feces?

Back 489

S. mansoni
S. japonicum

Front 490

Which Schistosomes are excreted in urine?

Back 490

S. haematobium

Front 491

What are the stages of Schistosome development called before and after human entry?

Back 491

Before: cercariae (with tails in water)
After: Schistosomulae (no tails)

Front 492

Where within the human host do Schistosomes mature?

Back 492

Portal blood in liver

Front 493

What are the stages of Schistosome development called before, during and after snail infection?

Back 493

Before: Miracidia
During: sporocysts
After release: Cercariae

Front 494

Where is Schistosoma mansoni endemic?

Back 494

Central Africa, Egypt, South America and Caribbean

Front 495

At-risk populations for acute Schistosoma mansoni infection

Back 495

Tourists to an endemic area

Front 496

How does Katayama Fever present and what causes it?

Back 496

Fever, anorexia, abdominal pain, lymphadenopathy

Schistosoma mansoni

Front 497

Which stage of Schistome development is responsible for chronic Schistosoma mansoni infection?

Back 497

Eggs

Front 498

Sx of chronic Schistosoma mansoni infection

Back 498

colonic polyps
granulomas in liver leading to pipestem fibrosis
(portal hypertension with variceal bleeding due to presinusoidal block in portal flow)
ascites
gross splenomegaly
growth retardation

Front 499

Schistosoma mansoni dx

Back 499

finding egg in feces

Front 500

Schistosoma tx (all 3 species)

Back 500

Praziquantel

Front 501

Which species displays eggs with a lateral spine?

Back 501

Schistosoma mansoni

Front 502

What type of immunity do the eggs of Schistosoma mansoni induce?

Back 502

Cell-mediated immunity
(formation of granulomata in bowel and liver)

Front 503

Where is Schistosoma haematobium found?

Back 503

Middle East
Africa

Front 504

Which species of Schistosoma's eggs are laid in the renal veins (and where else would they be laid)?

Back 504

S. haematobium eggs in renal veins
S. mansoni and S. japonicum eggs in portal veins
Excess S. japonicum eggs in brain

Front 505

Where is S. japonicum endemic?

Back 505

Far East

Front 506

Sx. of S. japonicum infection

Back 506

fever, cough, abdominal pain, diarrhea, hepatospenomegaly, (same as S. mansoni) PLUS cerebral symptoms, including convulsions

Front 507

Is Schistosoma zoonotic?

Back 507

yes!

Front 508

What species of schistosomes cause cercarial dermatitis?

Back 508

Avian schistosoma japonicum species

Front 509

What causes "swimmer's itch"?

Back 509

Schistosomiasis

Front 510

Where is Clonorchis sinensis endemic?

Back 510

China, Korea, Taiwan and Vietnam

Front 511

Reservoirs of Clonorchis sinensis

Back 511

dogs and cats

Front 512

How do humans acquire Clonorchis infection?

Back 512

Raw or undercooked fish with metacercariae under scales

Front 513

Where do adult Clonorchis sinensis reside?

Back 513

Biliary duct

Front 514

Where does Clonorchis sinensis encyst?

Back 514

Duodenum

Front 515

How do the targets of Schistosome cercariae differ from the targets of Clonorchis sinensis and Fasciola hepatica?

Back 515

Cercariae from Schistosome species target human skin, while cercariae from Clonorchis and Fasciola target carp and water plants, respectively.

Front 516

What is the Chinese liver fluke?

Back 516

Clonorchis sinensis

Front 517

Where are Clonorchis sinensis' eggs?

Back 517

Feces

Front 518

Sx of Clonorchis sinensis infection

Back 518

ab pain, diarrhea and nausea (acute)
pyogenic cholangitis and pancreatitis (chronic)
Due to inflammation and intermittent obstruction in intestines

Front 519

Chronic infection with Clonorchis sinensis predisposes the host to what?

Back 519

Cholangiocarcinoma of the liver

Front 520

What developmental stages does Clonorchis sinensis go through while inside its snail host?

Back 520

Miracidia
Sporocysts
Rediae
Cercariae

Front 521

How long can Clonorchis sinensis live in distal bile dults?

Back 521

30-40 years!

Front 522

What does the Clonorchis sinensis egg look like?

Back 522

Small and operculated (operculum at narrow end of egg)

Front 523

What is the lung fluke?

Back 523

Paragonimus westermani

Front 524

Where is Paragonimus westermani found?

Back 524

Far East
though other Paragonimus species are found elsewhere

Front 525

What is the second host of Paragonimus westermani?

Back 525

Crab

Front 526

Reservoirs of Paragonimus westermani

Back 526

domestic and wild animals (pigs, dogs, feline species)

Front 527

How do humans acquire Paragonimus westermani?

Back 527

Ingestion of metacercaria in raw/undercooked crab

Front 528

Where do Paragonimus westermani migrate once ingested?

Back 528

Lung

Front 529

Sx of Paragonimus westermani infection

Back 529

diarrhea, ab pain, fever, cough, hsm (acute)
TB-like pulmonary dz w/ cough and hemoptysis (chronic)

Front 530

Where can you find eggs of Paragonimus westermani?

Back 530

Feces or sputum

Front 531

Does an infected person cough up/poop out embryonated eggs of Paragonimus westermani or unembryonated eggs?

Back 531

Unembryonated eggs

Front 532

Where do the metacercariae of Paragonimus westermani encyst?

Back 532

Duodenum, before passing through to lungs, brain or striated muscles

Front 533

Time from infection to oviposition (egg laying) for Paragonimus westermani

Back 533

65-90 days

Front 534

How long can Paragonimus westermani infections persist in humans?

Back 534

20 years

Front 535

Appearance of Paragonimus westermani egg

Back 535

flat on one side,
operculum clearly visible at large end

Front 536

What is the sheep liver fluke?

Back 536

Fasciola hepatica

Front 537

Where is Fasciola hepatica found?

Back 537

Worldwide

Front 538

Where are adult Fasciola hepatica found?

Back 538

Biliary duct

Front 539

Where do the metacercariae of Fasciola hepatica encyst?

Back 539

Watercress

Front 540

How do humans acquire Fasciola hepatica?

Back 540

ingestion of watercress with metacercariae

Front 541

How long does it take Fasciola hepatica after ingestion to find the bile duct?

Back 541

Months

Front 542

Sx of Fasciola hepatica infection

Back 542

fever, RUQ pain, eosinophilia (acute, while fluke is finding biliary duct)
biliary obstruction and inflammation (chronic)

Front 543

Appearance of Fasciola hepatica eggs

Back 543

ellipsoidal
small, barely visible operculum at upper end

Front 544

What type of anitfungal is amphotericin B?

Back 544

Polyene

Front 545

What fungi are resistant to amphotericin B?

Back 545

none

Front 546

What antifungal is first line for mucormycosis?

Back 546

Amphotericin B

Front 547

How does amphotericin B exhibit its antifungal action?

Back 547

Binds to ergosterol in membrane, altering permeability of cell membrane (bacteriocidal)

Front 548

What is the advantage of newer amphotericin drugs?

Back 548

Complexed with lipids/liposomes to decrease renal toxicity,
BUT VERY EXPENSIVE $$$

Front 549

Which antifungal is used for severe, life-threatening fungal infections?

Back 549

Amphotericin B

Front 550

Which drug acts synergistically with amphotericin B, and what is this combo used to treat?

Back 550

Flucytosine
Serious cryptococcal infections in high-risk patients

Front 551

What are the side effects of Amphotericin B?

Back 551

Nephrotoxicity ( in 80% of patients! dose dependent, cumulative)
Fever, chills, HA, N/V, hypoTN 1-3 hours post-IV infusion
Hypokalemia, hypomagnesia, weight loss, malaise, anemia

Front 552

How is amphotericin B administered?

Back 552

IV
(poor GI absorption)

Front 553

Why are serum concentration measurements useless for amphotericin?

Back 553

Most of the drug is bound to plasma lipoproteins or membrane sterols

Front 554

T 1/2 of amphotericin

Back 554

LONG (days to weeks)

Front 555

Amphotericin excretion

Back 555

Slowly in urine (don't adjust dose for renal/liver failure)
Not cleared by dialysis

Front 556

What antifungal agent is antagonistic to Amphotericin B?

Back 556

Azoles

Front 557

Describe the nephrotoxicity resulting from amphotericin B

Back 557

occurs in more than 80% of patients
increase in BUN and serum cre, decrease in creatinine clearance
find RBC casts and WBC casts and albumin in urine
irreversible renal failure in large doses (>2g)

Front 558

What antifungal agent, when coadministered with amphotericin B, lessens the amphotericin dose required?

Back 558

Flucytosine (5FC)

Front 559

What types of infections does 5FC treat?

Back 559

systemic Candida or Cryptococcus infections

Front 560

What types of fungus are resistant to 5FC?

Back 560

Many, resistance develops rapidly when it is used alone

Front 561

Mechanism of 5FC

Back 561

short answer: interferes with DNA synthesis.
long answer: fluorine analog of cytosine
deaminated to 5-fluorouracil (5-FU)
converted to 5-fluorodeoxyuridylic acid monophosphate, which is a noncompetitive inhibitor of thymidylate synthetase

Front 562

Side effects of 5FC

Back 562

depresses bone marrow fcn (anemia, leukopenia, thrombocytopenia)
GI (vomiting, diarrhea, nausea)

Front 563

What is the upper limit of safe serum levels of 5FC?

Back 563

120 micrograms/mL to avoid bone marrow depression

Front 564

How is 5FC administered?

Back 564

Orally, good GI absorption

Front 565

Where does 5FC distribute?

Back 565

Well-distributed!
CSF, aqueous humor, joints, peritoneal fluid

Front 566

Excretion of 5FC

Back 566

70-90% unchanged in urine
cleared by dialysis
MUST be dose-adjusted for decreased renal failure

Front 567

Mech for resistance to 5FC

Back 567

1 step chromosomal resistance due to loss of deaminase

Front 568

Mech of echinocandins

Back 568

prevent glucan synthesis in fungal cell wall

Front 569

What do Echinocandins treat?

Back 569

Aspergillus
Fluconazole-resistant Candida

(NO activity against Cryptococcus, Fusarium, or Rhizopus)

Front 570

Echinocandin admin

Back 570

IV only

Front 571

Disadvantage of treating with Echinocandins

Back 571

very expensive ($300/day)

Front 572

What is the most common cause of pneumonia in AIDs patients?

Back 572

Pneumocystis jiroveci (fungus)

Front 573

What is unusual about P. jiroveci?

Back 573

cannot be cultured
newly classified as fungus based on rRNA sequences

Front 574

Pneumocystic jiroveci treatment

Back 574

High dose Septra
if sulfa-allergic, Dapsone and trimethoprim
for prophyllaxis, Septra or pentamidine (inhalation)

Front 575

Side effects of high dose Septra

Back 575

allergic skin rashes

Front 576

Side effects of Pentamidine

Back 576

renal or bone marrow toxicity

Front 577

Mechanism of Azoles

Back 577

depletes membrane of ergosterol
inhibit cytochrome P450-dependent 14-alpha-lanosterol demethylase enzyme

Front 578

2 groups of azoles and drugs in each group

Back 578

Triazoles (fluconazole, itraconazole, voriconazole)
Imidazoles (clotrimazole, ketoconazole, micronazole)

Front 579

2 most widely used triazoles

Back 579

Fluconazole, voriconazole

Front 580

What advantages do triazoles have over earlier imidazoles?

Back 580

better pharmacokinetics
safer
better efficacy treating systemic fungal infection

Front 581

Imidazoles treat...

Back 581

cutaneous fungal infections
vulvovaginal infection

Front 582

Fluconazole (Diflucan) treats...

Back 582

oral/vagina Candida (if not responding to nystatin or clotrimazole)
non-life-threatening Candida infections like esophagitis
Hepatosplenic candidiasis
Cryptococcal infections
Coccidioidal meningitis

Front 583

Itraconazole (Sporanox) treats..

Back 583

Fungal infections in immunocompromised or normal patients
Blastomycosis
Histoplasmosis
Aspergillosis
Onychomycosis (nail fungus)

Front 584

Voriconazole (Vfend) treats...

Back 584

severe aspergillosis
Fluconazole-resistant candidal infections

Front 585

Posaconazole (Noxafil) treats...

Back 585

Prevention of aspergillosis and candida infections in immunocompromised (>13 yo)

Front 586

What is unique about posaconazole?

Back 586

broader spectrum of activity than other triazoles
may cover strains resistant to other antifungal agents

Front 587

Side effects of azoles

Back 587

GI (N/V, diarrhea) most common
Rash, HA
Mild elevation in LFTs (7% of patients)
Hepatotoxicity leading to liver failure and death(rare)
Drug interactions (esp. itraconazole, voriconazole)

Front 588

Itraconazole admin

Back 588

IV or PO (with acidic drinks or food)

Front 589

Excretion of itraconazole

Back 589

hepatic
NO dose-adjustment for renal/liver failure

Front 590

Fluconazole admin

Back 590

PO

Front 591

Fluconazole distribution

Back 591

well-distributed to CSF and tissues

Front 592

Excretion of fluconazole

Back 592

in urine, 80% unchanged
ADJUST dose for renal failure

Front 593

What is the drug of choice for Coccidiomycosis?

Back 593

Voriconazole

Front 594

Why is voriconazole the drug of choice for Coccidiodes?

Back 594

well absorbed but has lower CSF levels

Front 595

Does vorciconazole need dose-adjustment in renal/hepatic failure?

Back 595

Yes

Front 596

Ketoconazole side effects

Back 596

adrenal suppression
gynecomastia
hypocholesterolemia (can interfere with XOL synthesis)
hypothyroidism

Front 597

Definitive host

Back 597

host inhabited by the adult form of the parasite
(where sexual reproduction happens, if it happens)

Front 598

Intermediary/secondary host

Back 598

host inhabited by larval form

Front 599

For what Cestode is the human both the definitive and intermediary host?

Back 599

Taenia solium

Front 600

For what Cestode is the human only the definitive host?

Back 600

Taenia saginata

Front 601

Where is Taenia solium infection mostly seen?

Back 601

Mexico, Latin America, Eastern Europe, Africa, Asia

Front 602

What is the scolex?

Back 602

the head of a tapeworm

Front 603

Where in the human body does Taenia solium live?

Back 603

Small intestine, attached by its scolex.
Also can enter bloodstream and encyst elsewhere (cysticercosis, neurocysticercosis)

Front 604

How are Taenia (solium or saginata) eggs shed?

Back 604

Proglottids breaks off of their place attached to the small intestine, and eggs are released in the colon (excreted in feces)

Front 605

Dz caused by Taenia solium

Back 605

Cysticercosis

Front 606

How is Taenia solium acquired?

Back 606

eggs ingested, larvae hatch and penetrate intestinal wall

Front 607

What is neurocysticercosis?

Back 607

Taenia solium larvae encysted in the brain

Front 608

Neurocysticercosis sx

Back 608

vomiting, HA, visual changes, seizures (increased ICP)

Front 609

How is Taenia saginata acquired?

Back 609

ingestion of infected meat containing larvae

Front 610

Intermediary host of Taenia saginata

Back 610

Cattle

Front 611

How long can Taenia eggs survive in the environment?

Back 611

Days to months

Front 612

How long can cysticerci survive in the animal?

Back 612

Years

Front 613

Intermediary host of Taenia solium

Back 613

Humans
Pigs

Front 614

Average length of T. solium in intestines

Back 614

5m or less

Front 615

Average length of T. saginata in intestines

Back 615

2-7m

Front 616

How many eggs/gravid proglottids are passed in the stoll of a Taenia-infected person per day?

Back 616

approx 6

Front 617

Which Taenia species has more eggs?

Back 617

T. saginata (1,000-2,000)

T. solium has avg. 1,000

T. saginata's proglottids can produce up to 100,000 eggs, while T. solium's produce up to 50,000

Front 618

How many "suckers" on the scolex of Taenia species?

Back 618

4,
plus solium has a double row of hooks

Front 619

What is the largest human tapeworm and how long is it?

Back 619

Diphyllobothrium latum
10m

Front 620

What populations are most affected by Diphyllobothrium latum? Where in the world?

Back 620

those who eat raw or undercooked freshwater fish
Great Lakes, Scandinavia, W. Europe, Japan, S. America

Front 621

How long can Diphyllobothrium latum live in a host?

Back 621

up to 25 years

Front 622

Sx of Diphyllobothrium latum infection

Back 622

usually asx
pernicious anemia

Front 623

How does Diphyllobothrium latum cause pernicious anemia?

Back 623

release a chemical that interferes with intrinsic factor and Vit. B12 absorption

Front 624

What do Diphyllobothrium latum eggs look like?

Back 624

Oval/ellipsoidal, with an operculum at one end.
about 65 micrometers by 45 micrometers

Front 625

What do Diphyllobothrium latum proglottids look like?

Back 625

strands of visible length in feces, micro look like stacked things/palm tree trunk

Front 626

Intermediary host of Diphyllobothrium latum

Back 626

Copecod, or Freshwater crustacean
which is then ingested by a second intermediary host
such as minnows or small freshwater fish

Front 627

Where do Diphyllobothrium larvae develop into the infective stage?

Back 627

Fish flesh

Front 628

Where in the human body does Diphyllobothrium latum live?

Back 628

Small intestine

Front 629

How many eggs are passed in the feces of a Diphyllobothrium-infected person, per day?

Back 629

up to 1,000,000 eggs per day per worm

Front 630

Humans are only the intermediate host for

Back 630

Echinococcus

Front 631

What other animals can be the definitive host of Diphyllobothrium latum?

Back 631

other mammals

Front 632

What causes Hydatid dz?

Back 632

Echinococcus LARVAE

Front 633

Where is Echinococcus found?

Back 633

worldwide, esp. rural farming areas

Front 634

Echinococcus sx

Back 634

usually asx until cyst in liver grows so large that it causes problems (hydatid dz - obstructive jaundice)

Front 635

Hydratid dz tx

Back 635

surgical removal of cysts without breaking them
(breaking one and leaking fluid can cause anaphylaxis)

Front 636

What are the organisms called that form inside an Echinococcus cyst?

Back 636

protoscolices (singular: protoscolex), and daughter cysts

Front 637

How do dogs acquired Echinococcus?

Back 637

Ingestion of the cyst-containing organs of infected intermediate hosts

Front 638

What is the definitive host of Echinococcus?

Back 638

Dogs or other canids

Front 639

What is the intermediate host of Echinococcus?

Back 639

Sheet, goat, swine, cattle, horses, camel, and unfortunately humans

Front 640

Are nematodes segmented or unsegmented worms?

Back 640

Unsegmented

Front 641

Are nematodes hermaphrodites?

Back 641

No they have separate sexes

Front 642

How many larval molts do nematodes have?

Back 642

4

Front 643

What is Loeffler's syndrome?

Back 643

Transient pulmonary infiltrates and peripheral eosinophilia caused by nematodes that migrate through the lungs

Front 644

What is the largest nematode parasitizing the intestine and how long is it?

Back 644

Ascaris lumbricoides
35 cm

Front 645

Ascaris lumbricoides tx

Back 645

Narcotize with piperazine (since worm's death is slow)
Mebendazole

Front 646

Where is Ascaris found?

Back 646

One of the most common worldwide,
highest prevalence in tropical and subtropical regions, or areas with inadequate sanitation

Front 647

Where do the eggs of Ascaris mature?

Back 647

Soil

Front 648

How long can Ascaris eggs survive in the environment?

Back 648

up to 7 years

Front 649

What is the major complication of Ascaris infection?

Back 649

Obstruction

Front 650

Ascaris lumbricoides dx

Back 650

eggs in stool

Front 651

How is Ascaris transmitted?

Back 651

fecal/oral (ingestion of a developed fertilized egg)

Front 652

Where do adult Ascaris worms live?

Back 652

lumen of small intestine

Front 653

How many eggs/day are produced by female adult Ascaris worms?

Back 653

approx. 200,000

Front 654

How long must Ascaris eggs sit in soil before becoming fertilized and infective?

Back 654

18 days (in moist, warm, shaded soil) - several weeks (in dry, cold/hot, exposed soil)

Front 655

How long after ingestion does Ascaris establish in the small intestine?

Back 655

2-3 months

Front 656

Trace the path of Ascaris in the human host

Back 656

Fertile/infective eggs are ingested, larvae hatch and invade intestinal mucosa, then are carried via portal and systemic circulation to the lungs.
Mature in the lungs, ascend bronchial tree, get swallowed down again. Stop and stay as adult worms in small intestine

Front 657

How long do Ascaris adult worms live?

Back 657

1-2 years

Front 658

Which nematodes are considered hookworms?

Back 658

Necator americanus
Ancyclostoma duodenale

Front 659

What are viral capsids made of?

Back 659

protein

Front 660

Which is more stable, enveloped viruses or nonenveloped viruses?

Back 660

Nonenveloped
(more stable to dessication, detergents, alcohols and proteolytic enzymes)

Front 661

What are the two possible capsid structures and which virus fits neither?

Back 661

Helical (RNA only) and icosahedral.
Pox is neither

Front 662

What is the nucleocapsid?

Back 662

combo of capsid and nucleic acid

Front 663

What is a nonstructural protein?

Back 663

A protein encoded in viral DNA/RNA that is NOT incorporated into the baby viruses (virions) that are made.
Usually have a role in virus replication

Front 664

Which RNA virus is ds?

Back 664

reoviruses

Front 665

Tissue tropism

Back 665

the cells that a virus readily infects (therefore the cell has a receptor for that virus)

Front 666

What is CPE

Back 666

cytopathic effects (the distinctive morphology of infected cells)

Front 667

what are "susceptible" cells, vs. "permissive" cells? Which term is related to "productive" infections?

Back 667

"Susceptible" cells have the receptor for a virus, thus allowing its entry.
"Permissive" cells are cells in which the virus can produce progeny (thus making it a productive infection).

Front 668

What is an abortive infection and what 2 things cause it?

Back 668

no viral progeny produced
either: 1) nonpermissive cell,
2) defective virus (lacking some of necessary viral genes)

Front 669

What are enhancer elements?

Back 669

regulatory DNA or RNA sequences in a viral genome that bind specific TFs, leading to enhanced viral gene expression and replication

Front 670

Does HPV have a narrow or broad host range?
And what's special about it's permissivity?

Back 670

narrow host range (human epithelial cells)
transiently permissive (must wait until epithelial cell is terminally differentiated and synthesizing keratin)
results in RESTRICTIVE infection

Front 671

What persists in a latent viral infection, and what is this type of infection associated with?

Back 671

Viral genomes w/o infectious virions in host cells
Associated with vertical transmission

Front 672

What does it mean for a virus to have a "hit and run" strategy?

Back 672

It infects a cell, causes infection/dz, then is cleared by the immune system.
Must constantly find new susceptible hosts to survive

Front 673

What 2 mechanisms might be used by a virus to enter a cell?

Back 673

Receptor-mediated endocytosis
Fusion

Front 674

In receptor-mediated endocytosis, what facilitates the uncoating of virus?

Back 674

acidification of the endosome

Front 675

What ability must a virus have in order to undergo fusion with the host cell membrane?

Back 675

must be able to fuse at NEUTRAL pH

Front 676

What are the hallmark of viruses capable of fusion at neutral pH?

Back 676

Multinucleated giant cells or syncytia

Front 677

Must a viral genome completely uncoat before replication?

Back 677

In some species, yes, in others, no

Front 678

What must a negative sense RNA virus have in order to replicate?

Back 678

RNA-dependent RNA Polymerase

Front 679

Where do RNA viruses undergo replication, and what is the exception?

Back 679

cytoplasm
Orthomyxoviruses

Front 680

Where do DNA viruses undergo replication, and what is the exception?

Back 680

nucleus
Poxviruses

Front 681

what type of viruses can undergo reassortment?

Back 681

segmented viruses

Front 682

strategies used by viruses to utilize host metabolic machinery

Back 682

alternative reading frames
splicing/cleaving primary RNA transcripts yielding multiple distinct RNAs
multifunctional viral proteins

Front 683

in DNA viruses, immediate early gene products..

Back 683

regulate expression of other genes

Front 684

in DNA viruses, early gene products...

Back 684

are directly involved in replication of viral genome

Front 685

in DNA viruses, late gene products...

Back 685

are structural proteins of the virions

Front 686

if an animal virus is non-enveloped what kind of capsid does it have?

Back 686

icosahedral

Front 687

Which are more unique, the antigenic epitopes of an intact virus or a disrupted virus?

Back 687

Intact virus (they elicit type-specific neutralizing Abs)
disrupted viruses elicit group-specific Abs

Front 688

Picornavirus:
+/- ss/ds DNA/RNA
enveloped/naked
icosahedral/helical
rep. in cytoplasm/nucleus

Back 688

+ ss RNA
naked
icosahedral
cytoplasm

Front 689

Picornavirus genera

Back 689

Enteroviruses
Rhinoviruses
Hepatovirus (Hep A)
Cardioviruses

Front 690

Enterovirus species

Back 690

Coxsackieviruses A and B
Echoviruses
Polioviruses
other, unclassified enteroviruses

Front 691

At what pH are enteroviruses stable?
What are the implications?

Back 691

pH = 3
can infect the ileum (b/c can survive gastric acid)

Front 692

optimum enterovirus temperature for replication

Back 692

37 degrees

Front 693

At what temperature do enteroviruses get inactivated?

Back 693

50 degrees

Front 694

How can you differentiate Enteroviruses from Rhinoviruses?

Back 694

Enteroviruses are inactivated at 50 degrees, rhinoviruses are not

Front 695

Can enteroviruses survive in the environment (at room temperature)?

Back 695

Yes

Front 696

What times of year are peak enterovirus season?

Back 696

late summer, early autumn

Front 697

what are the most common manifestations of enterovirus infection?

Back 697

rash
aseptic meningitis

Front 698

How are enteroviruses transmitted?

Back 698

fecal-oral
for some (polio, coxsackie) also respiratory

Front 699

sx of aseptic meningitis

Back 699

HA,
fever,
stiff neck,
CSF pleocytosis,
CSF [protein] increases with decreasing cell count
normal CSF [glucose]

Front 700

CSF pleocytosis

Back 700

150-500 cells
polys predominate early
lymphocytes predominate late

sx of aseptic meningitis, seen in enterovirus infection

Front 701

Is poliovirus zoonotic?

Back 701

No, humans are only natural host

Front 702

Host range of poliovirus

Back 702

limited (by receptor presence) to cells of primate origin
-kidney, brain, spinal cord, small bowel

Front 703

Poliovirus type 1, 2 and 3 receptor

Back 703

-70-80kD integral membrane protein in the Ig superfamily, encoded on chr. 19
-attaches electrostatically to floor of "canyon" in poliovirus capsid
-binding results in loss of VP4 on virus membrane

Front 704

What is special about the poliovirus genome?

Back 704

VPg is covalently linked at its 5' end

Front 705

How is the poliovirus genome translated?

Back 705

single large 2207 AA polyprotein that is sequentially cleaved into 7-8 smaller viral proteins (by virus-encoded proteases)

Front 706

examples of poliovirus nonstructural proteins

Back 706

RNA polymerase
viral protease

Front 707

Functions of poliovirus viral protease

Back 707

cleave polyprotein into structural and nonstructural proteins
destroy cellular cap-binding protein (shutting off cellular protein synthesis)
eventually break down host polyribosomes and create larger viral polyribosomes

Front 708

in viral replication, which proceeds faster: protein synthesis or RNA synthesis?

Back 708

RNA synthesis,
(thus as soon as enough proteins are formed, RNA is encapsidated very rapidly)

Front 709

Does polio virion construction use or create energy? what are the steps?

Back 709

uses it.
step 1: capsomere assembly into procapsid [(VP1+VP3+VP0)5]12
step 2: nucleic acid entry, cleavage of VP0 into VP2 and VP4

only 1 in 200 of assembled virions is infectious (Very inefficient!)

Front 710

Are polioviruses released upon completion of the replication cycle?

Back 710

No, mature virions retained for several hours until cell "bursts" (due in part to activation of its lysosomal enzymes)

Front 711

What % of ppl infected with polio show sx? and why?

Back 711

5%
in 95% of people, neutralizing Abs are elicited at the minor (primary) viremia stage

Front 712

Dz caused by polio infection

Back 712

asx (95%)
abortive infection
aseptic meningitis
paralytic polio :(

Front 713

How does polio enter and spread to cause infection?

Back 713

most often ingested, infect small bowel mucosa (Peyer's patches)
spread to mesenteric lymph nodes-->blood (minor/primary viremia)
spread to liver, spleen, bone marrow and lymph nodes
IN PPL w/o healthy immunity (5%), heavy shedding leads to major/secondary viremia and abortive polio sx
-if passes BBB (<1%) --> aseptic meningitis, self-lmtd and resolves in 1 week
-if involves motor neurons (0.1%) -> paralytic polio

Front 714

Abortive polio sx

Back 714

fever
HA
vomiting
diarrhea or constipation
sore throat

Front 715

How does poliovirus reach motor neurons?

Back 715

either hematogenous (majority of cases) or via intra-axonal transport from peripheral sensory ganglia

Front 716

What is the neuropathology associated with paralytic polio?

Back 716

neuronophagia
PMNs surround and phagotcytose dying neurons

Front 717

What is bulbar polio?

Back 717

type of paralytic polio involving motor neurons and cranial nerves in medulla
(5-10% of patients with paralytic polio)
- can have paralyzed respiratory muscles and die

Front 718

What % of paralytic polio victims have permanent paralysis? what is the most common site?

Back 718

0.5%
legs

Front 719

How long are polio virions shed from the pharynx and in feces?

Back 719

pharynx: 3-4 weeks
feces: 5-6 weeks or longer

Front 720

Risk factors for polio infection

Back 720

poverty
crowding
unsanitary conditions
respiratory contact with infected person

Front 721

Are enteroviruses synergistic or antagonistic?

Back 721

Antagonistic (one enterovirus can interfere with another's infection - or vaccination)

Front 722

What is the relationship between age and severity of polio?

Back 722

Older people get more severe (more often paralytic) dz

Front 723

Does polio infection elicit effective immunity?

Back 723

yes, lifelong type-specific immunity and type-specific resistance to GI infection

Front 724

Why don't children under 6 months old get paralytic polio?

Back 724

maternal antibody

Front 725

Polio dx

Back 725

virus isolation and a rising Ab titer

Front 726

Polio-endemic regions

Back 726

Nigeria, India, Pakistan, Afghanistan

Front 727

Are monovalent (directed at type 1 or type 2 or 3) oral polio vaccines more effective than trivalent oral vaccines?

Back 727

yes

Front 728

Pros of Sabin polio vaccine

Back 728

GI immunity as well as systemic immunity
immunity is transmitted
oral admin = easier, better for epidemics
relatively inexpensive

Front 729

Cons of Sabin polio vaccine

Back 729

risk of paralytic dz in immunocompromised ppl and their contacts
infection by other enterovirus can interfere

Front 730

Pros of Salk polio vaccine

Back 730

induces humoral immunity
no risk of paralytic dz
no shedding (no risk to contacts)
no interference from other enterovirus

Front 731

Cons of Salk polio vaccine

Back 731

requires booster doses and subq admin (decreased acceptance)
no GI immunity
more expensive

Front 732

Does polio infect latently or "hit and run"?

Back 732

Hit and run
no persistance of virus in host after immunity developed

Front 733

What does ECHOvirus stand for and how many serotypes are there?

Back 733

Enteric
Cytopathic
Human
Orphan
29 serotypes

Front 734

Is Echovirus zoonotic?

Back 734

don't generally cause dz in animals

Front 735

dzs caused by Echovirus

Back 735

aseptic meningtis
rash
generalized infections in newborn
echovirus 16- Boston exanthema

Front 736

What causes Boston exanthema, and what characterizes it?

Back 736

Echovirus 16
fever followed by roseola-like rash

Front 737

What are human Parechoviruses 1 and 2, and what dz does parechovirus 1 cause?

Back 737

ex-enterovirus members of the picornavirus genus Parechovirus

Parechovirus 1 causes infantile diarrhea and resp. illness

Front 738

What are the 2 major groups of coxsackievirus and how many serotypes do each have?

Back 738

A (23 serotypes)
B (6 serotypes)

Front 739

What cells are used to culture poliovirus?

Back 739

human embryonic kidney or rhesus monkey kidney

Front 740

What numbers are assigned to unspecified enteroviruses?

Back 740

68-71

Front 741

Dz caused by Enterovirus 70

Back 741

acute hemorrhagic conjunctivitis (often in epidemics)

Front 742

Dz caused by Enterovirus 71

Back 742

hand-foot-and-mouth dz,
herpangia
encephalitis
acute flaccid paralysis (resembles poliomyetlitis)

Front 743

Which Coxsackie virus can be grown in cell culture?

Back 743

B

Front 744

The mouse injected with isolated virus from the patient demonstrates generalized myositis and flaccid paralysis from attack of striated muscle- what is the virus?

Back 744

Coxsackie A

Front 745

The mouse injected with isolated virus from the patient demonstrates focal myositis, spastic paralysis from encephalitis -what is the virus?

Back 745

Coxsackie B

Front 746

The mouse injected with isolated virus from the patient demonstrates myocarditis, pancreatic necrosis, and necrosis of brown fat - what is the virus?

Back 746

Coxsackie B

Front 747

Optimum rhinovirus temp

Back 747

33 degrees (nasal mucosa)

Front 748

Peaks seasons of rhinovirus

Back 748

spring and early fall

Front 749

What is the most common cause of the common cold?

Back 749

Rhinovirus

Front 750

How are rhinoviruses transmitted?

Back 750

aerosols or fomites

Front 751

what are fomites?

Back 751

objects that mediate transmission (door knobs, tissues, utensils)

Front 752

Which virus induces high levels of interferon?

Back 752

rhinovirus

Front 753

Which receptor mediates rhinovirus entry?

Back 753

ICAM-1 (member of Ig supergene family)

Front 754

How many rhinovirus serotypes are there that do NOT have cross-reactivity?

Back 754

More than 120

Front 755

Is Rhinovirus zoonotic?

Back 755

Not really, monkeys can be infected but don't show sx

Front 756

What cells are used to culture rhinovirus?

Back 756

embryonic cell cultures, cultures of human fetal trachea

Front 757

What host defenses act against rhinovirus infection?

Back 757

IgA gives short-lived protection, mostly likely by blocking binding of virions to cell's receptors

Front 758

Orthomyxoviruses:
+/- ss/ds RNA/DNA
icosehedral/helical
enveloped/naked
rep. in cytoplasm/nucleus

Back 758

segmented (8)
- ssRNA
helical
enveloped
rep. requires nucleus (steals 5' caps from host mRNA)

Front 759

What's special about Orthomyxoviruses' envelope?

Back 759

has surface glycoprotein spikes (HA, NA)

Front 760

Main structural protein/antigen of Influenza virus

Back 760

NP: nucleoprotein

Front 761

matrix proteins of influenza virus

Back 761

M1: membrane protein, functions in budding and assembly
M2: forms pH activated ion channels important in viral uncoating

Front 762

What do amantadine and rimantadine target?

Back 762

M2

Front 763

How are the matrix proteins of influenza virus created?

Back 763

alternative splicing

Front 764

which antigens of influenza virus elicit type-specific Abs? What function do they serve?

Back 764

NP
M1
(can be used diagnostically, but are not protective)

Front 765

what is hemagglutination (in the context of viruses with HA)?

Back 765

formation of a lattice of virus and RBCs seen when influenza virus in incubated with RBCs

Front 766

What is hemadsorption (in the context of viruses with HA)?

Back 766

binding of RBCs to the HA on infected cells,
used in dx

Front 767

Function of Hemagglutinin (HA)

Back 767

attachment to sialic acid residues and entry into host cells

Front 768

What accounts for influenza viruses' broad host range?

Back 768

HA binds to sialic acid, which are common on cell surfaces

Front 769

Which Abs are the most important for immunity vs. influenza?

Back 769

Anti-HA Ab (prevents infection)
Anti-NA Ab (prevents spread of infection)

Front 770

What is required after HA attaches to a host cell before the virus enters the cell?

Back 770

Cleavage of HA by host cell serine protease

Front 771

Describe the sialic acid binding site on HA and its significance

Back 771

very small part of protein
trimer of globular peptides each on its own stalk
allows HA to change antigenically under selective pressure from immune system while preserving a functional binding site

Front 772

functions of neuraminidase on influenza virus

Back 772

1) release virus from host cell (by hydrolyzing sialic acid residues on envelopes of progeny viruses)
2) hydrolyze mucoproteins in nasal secretions (help spread virus)

Front 773

How do orthomyxoviruses enter cells?

Back 773

HA binds sialic acid, virus in endocytosed as host serine protease cleaves HA.
endosome is acidified, prompting fusion of viral membrane with endosome membrane, releasing nucleocapsid into cytoplasm

Front 774

Why do Orthomyxoviruses need the host nucleus to replicate?

Back 774

to steal host mRNA's 5' caps

Front 775

How does Actinomycin D work and what principle does it demonstrate?

Back 775

binds DNA (blocking txn of DNA by RNA Pol)
-blocks influenza virus production b/c orthomyxovirus requires the host to supply 5' RNA cap

Front 776

Are different influenza types cross-reactive? Serologically or genotypically distinctive?

Back 776

Within a type (A, B or C),yes. but not between types
The three types are serologically and genotypically distinctive

Front 777

Which influenza antigens are subjected to more selective pressure, M and NP, or HA and NA?

Back 777

HA and NA because they are external

Front 778

Which type of Orthomyovirus must be subtyped further (based on its HA and NA)?

Back 778

Influenza virus A (because it has animal reservoirs in which it can undergo reassortment)

Front 779

Two types of antigenic variation

Back 779

antigenic drift
antigenic shift

Front 780

which type of influenza virus can undergo antigenic drift?

Back 780

All of them (A, B, C)

Front 781

which type of influenza virus can undergo antigenic shift?

Back 781

A

Front 782

What causes antigenic drift in influenza virus?

Back 782

minor changes in NA and HA due to missense mutations (change antigens but not function)

Front 783

What causes antigenic shift in influenza virus?

Back 783

introduction of one or more "new" RNA segments acquired through reassortment between animal and human viruses when co-infected inside a cell (often pigs capable of infection with human and avian strains)

Front 784

Which type of antigenic variation causes pandemics?

Back 784

Antigenic shift

Front 785

Which of the types of influenza virus has a more severe infection?

Back 785

A>B>C

Front 786

What is feared about avian flu (Influenza A H5N1)?

Back 786

widespread outbreaks in birds, has killed several people.
if a virus has both human and avian virus genes, it can cause worldwide pandemic (once it establishes the ability to transmit person-to-person)
-resistant to adamantanes

Front 787

Seasonal peaks of influenza

Back 787

winter months

Front 788

Extent and severity of influenza outbreaks depends on:

Back 788

prevalence of Abs to circulating virus
intrinsic virulence of virus (B less virulent than A, but B still can be fatal)

Front 789

Time course of influenza A outbreak

Back 789

begins abruptly (children with febrile respiratory illness)
peaks in 2-3 weeks (adults get influenza)
lasts total of 2-3 months

Front 790

typical attack rate of influenza

Back 790

10-20% of susceptible population during outbreak,
>50% of susceptible population during pandemics

Front 791

Influenza sx

Back 791

fever (febrile illness, all sx usually self-lmtd)
HA
sore throat/cough
nasal discharge
malaise
myalgias

Front 792

complications of influenza

Back 792

pneumonia,
bronchitis,
sinus/ear infections

Front 793

risk factors for complications from influenza (and therefore should get a flu shot)

Back 793

>65 yo (ppl >50 get shot)
chronic medical conditions (COPD, DM, cardiopulmonary dz)
very young children
pregnancy women

Front 794

How is influenza transmitted/acquired?

Back 794

airborne transmission, enters nasopharynx and infects ciliated mucosal epithelial cells of the resp. tract

Front 795

What do influenza-infected ppl's nasal/bronchial biopsies show?

Back 795

desquamation of ciliated columnar epithelial cells of the bronchi

Front 796

When do anti-NA and anti-HA Abs develop during an influenza infection?

Back 796

beginning of 2nd week

Front 797

What parts of human immune system are important defenses against influenza infection?

Back 797

neutralizing antibodies vs. NA and HA (prevent new infections)
cell-mediated immunity important for clearance of infection and recovery

Front 798

Influenza dx

Back 798

viral culture
PCR
DFA (direct fluorescent Ab)
enzyme immunoassay
retrospective: 4x increase in Ab titers demonstrated on HA-inhibition test

Front 799

Amantidine and rimantidine treat/prevent what dz?

Back 799

influenza type A

Front 800

Amantidine and rimantidine mechanism

Back 800

M2 blockers, can't acidify endosome so can't uncoat virus

Front 801

Zanamivir and oseltamivir treat/prevent what dz?

Back 801

Influenza type A or B

Front 802

zanamivir approved for treatment of influenza in which patients?

Back 802

over 7 yo

Front 803

oseltamivir approved for treatment and prophyllaxis of influenza in which patients?

Back 803

treatment: >18yo
prophyllaxis: >13yo

Front 804

Reye's syndrome sx

Back 804

lethargy/delirium/obtundation
seizures
resp. distress
10-30% mortality

Front 805

what causes Reye's syndrome?

Back 805

giving aspirin to children with viral infections

Front 806

What are the subfamilies of family paramyxoviridae?

Back 806

paramyxovirinae
pneumoviridae

Front 807

genera of subfamily paramyxovirinae

Back 807

paramyxovirus (parainfluenza 1-4)
rubulavirus (mumps)
morbillivirus (measles)
henipavirus (nipah and hendra virus)

Front 808

What are Nipah and Hendra viruses?

Back 808

paramyxoviruses capable of jumping species, causing severe/fatal dz in humans

Front 809

Natural reservoir of Nipah and Hendra virus

Back 809

Pteropus bats

Front 810

How are Nipah/Hendra virus acquired?

Back 810

close association with infected domestic animals

Front 811

Dz caused by Nipah virus

Back 811

encephalitis

Front 812

Nipah virus endemic areas

Back 812

Southeast Asia
Australia

Front 813

Dz caused by Hendra virus

Back 813

resp. illness with severe flu-like sx

Front 814

Genera of Paramyxoviridae subfamily pneumovirinae

Back 814

pneumovirus (RSV)
metapneumovirus (metapneumovirus)

Front 815

Paramyxoviridae:
+/- ss/ds RNA/DNA
icosahedral/helical
enveloped/naked
rep in cytoplasm/nucleus

Back 815

- ssRNA
helical
enveloped
rep. in cytoplasm (except measles)

Front 816

what is special about the envelope of paramyxoviridae?

Back 816

has surface glycoprotein spikes

Front 817

Which paramyxoviridae family member replicates in the nucleus?

Back 817

Measles

Front 818

Paramyxoviridae CPE

Back 818

syncytia formation (aka multinucleated giant cells, due to fusion at neutral pH)
eosinophilic cytoplasmic inclusion bodies

Front 819

CPE specific to measles

Back 819

nuclear inclusion bodies

Front 820

Fusion (when creating syncytia of paramyxoviridae) requires:

Back 820

cleavage of viral glycoprotein by host cell protease

Front 821

How are parainfluenza viruses transmitted?

Back 821

person to person via resp. secretions

Front 822

How is Mumps transmitted?

Back 822

person to person via resp. secretions

Front 823

What surface glycoproteins do paramyxovirus (parainfluenza) and rubulavirus (mumps) share?

Back 823

HN - combined hemagluttin and neuraminidase
F - fusion protein, mediates fusion of virus with host cell (F0 cleaved by host cell protease into F1 and F2)

Front 824

Which receptor do paramyxovirus and rubulavirus use to enter cells?

Back 824

sialic acid receptor

Front 825

Do paramyxoviruses and rubulaviruses exhibit hemagglutination or hemadsoprtion?

Back 825

Both

Front 826

Describe croup

Back 826

acute upper and lower resp. tract febrile illness in children
presents with "seal bark" stridor

Front 827

age group at highest risk for croup

Back 827

3 month-3 year olds

Front 828

what causes croup?

Back 828

parainfluenza viruses 1, 2, and 3

Front 829

when do epidemics of parainfluenza viruses occur?

Back 829

fall and spring

Front 830

what is the 2nd leading cause of lower resp. infections in infants?

Back 830

parainfluenza viruses

Front 831

What dz causes bronchiolitis?

Back 831

parainfluenza viruses

Front 832

what organs does mumps attack?

Back 832

parotid, pancreas, gonads

Front 833

Mumps sx

Back 833

salivary gland enlargement
fever
possibly orchitis (inflamm of testes),
meningitis (1/1000 mortality rate), or
deafness

Front 834

Important members of genus morbillivirus

Back 834

measles
canine distemper
Rinderpest

Front 835

How is measles (and all dz from genus morbillivirus) transmitted?

Back 835

person to person via resp. secretions

Front 836

Surface glycoproteins of genus morbillivirus and their function

Back 836

H - binds receptor and hemagglutinates
F - fuses with host cell

Front 837

Receptor for viruses of genus morbillivirus

Back 837

CD46 and CD150 (SLAM)

Front 838

Does measles infection involve an neuraminidase?

Back 838

No, the receptor is not sialic acid, so it is not needed

Front 839

How does F protein mediate entering of genus morbillivirus into host cell?

Back 839

F0 binds host cell,
host cell protease cleaves into F1 and F2

Front 840

How does rubeola spread through the body?

Back 840

rubeola = measles
local rep in nasal mucosa
moves to lymph nodes
viremia spreads infection throughout body (tho patient is asx until before rash)

Front 841

Measles sx

Back 841

conjunctivitis
dry cough
low grade fever
Koplik's spots
rash moving from face to trunk

Front 842

Can measles change antigenically?

Back 842

No, therefore it requires a large susceptible population to be maintained in nature

Front 843

Animal reservoirs of measles

Back 843

none

Front 844

how is measles rash described?

Back 844

morbilliform exanthem that moves from face to trunk

Front 845

What do you give to measles-infected children in developing countries and why?

Back 845

Vitamin A because it decreases morbidity and mortality

Front 846

Can you get measles repeatedly?

Back 846

No, natural infection confers life-long immunity, as does the live attenuated vaccine

Front 847

Measles complications

Back 847

acute post-infection encephalitis (some mortality)
pneumonia (less developed countries)
SSPE (subacute sclerosing panencephalitis)

Front 848

What is the most common cause of death due to measles in developed countries?

Back 848

encephalitis

Front 849

What is the most common cause of death due to measles in developing countries?

Back 849

pneumonia

Front 850

What was atypical measles?

Back 850

not seen anymore b/c associated with old (formalin-inactivated) vaccine.
high fever, edema of extremities, interstitial pulmonary infiltrates, vesicular rash

Front 851

What is modified measles?

Back 851

extremely mild form of measles in partially immune people
(seen in infants, or ppl receiving gamma globulin post-exposure).
prolonged incubation, variable sx

Front 852

What is SSPE?

Back 852

subacute sclerosing panencephalitis
caused by restricted viral replication in brain
latent for median of 7 years after measles infection
death within 6-12 months of onset

Front 853

Two major groups of RSV and what differentiates them

Back 853

RSV A and RSV B,
based on G glycoprotein

Front 854

How is Pneumovirus transmitted?

Back 854

fomites (major)
aerosol (minor)

Front 855

How long can RSV survive in the environment?

Back 855

7 hours

Front 856

How long after the illness is RSV shed?

Back 856

2-3 weeks

Front 857

Pneumovirus surface glycoproteins

Back 857

G - binds receptor
F - fusion of virus with host cell (F0 cleaved into F1+F2)

Front 858

Do pneumoviruses show hemagglutination or hemadsorption?

Back 858

No, no hemolysin activity either!

Front 859

What age group is hit hardest by RSV?

Back 859

infancy and early childhood

Front 860

What is the major cause of pneumonia and bronchiolitis in children <1 year?

Back 860

RSV (25-40% of all infected children, some require hospitalization)

Front 861

RSV sx in young children

Back 861

high fever, runny nose, severe cough, sometimes wheezing

Front 862

RSV sx in adults

Back 862

colds
elderly or compromised cardiac/pulm/immuno systems: pneumonia

Front 863

What is the most common cause of pediatric nosocomial infections?

Back 863

RSV

Front 864

Is RSV immunity protective?

Back 864

Only against severe infections, but repeat infections occur throughout life.
Anti-G and Anti-F Abs protect against lower resp. tract infections.
IgA Abs against URIs are short-lived

Front 865

Peak of RSV epidemics

Back 865

peak = winter (Feb. in SD)
last from late fall to early spring

Front 866

RSV dx

Back 866

gold standard: virus isolation in HEp-2 cells
most common: antigen detection assay

Front 867

RSV tx

Back 867

ribavirin (aerosol),
but drug is problematic with limited efficacy...

Front 868

Papovavirus:
+/- ss/ds RNA/DNA
icosahedral/helical
enveloped/naked
rep. in cytoplasm/nucleus

Back 868

circular dsDNA (+histones assoc. w/ viral capsid)
icosahedral
naked
rep. in nucleus

Front 869

2 genera of Papovaviruses

Back 869

Papillomaviruses
Polyomaviruses

Front 870

2 types of Papillomaviruses

Back 870

HPV-1 to HPV-100
others (in other animal species)

Front 871

3 types of Polyomaviruses

Back 871

JC and BK viruses
SV40
others (in animal species)

Front 872

Does papovavirus infection elicit protection from future infections?

Back 872

No, chronic/persistent infections

Front 873

How many distinct (<50% sequence homology) HPVs are there?

Back 873

more than 100

Front 874

Do papillomaviruses have broad or narrow host ranges?

Back 874

Narrow

Front 875

What kind of Abs (type specific or genus specific) are made against papillomaviruses?

Back 875

type specific (made against intact virion). virus must be denatured to expose group-specific antigens and elicit group-specific Abs

Front 876

How do Papillomaviruses make the 7 early and 2 late (capsid) genes?

Back 876

splicing

Front 877

What is an episome?

Back 877

genetic element that either exists free from cell genome, or integrated into host chromosome

Front 878

What are the important early genes of Papillomaviruses?

Back 878

E2 - supresses txn of:
E5, E6, E7 - influence transformation

Front 879

Can papillomaviruses be grown in cultures?

Back 879

No, they require terminally differentiated squamous epithelial cells (keratinocytes)

Front 880

What causes warts?

Back 880

HPV

Front 881

Why do warts recur after excision?

Back 881

The basal layer of cells also contain viral DNA and only express early HPV genes

Front 882

What is the hallmark CPE of productive HPV infection?

Back 882

Koilocytes: epithelial cell with shrunken, pyknotic nucleus in the middle of a large vacuole (produced from coalescence of smaller perinuclear vacuoles)

Front 883

How does HPV cause cervical cancer?

Back 883

intergrates into host cell chromosome, disrupting its own tumor suppressor (E2)

Front 884

Which HPV genes are responsible for cervical cancer?

Back 884

E2 suppresses E5, 6, 7
E6 binds p53 and accelerates its degradation (inhibiting apoptosis)
E7 bind RB, inactivating it and increasing DNA synthesis and mitosis

Front 885

Which HPV types are most associated with cervical cancer?

Back 885

HPV-16, 18, 31 and 45

Front 886

Are HPV-6 and 11 (genital wart types) oncogenic?

Back 886

Not really! (low oncogenic potential)

Front 887

How often is cervical cancer NOT caused by HPV?

Back 887

10%

Front 888

How is HPV transmitted?

Back 888

direct contact (venereal, autoinoculation)
indirect contact (pick up via cut on bottom of foot contacting virus left by a plantar wart)

Front 889

HPV tx

Back 889

physical/chemical destruction of wart

Front 890

HPV vaccines mech and types

Back 890

empty virus shells elicit neutralizing Abs against:
types 16, 18 (70% of cervical, anal, genital cancer)
types 6, 11 (90% genital warts, laryngeal papillomatosis)

Front 891

HPV dz

Back 891

common wart, plantar wars (benign squamous epithelial tumors)
laryngeal papillomatosis
epidermodysplasia verruciformis
condyloma acuminatum (genital warts)

Front 892

How is laryngeal papillomatosis transmitted?

Back 892

to baby via birth canal

Front 893

Laryngeal papillomatosis tx

Back 893

surgical removal of warts (clear airway)
interferon to prevent recurrence (though they recur after interferon stopped)

Front 894

Epidermodysplasia verruciformis genetics

Back 894

AR

Front 895

Epidermodysplasia verruciformis sx

Back 895

extensive chronic cutaneous HPV infection,
1/3 go on to malignant carcinomas, only on sun-exposed skin

Front 896

What HPV types most often cause epidermodysplasia verruciformis?

Back 896

5 and 8

Front 897

What is the most common sexually transmitted viral dz?

Back 897

condyloma acuminatum (genital warts)

Front 898

Are most genital wart-causing HPV infections mild or severe?

Back 898

Most asx and transient, but persistent infection with oncogenic HPV is a concern!

Front 899

How many of the DNA strands of papillomavirus are read (encode gene products)?

Back 899

One

Front 900

How many of the DNA strands of polyomavirus are read (encode gene products)?

Back 900

Two.
One contains early genes, the other late

Front 901

Polyomaviruses are resistant to ...

Back 901

formalin and heat

Front 902

How do polyomaviruses get the most out of their genome?

Back 902

RNA splicing, alternative reading frames to allow encoding of multiple products

Front 903

Which type of Papovavirus has enhancer elements?

Back 903

Polyomaviruses - impt. determinant of host range and tissue tropism

Front 904

Describe enhancer elements

Back 904

not gene- or promoter-specific
located up- or down-stream of the genes they affect
can be in any orientation
not transcribed into RNA (also don't code for proteins)
just bind host TFs

Front 905

How many capsid proteins and T antigens do polyomaviruses have?

Back 905

2 capsid proteins
2-3 T antigens

Front 906

What is the classic CPE of Polyomaviruses?

Back 906

perinuclear cytoplasmic vacuolation
formation of intranuclear inclusion bodies

Front 907

Do polyomaviruses cause tumors in their natural hosts?

Back 907

No (only early genes are expressed)

Front 908

What kind of infections do polyomaviruses cause in natural hosts?

Back 908

productive infections

Front 909

What kind of infections do polyomaviruses cause in hosts other than their natural host?

Back 909

abortive infections, transform (tumors)

Front 910

What virus causes PML (Progressive Multifocal Leukoencephalopathy)?

Back 910

JC virus

Front 911

PML sx

Back 911

ataxia
dementia
visual field defects
weakness of the extremities
speech disturbances
coma/death within 6 months of onset

Front 912

What type of cells do JC virus replicate in?

Back 912

primary human fetal glial cells

Front 913

How does JC virus relate to SV40 and BK virus?

Back 913

70% homology among them, but different enhancer element

Front 914

What % of children (10-14 yo) are infected by JC virus?

Back 914

40%

Front 915

What % of adults are infected by JC virus?

Back 915

80%

Front 916

How might JC virus be passed to a baby?

Back 916

through the urine - JC virus can infect and establish latency in the kidney, and be shed in urine during acute infection and following reactivation from latency

Front 917

What immunosuppressed states put ppl at risk for PML?

Back 917

AIDS
organ transplantation
pregnancy

Front 918

PML mech

Back 918

subacute, progressive demyelinating dz in patient with impaired cellular immunity
lytic infection of oligodendrocytes (which produce myelin) and transforms astrocytes

Front 919

Is PML most often caused by new JC virus infection, or reactivation of old JC virus?

Back 919

reactivation

Front 920

Which virus, BK or JC, infects children earlier?

Back 920

BK

Front 921

Which virus, BK or JC, is associated with viruria?

Back 921

Both

Front 922

What cell types does BK replicate in?

Back 922

human embryonic kidney cells, fetal fibroblasts, fetal brain cells, newborn urinary epithelial cells

Front 923

Which virus, BK or JC, has more restrictive tissue tropism?

Back 923

JC

Front 924

What dz does BK virus cause?

Back 924

nothing in normal host
in immunocompromised: possibly nephritis in a transplanted kidney (leading to renal failure)

Front 925

Dz caused by adenovirus

Back 925

asx (50%)
acute resp. tract infections
conjunctivitis
hemorrhagic cystitis
gastroenteritis

Front 926

Adenovirus:
+/- ss/ds RNA/DNA
icosahedral/helical
enveloped/naked
rep. in cytoplasm/nucleus

Back 926

dsDNA
icosahedral
naked
rep. in nucleus

Front 927

the icosahedral capsid of adenovirus is composed of:

Back 927

hexons, pentons and fibers

Front 928

what is the conformation of the hexons, pentons and fibers in adenovirus capsid?

Back 928

protruding fibers (containing type-specific viral attachment proteins used to attach to host cells) at vertices of pentons.
group-specific antigens located on the hexon and penton bases

Front 929

what is attached to the 5' end of adenovirus' genome?

Back 929

pTp (terminal protein)

Front 930

neutralizing Abs are made to which adenovirus Ags?

Back 930

hexon and fiber Ags

Front 931

How are adenoviruses divide into subgenera?

Back 931

A-F,
based on various biochem and serological criteria

Front 932

what types of infection is adenovirus capable of?

Back 932

lytic infection, chronic infection in human lymphoid cells, oncogenic transformation in certain animal cells

Front 933

How long does it take adenovirus to replicate in tissue culture?

Back 933

24-30 hours (fast!)

Front 934

How does adenovirus adhere to a host cell?

Back 934

CAR receptor binds its fiber, causing endocytosis

Front 935

CPE of adenovirus

Back 935

grape-like clustering of cells,
basophilic inclusion bodies
(host cell lyses and releases virions)

Front 936

What transcribes the early RNAs of adenovirus?

Back 936

cellular RNA polymerase

Front 937

How does adenovirus replicate its DNA?

Back 937

uses viral proteins as primer (pTp),
viral DNA polymerase,
72kD DNA-binding protein,
plus cellular factors

Front 938

Functions of adenovirus E1a

Back 938

codes for 2 alternatively spliced proteins with multiple functions
-turns on other early genes and late genes (major transactivator)
-binds RB
-inhibits activation of interferon response elements

Front 939

Functions of adenovirus E1b

Back 939

blocks host mRNA transport to cytoplasm
binds p53, preventing apoptosis
protects cells from lysis with TNF

Front 940

Functions of adenovirus E2

Back 940

encodes DNA replication proteins (DNA polymerase, pTp, 72kD binding protein)

Front 941

Functions of adenovirus E3

Back 941

dispensable for growth in tissue culture
helps virus escape immune surveillance by complexing with MHCI and preventing it from leaving ER
protects cell from lysis by TNFalpha

Front 942

Functions of adenovirus E4

Back 942

blocks transport of host cell RNA
encodes late genes (e.g. capsid proteins) - made after virus DNA replicated
one promoter, leading to long txn unit that is alternatively spliced into 5 families of RNA (all with polyadenylated 3' end)

Front 943

Functions of adenovirus VA (VA1 and VA2)

Back 943

transcribed by eukaryotic RNA Pol III
not translated but allow viral mRNA translation late in infection,
VA1 binds/inactivates a dsRNA protein kinase that usually shuts down translation when dsRNA is around
(the same kinase induced by interferon)

Front 944

Dzs caused by adenovirus in neonates

Back 944

pneumonia

Front 945

Dzs caused by adenovirus in infants

Back 945

coryza
pharyngitis

Front 946

Dzs caused by adenovirus in children

Back 946

colds (URIs)
pharyngoconjunctival fever
hemorrhagic cystitis
diarrhea
intussusception

Front 947

Dzs caused by adenovirus in young adults

Back 947

acute resp. dz
pneumonia

Front 948

Dzs caused by adenovirus in adults

Back 948

epidemic ketatoconjunctivitis

Front 949

Dzs caused by adenovirus in immunocompromised

Back 949

pneumonia with dissemination
UTI
CNS dz (incl. meningoencephalitis)

Front 950

What is pharyngoconjunctival fever?

Back 950

conjunctivitis with or without pharyngitis, rhinitis, cervical adenitis, fever.
aka summer camp illness, swimming pool conjunctivitis. caused by adenovirus in children

Front 951

What is hemorrhagic cystitis?

Back 951

gross hematuria for approx. 3 days, microscopic hematuria, dysuria and frequency for several more days.
boys>girls.
maybe caused by adenovirus in children

Front 952

What is epidemic keratoconjunctivitis?

Back 952

conjunctivitis of insidious onset, frequently bilateral, preauricular adenopathy common.
keratitis begins as conjunctivitis wanes, and can go on for months.
caused by adenovirus in adults

Front 953

Adenovirus dx

Back 953

isolated virus
EIA (enzyme immunoassay - monoclonal Ab to hexon epitope, then type-specific monoclonal Ab used to ID specific type of adenovirus)
PCR
Restriction Enzyme analysis

Front 954

Adenovirus tx

Back 954

none necessary: self-lmtd dz, death is rare

Front 955

Adenovirus vaccine

Back 955

oral live, unattenuated. inoculated into GI tract (does not lead to dz, that's only if inoculated into resp. tract).
used for military only

Front 956

What is the largest and most complex virus?

Back 956

Poxviridae

Front 957

How many pox viruses infect humans?

Back 957

9:
variola (small pox)
monkeypox (zoonotic, makes rash)
cowpox
vaccinia (avirulent, current smallpox vaccine)
orf virus (sheet and goat pox)
molluscum contagiosum (chronic localized flesh-colored dome papules on skin, spread skin to skin)

Front 958

when was smallpox eradicated?

Back 958

1979

Front 959

What feaures of smallpox allowed its eradication?

Back 959

obligate human
hit and run (no latency, immunity is lifelong)
all infections cause dz (easy to ID)
vaccine stable and easy to transport
time, money and effort were invested!

Front 960

Poxvirus:
+/- ss/ds RNA/DNA
icosahedral/helical
enveloped/naked
rep. in cytoplasm/nucleus

Back 960

dsDNA
neither icosahedral nor helical (large and brick-shaped)
enveloped
rep. in cytoplasm

Front 961

what shape is the core of poxvirus and what is it composed of?

Back 961

dumbbell, composed of nucleoprotein

Front 962

What is at the end of poxvirus genome?

Back 962

haripin loops

Front 963

what happens when poxvirus DNA denatured?

Back 963

becomes single-stranded closed circle

Front 964

How was smallpox spread?

Back 964

inhalation

Front 965

Where does smallpox multiply?

Back 965

probably within macrophages, which then enter the bloodstream and carry virus with them to lymphoid tissue

Front 966

What type of vesicles form on the skin of smallpox patients?

Back 966

intraepidermal, leading to extensive scarring (pox marks)

Front 967

What host defense are elicited by smallpox infection?

Back 967

cytotoxic T cells
neutralizing Abs
IFN production
(restrict replication, lead to lasting immunity)

Front 968

General characteristics of herpesviridae

Back 968

large and complex
encode many enzymes, incl. nucleic acid synth and metab

Front 969

Herpesviridae:
+/- ss/ds RNA/DNA
icosahedral/helical
enveloped/naked
rep. in cytoplasm/nuc

Back 969

dsDNA
icosahedral
enveloped
rep. in nucleus

Front 970

What do herpesviridae genomes consist of?

Back 970

UL and US regions bounded by inverted repeats (IR)
exact arrangement differs in different Herpesviruses

Front 971

What is the amorphous protein-filled region between the envelope and the capsid called?

Back 971

tegument

Front 972

What antigens do Herpesviridae share?

Back 972

None, no common family antigens

Front 973

What kind of infection can all members of the Herpesvirus family cause?

Back 973

latent

Front 974

What is the Herpes subfamily division based on?

Back 974

biological properties and/or genome organization and DNA sequence homology

Front 975

Which viruses are included in the alpha herpesvirus subfamily?

Back 975

HSV-1, HSV-2, VZV

Front 976

Which viruses are included in the beta herpesvirus subfamily?

Back 976

CMV, roseolaviruses (HHV-6, HHV-8)

Front 977

Which viruses are included in the gamma herpesvirus subfamily?

Back 977

EBV, HHV-8

Front 978

What host range do alpha, beta and gamma herpesviruses have?

Back 978

alpha: broad
beta: restricted
gamma: very restricted (T or B lymphs)

Front 979

Which has a longer replication cycle, alpha or beta herpesviruses?

Back 979

beta has a long rep. cycle, while alpha has a short one

Front 980

Alpha herpesvirus CPE

Back 980

Cowdry type A eosinophilic intranuclear inclusion bodies
multinuclated giant cells
lead to cell death

Front 981

Beta herpesvirus CPE

Back 981

cytomegalia (cell enlargement)

Front 982

Where do alpha, beta, and gamma herpesviruses establish latent infections?

Back 982

alpha: sensory neurons
beta: secretory glands, reticulendothelial cells, kidney, etc.
gamma: lymphoid tissue

Front 983

what kind of infections do beta herpesviruses cause in cell culture?

Back 983

slowly progressive infections

Front 984

What is special about the HSV envelope, and how is it acquired?

Back 984

radially-oriented glycoprotein spikes of 11 different types.
acquired by budding through inner lamella of nuclear membrane, exits cell using Golgi apparatus/transport vesicles

Front 985

What composes the icosahedral HSV capsid?

Back 985

162 hexagonal capsomers, each with a small central hole

Front 986

What does the tegument of HSV contain?

Back 986

viral proteins:
-alpha TIF (aka VP16): transactivator of alpha genes
-viral host shutoff (VHS) protein: promotes degradation of host mRNAs
-A phosphoprotein: allows viral DNA to circularize

Front 987

Which viruses that infect humans have the largest genomes?

Back 987

#1 pox
#2 hsv

Front 988

What is the implications for HSV of the IR sequences?

Back 988

since they flank the UL and US sequences, they permit these sequences to invert during replication, forming 4 isomers in equimolar amounts

Front 989

How does HSV replicate its DNA?

Back 989

circularizes its genome and uses rolling circle replication

Front 990

Do latently infected cells (of HSV) die?

Back 990

No, though productively infected cells do

Front 991

What is Herpesvirus simiae?

Back 991

Herpes B virus, monkey's equivalent to HSV
causes meningoencephalitis with 95% mortality when it infects humans
acquired by monkey bites

Front 992

How long is HSV incubation period?

Back 992

short (2-7 days)

Front 993

Where does primary HSV infection occur?

Back 993

at portal of entry

Front 994

Factors inducing HSV reactivation

Back 994

fever, sunlight, menses, probably stress

Front 995

is it possible to spread HSV without knowing it?

Back 995

Yes, 80-90% of primary infections are asx, as are most reactivations.

Front 996

HSV dx

Back 996

Tzanck smear (same as VZV)

Front 997

How is a Tzanck smear performed?

Back 997

scrape cells from base of vesicular lesion, stain with Giemsa, Papanicoleau, or another stain

Front 998

Host defenses against HSV

Back 998

cornified epithelium
NK cells
cellular immunity (if T-lymphocyte fcn is impaired, dz is more severe)

Front 999

How does HSV enter a host cell?

Back 999

HSV's gB and gC attach to heparin sulfate proteoglycans, then gD binds another receptor, leading to fusion of viral envelope and host cell membrane at neutral pH
other (yet-to-be-identified) glycoproteins are required for entry into polarized cells

Front 1000

How do HSV nucleocapsids enter the host nucleus?

Back 1000

Nuclear pores

Front 1001

What transcribes HSV alpha (immediately early) and beta (early) genes?

Back 1001

host cell RNA Pol II

Front 1002

which tegument protein transactivates HSV alpha genes?

Back 1002

VP16 (alpha-TIF)

Front 1003

How many HSV alpha (immediately early) genes are there?

Back 1003

5
alpha-0, 4, 22, 27, 47.
(gene products have same numbers with ICP prefix)

Front 1004

HSV - Function of ICP0

Back 1004

transactivates promoters and enhances ICP4 function

Front 1005

HSV - Function of ICP4

Back 1005

required for expression of late (gamma) genes

Front 1006

HSV - Function of ICP27

Back 1006

regulates many HSV genes, required for the transition between beta and gamma gene expression

Front 1007

HSV - Function of ICP47

Back 1007

blocks presentation of HSV peptides by MHC I
(prevents the recognition and lysis of HSV infected cells by CD8 cells)

Front 1008

What functions do HSV beta (early) gene products do?

Back 1008

viral ribonucleotide reductase
major DNA binding protein
thymidine kinase
DNA polymerase
topoisomerase
helicase

Front 1009

Can HSV beta genes be expressed in the absence of alpha genes?

Back 1009

No

Front 1010

What are the gene products of HSV gamma (late) genes?

Back 1010

VP16 (aka alpha TIF) - packaged in tegument, turns on alpha gene txn
envelope glycoproteins and capsid proteins

Front 1011

What two times are HSV gamma (late) genes made?

Back 1011

gamma-1: before viral DNA replication (VP16, VHSP gB, gD)
gamma-2: capsid proteins

Front 1012

Which HSV membranes do not receive glycoproteins?

Back 1012

mitochondrial membranes
all other cell membranes have viral glycoproteins inserted in them

Front 1013

Def'n of latency

Back 1013

absence of infectious virus but presence of cells with the capacity to produce it

Front 1014

Model of HSV latency

Back 1014

HSV escapes immune system by traveling up axons of sensory neurons to cell bodies in sensory ganglia, but lose virion transactivators during the trip, such that the infection is latent and no HSV proteins are synthesized nor viral mRNA transcribed.

Front 1015

Does HSV reactivation tend to be more or less severe than primary infection?

Back 1015

Less severe, since the body has humor and cellular immunity

Front 1016

What is LAT, and what is its proposed function?

Back 1016

It is an antisense RNA downstream/overlapping HSV alpha-0 ORF.
It is found in low quantities during lytic cycle, but very high quantities in latent infection, suggesting it binds alpha-0 region and prevents txn

Front 1017

What is the evidence that HSV-1 and HSV-2 are closely related?

Back 1017

share >50% genes, in same order
recombinants are viable
cross-reactive immunity

Front 1018

How does HSV-1 dz distribution differ from HSV-2 dz distribution?

Back 1018

HSV-1 transmitted by oral secretions, most infections affect oropharynx, and reactivates more frequently from oropharynx infections (trigeminal ganglion)
HSV-2 transmitted by sexual contact, and reactivates more frequently from genital infection (Sacral ganglia)

Front 1019

Dz caused by HSV-1 and 2

Back 1019

acute gingivostomatitis (children)
- reactivation: asx shedding of HSV in saliva, herpes labialis
pharyngotonsilitis (in upper class adults not exposed as children, looks like Strep A)
herpetic whitlow
keratoconjunctivitis, keratitis
genital herpes
cutaneous
herpes encephalitis- 70% untreated mortality
herpes gladiatorum

Front 1020

Describe gingivostomatitis

Back 1020

caused by HSV-1 in children
vesicles and painful ulcers
overgrowth of oral anaerobes b/c of decreased swallowing

Front 1021

Describe herpetic whitlow

Back 1021

finger infection often caused by autoinoculation (thumb sucking/finger chewing while orally infected)

Front 1022

Implications of HSV keratoconjunctivitis/keratitis

Back 1022

can result in corneal inflammation and scarring--> blindness

Front 1023

What is the leading cause of sporadic necrotizing encephalitis in the US and Europe?

Back 1023

herpes encephalitis

Front 1024

Describe herpes gladiatorium

Back 1024

skin infection in wrestlers, spread by direct contact with a person who is shedding virus

Front 1025

Differences between VZV and HSV

Back 1025

-number of serotypes (1 vs 2)
-%GC (46% vs. 68%)
host range (narrow vs. broad)
cell free virus in tissue culture (HSV only)
Acyclovir sensitivity (some vs. a lot)
incubation period (14 days vs 2-7days)
transmission (resp. vs direct contact)
%symptomatic: 95% vs 25%
reactivation dz location (dermatomal vs. focal w/in dermatome)
prodrome (long, severe vs. short, mild)
postherpetic neuralgia (common only with VZV)
frequency of symptomatic recurrence (high in HSV)
asx virus shedding (HSV)
increase in Ab titer upon recurrence (VZV)
risk of recurrence vs. age (increases vs. decreases)

Front 1026

VZV Tx

Back 1026

prevention: live attenuated vaccine for all children >12 months
VZV Ab or even vaccine early after exposure
Acyclovir w/in 24 hours of rash onset (for ppl with chronic skin/lung dz, on steroids, or >13 yo)

Front 1027

HHV-6 and HHV-7 show cell tropism for what kind of cells?

Back 1027

CD4 T lymphocytes

Front 1028

What dz can HHV-6 (or sometimes HHV-7) cause?

Back 1028

roseola infantum (aka exanthem subitum)

Front 1029

Roseola infantum/ exanthem subitum sx

Back 1029

high fever
maculopapular rash resolving uneventfully in hours/days
note: 80-100% adults seropositive, shed HHV-6 in saliva

Front 1030

What cancers are HHV-8 associated with?

Back 1030

Kaposi's sarcoma,
body cavity lymphoma

all in immunosuppressed ppl (HIV, renal transplant)

Front 1031

From where does CMV derive its envelope?

Back 1031

nuclear membrane

Front 1032

How can you divide CMV into strains?

Back 1032

restriction digests of genome

Front 1033

site of CMV latency

Back 1033

bone marrow

Front 1034

What cells does CMV infect in vivo?

Back 1034

monocytes, macrophages, PMNs, endothelial cells and sinusoidal lining cells

Front 1035

What cells grow CMV in culture?

Back 1035

human fibroblasts

Front 1036

Does CMV kill infected cells?

Back 1036

Yes

Front 1037

Where is CMV endemic?

Back 1037

Everywhere (ubiquitous)
but more widespread in developing countries and under lower socioeconomic conditions

Front 1038

Who is at particular risk for CMV and its implications?

Back 1038

Pregnant female daycare workers (may give child generalized infection - hsm, hearing loss, vision impairment, retardation, death)

Front 1039

CMV transmission

Back 1039

body secretions (blood, saliva, breast milk, urine),
sexual contact
organ transplantation
transplacental

Front 1040

Are people usually infected with multiple CMV strains?

Back 1040

no, normally just one, except if they're immunocompromised

Front 1041

Severe CMV presents in:

Back 1041

immunocompromised ppl
fetuses infected transplacentally

Front 1042

Dz caused by CMV

Back 1042

asx
mono-like syndrome ("heterophile negative mononucleosis," fever, mild hepatitis)
pneumonia (esp. transplant pt.s)
retinitis (esp. AIDS)
colitis
esophagitis
encephalitis (only AIDS)

Front 1043

Babies infected with CMV in utero but asx at birth...

Back 1043

5-10% go on to have some sort of hearing loss, chorioretinitis or mental retardation

Front 1044

How long does it take to culture CMV?

Back 1044

3-6 weeks

Front 1045

CMV Dx

Back 1045

culture
ELISA (but this requires host response)
shell vial technique detects immediate early and early genes, beware of FNs
PCR of plasma! or PBMC (peripheral blood mononuclear cells)
CMV Ag detection

Front 1046

Most common means of CMV Dx

Back 1046

PCR of plasma

Front 1047

CMV strategies to evade immune detection

Back 1047

downregulate MHC I (retain in ER, degrade heavy chains in cytosol, block peptide transporter req'd for assembly)
downregulate MHCII (HLA-Dra and HLA-Dma degraded)

Front 1048

CMV tx

Back 1048

ganciclovir
foscarnet
cidofovir
(all act on DNA Pol of CMV)
Note: ganciclovir must be phosphorylated by viral kinase encoded in UL97 CMV region

Front 1049

Host defense against CMV infection

Back 1049

humoral (IgM and IgG) and CMI
CMI critical for recovery from infection

Front 1050

From where does EBV acquire its envelope?

Back 1050

nuclear membrane

Front 1051

what is special about EBV's genome

Back 1051

It is divided into UL and US sequences and has tandomly reiterated terminal direct repeats and tandomly reiterated internal direct repeats

Front 1052

How many EBV strains infect humans, and how do these strains differ?

Back 1052

2
differ in sequence of viral genes expressed in latent infection
differ in abillity to transform B cells
no clinical difference

Front 1053

What types of cells does EBV infect?

Back 1053

B lymphocytes and nasopharyngeal epithelial cells

Front 1054

Where is EBV latency established?

Back 1054

B lymphocytes

Front 1055

Can EBV immortalize cells?

Back 1055

Yes, lymphoid ones

Front 1056

Which EBV membrane glycoproteins allow entry into the host cell?

Back 1056

gp350 binds CD21 on B cell
gH, gL and gp42 complex, and gp42 binds HLA-DR to allow penetration of cell membrane

Front 1057

What population is intrinsically immune to EBV?

Back 1057

Patients with X-linked agammaglobulinemia (lack mature B cells)

Front 1058

What EBV genes are expressed during latency?

Back 1058

Different genes in different condtions, but at least 10 possible genes:
2 RNAs (EBER-1, EBER-2),
6 nuclear proteins (EBNA-1, 2, 3A, 3B, 3C, LP)
and 3 membrane proteins (LMP-1, LMP-2A, LMP-2B)

Front 1059

What dz and latency genes is type 1 EBV latency associated with?

Back 1059

Burkitt's lymphoma,
only EBER-1, 2, and EBNA-1 are expressed

Front 1060

What dz and latency genes is type 2 EBV latency associated with?

Back 1060

nasal pharyngeal carcinoma,
only EBER-1, 2, EBNA-1 and LMP are expressed

Front 1061

What dz and latency genes is type 3 EBV latency associated with?

Back 1061

noncancerous cells
At least 10 genes are expressed

Front 1062

Function of EBNA-1 (EBV latency gene)

Back 1062

maintain EBV episome

Front 1063

Function of EBNA-2 (EBV latency gene)

Back 1063

upregulates the expression of LMP-1 and 2

Front 1064

Function of EBNA-3 (EBV latency gene)

Back 1064

a set of 3 proteins (A, B,C)
A inhibits EBNA-2's upregulation of LMP-2
B and C upregulate expression of selective B cell proteins, leading to B cell proliferation

Front 1065

Function of BARF-1 and BCRF-1 (EBV latency genes)

Back 1065

block the ability of interferon to inhibit growth of EBV transformed cells

Front 1066

Function of BHRF-1 and LMP-1 (EBV latency genes)

Back 1066

inhibit apoptosis

Front 1067

What % of adults have Abs to EBV?

Back 1067

90-95%

Front 1068

EBV transmission

Back 1068

mostly saliva (persists in oropharynx for 18 months after mono)

Front 1069

EBV dz

Back 1069

asx
minor resp. infection (infants and young children)
infectious mononucleosis

Front 1070

Infectious mononucleosis sx

Back 1070

fever
lymphadenopathy
pharyngitis
splenomegaly
jaundice, hepatomegaly, rash maybe

Front 1071

complications of mono

Back 1071

splenic rupture, hepatitis, cardiac and pulmonary problems

Front 1072

What virus can kill or cause B cell lymphomas in X-linked lymphoproliferative dz patients?

Back 1072

EBV
since X-linked lymphoprolif. dz is caused by absence of SAP (SLAM-associated protein), normal T and B cell interaction is impaired, leading to unregulated growth of EBV-infected B cells

Front 1073

What malignancies can occur months to years after EBV infection?

Back 1073

Burkitt's lymphoma,
nasopharyngeal carcinoma (esp. in South china),
Hodgkin's dz

Front 1074

What dz can EBV cause in immunosuppressed patients?

Back 1074

oral hair leukoplakia
lymphoid interstitial pneumonitis
non-Hodgkin's lymphoma

Front 1075

Describe Burkitt's lymphoma

Back 1075

high-grade malignant lymphoma of B cells,
in central Africa, assoc. with EBV and P. falciparum malaria, usually present in jaw.
In US, present as abdominal tumors, less assoc. with EBV
translocation 8: 14, 22, or 2 moves c-myc oncogene near Ig heavy or light chain, leading to abnormal regulation of c-myc gene (when expressed, increases tumorigenicity)

Front 1076

Host defense against EBV

Back 1076

humoral (IgM and IgG) and CMI
CMI critical for recovery from infection

Note: EBV depresses non-EBV specific CMI (reverses CD4+/CD8+ ratio for more than 3 months)

Front 1077

Mono dx

Back 1077

atypical lymphs (though also present in other conditions)
Monospot (heterophile test)
EBV-specific Abs

Front 1078

Morphology of atypical lymphocytes

Back 1078

larger (more cytoplasm), have nucleoli in their nuclei

cytoplasm tends to be indented by surrounding RBCs

Front 1079

Dzs that show atypical lymphocytes

Back 1079

EBV
Toxoplasmosis
Rubella
viral hepatitis
mumps
drug rxns

Front 1080

Which dx test is most sensitive and specific for EBV?

Back 1080

EBV-specific Ab test

(also more expensive)

Front 1081

When is a monospot most likely to be positive?

Back 1081

2-3 weeks after onset of illness (peak of heterophile Abs)

Front 1082

where are hookworm infections found? where does necator americanus predominate?

Back 1082

worldwide, but esp. in moist, warm climates.
N. americanus predominates in the Americas and Australia (ex. Southeast US)

Front 1083

what form of hookworm is infectious?

Back 1083

filariform larva

Front 1084

What is the most common symptom of hookworm infection?

Back 1084

iron deficiency anemia (caused by blood loss at site of intestinal attachment)

Front 1085

Hookworm sx

Back 1085

Iron deficiency anemia
"ground itch" - local skin manifestations (during larvae penetration)
respiratory symptoms (during pulmonary migration of larvae)

Front 1086

Hookworm dx

Back 1086

eggs in stool

Front 1087

Describe hookworm life cycle

Back 1087

eggs in stool, hatch into larvae in 1-2 days of warm, moist, shaded soil.
after 5-10 days (2 molts), become filariform infective larvae (survive 3-4 weeks), penetrate skin
carried in veins to heart and lungs, penetrate pulmonary alveoli, ascend bronchial tree and swallowed
reside and mature in small intestine for 1-2 years

Front 1088

What are diagnostic characteristics of hookworm eggs?

Back 1088

ellipsoidal shape and thin shell

Front 1089

Where is Strongyloides stercoralis found?

Back 1089

subtropical and tropical areas,
very low frequency in Southeastern US

Front 1090

How does Strongyloides' life cycle differ from other nematodes?

Back 1090

Can be free-living adult worms in the environment, and can also autoinfect by larvae penetrating perianal skin or interstinal mucosa

Front 1091

Strongyloides dx

Back 1091

larvae in feces

Front 1092

Strongyloides sx

Back 1092

asx
GI symptoms (ab pain, diarrhea)
pulmonary symptoms (during migration through lungs)
"creeping eruption" on back from autoinfection

Front 1093

How long can Strongyloides infections persist in a host?

Back 1093

40 years b/c capable of autoinfection

Front 1094

Stongyloides hyperinfection sx

Back 1094

ab pain
distension
shock
pulmonary complications
neurological complications
septicemia
potentially fatal!

Front 1095

What happens when you treat an immunosuppressed person who is hyperinfected with Strongyloides with steroids or chemo?

Back 1095

rapid dissemination of the organism through the body!
life-threateining!

Front 1096

Strongyloides tx

Back 1096

ivermectin
thiabendazole (alternative)

Front 1097

What is whipworm?

Back 1097

Trichuris trichiura

Front 1098

Where is Trichuris trichiura found?

Back 1098

worldwide, esp. tropical climates with poor sanitation (fecal/oral transmission)

Front 1099

How is trichuris trichiura transmitted/acquired?

Back 1099

fecal/oral - unembryonated eggs passed in feces, embryonated eggs are ingested

Front 1100

Does Trichuris trichiura cause eosinophilia?

Back 1100

No

Front 1101

Where inside the body do adult Trichuris trichiura reside?

Back 1101

large intestine

Front 1102

Trichuris trichiura dx

Back 1102

unembryonated eggs in feces

Front 1103

Trichuris trichiura sx

Back 1103

asx
heavy infection in undernourished children, cause chronic bloody diarrhea and rectal prolapse

Front 1104

How long can Trichuris trichiura survive in the host?

Back 1104

up to 6 years, avg. 3 years

Front 1105

How long does it take Trichuris trichiura eggs to become infective?

Back 1105

15 to 30 days in the soil

Front 1106

How long after the adult Trichuris worms are fixed in the colon do the females begin to lay eggs?

Back 1106

60-70 days, shedding 3,000 to 20,000 eggs/day!

Front 1107

Lifespan of adult Trichuris worm

Back 1107

1 year

Front 1108

What is the pinworm?

Back 1108

Enterobius vermicularis

Front 1109

What is the most common nematode infection in the US?

Back 1109

Enterobius vermicularis (pinworm)

Front 1110

Where is Enterobius found?

Back 1110

worldwide, just as prevalent in developed and developing countries.
more frequent in children

Front 1111

Is Enterobius vermicularis zoonotic?

Back 1111

No, obligate human

Front 1112

Does enterobius cause eosinophilia?

Back 1112

No

Front 1113

Enterobius dx

Back 1113

Scotch tape test (eggs collected from perianal area)

Front 1114

Enterobius sx

Back 1114

asx
perianal itching (can lead to excoriations and bacterial superinfection)
very occasionally appendicitis or salpingitis (due to migration)

Front 1115

How long does it take Enterobius to become infectious?

Back 1115

4-6 hours

Front 1116

Describe Enterobius life cycle

Back 1116

eggs deposited on perianal folds, autoinfection when eggs transferred from itching butt to eating, or via contaminated environmental surfaces.
Adults establish in the colon within 1 month, and nocturnally migrate to perianus and lay eggs.

Front 1117

Where in the host do adult Enterobius worms establish themselves?

Back 1117

Colon

Front 1118

Life span of adult Enterobius

Back 1118

2 months

Front 1119

Is Anisakis zoonotic?

Back 1119

Yes, larvae infect fish (herring, mackerel)

Front 1120

What temperatures kill the Ansakis in fish?

Back 1120

heat to 60 degrees, freeze to -20 degrees
FOR MORE THAN 24 hours

Front 1121

Ansakis sx

Back 1121

severe epigastric pain
vomiting

Front 1122

Ansakis tx

Back 1122

surgically remove worms

Front 1123

How are Ansakis species worms acquired?

Back 1123

eating undercooked seafood

Front 1124

Ansakis species reside in the stomach of what?

Back 1124

Marine mammals

Front 1125

What stage are the Ansakis larvae we ingest when eating raw fish?

Back 1125

3rd stage
1st stage form in embryonated eggs in the water of marine mammal feces,
2nd stage are free-swimming and are ingested by crustaceans

Front 1126

Factors to consider when choosing a schizonticide for malaria treatment

Back 1126

expected resistance pattern of organism
severity of infection
patient's background immune status

Front 1127

Which antimalarial drug acts on all stages of life cycle?

Back 1127

none

Front 1128

What does chloroquine phosphate treat?

Back 1128

Any malaria type except resistant P. falciparum

Front 1129

Mech of chloroquine phosphate

Back 1129

inhibit heme polymerase activity in intraerythrocytic form,
accumulates free heme (toxic to parasites)
inhibits release and action of TNF-alpha

Front 1130

Probable mech of resistance to chloroquine phosphate

Back 1130

reduced uptake or rapid excretion
(resistance present in P. falciparum and Asian P. vivax)

Front 1131

Chloroquine phosphate admin

Back 1131

PO

Front 1132

Primaquine phosphate admin

Back 1132

PO

Front 1133

What does primaquine phosphate treat?

Back 1133

tissue forms of P. vivax and T. ovale

Front 1134

Mech of primaquine phosphate

Back 1134

kills intrahepatic form, prevents dev of erythrocytic forms that are responsible for relapses
(also kills gametocytes)

Front 1135

Major side effects of primaquine phosphate

Back 1135

hemolytic anemia (Glucose-6-phosphate def)

Front 1136

Quinine gluconate admin

Back 1136

IV or parenteral

Front 1137

Quinidine sulfate admin

Back 1137

PO

Front 1138

Quinidine sulfate treats

Back 1138

chloroquine-resistant P. falciparum

Front 1139

Quinine gluconate treats

Back 1139

life-threatening chloroquine-resistant P. falciparum malaria

Front 1140

Quindine gluconate side effects

Back 1140

4x as cardiotoxic as quinine

Front 1141

Quinidine mech

Back 1141

inhibit heme polymerase of Plasmodium

Front 1142

Which drugs are considered Quinolones?

Back 1142

chloroquine
primaquine
mefloquine
quinine
quinidine

Front 1143

Which antiparasitic drugs inhibit folate metabolism?

Back 1143

pyrimethamine
Fansidar
sulfonamides
proguanil

Front 1144

Pyrimethamine treats

Back 1144

chloroquine-resistant P. falciparum malaria (in conjunction with quinine and sulfadoxine)
toxoplasmosis (treatment and prophyllaxis)

Front 1145

What is Fansidar?

Back 1145

combo drug of pyrimethamine and sulfadoxine
first line in developing world because cheap
2nd line in developed world because resistance exists

Front 1146

Pyrimethamine mech

Back 1146

inhibits parasitic dihydrofolate reductase, resulting in inhibition of tetrahydrofolic acid synthesis

Front 1147

Pyrimethamine resistance mech

Back 1147

point mutations in parasite dihydrofolate reductase-thymidylate synthase enzyme
(decreases drug binding at active site)

Front 1148

Where and for what is artemisin used?

Back 1148

Asia for quinine resistant P. falciparum
not licensed in US.

Front 1149

Mech of artemisin

Back 1149

bind iron in malarial pigment, produce free radicals that damage parasite proteins

Front 1150

What is Malarone?

Back 1150

atovaquone and proguanil hydrochloride (antimicrobial).
combo b/c atovaquone develops resistance when used alone

Front 1151

Malarone treats

Back 1151

acute, uncomplicated P. falciparum malaria
acute, mild-to-moderate Pneumocystis carinii pneumonia in Septra intolerance

Front 1152

Malarone admin

Back 1152

PO

Front 1153

Atovaquone mech

Back 1153

selective inhibitor of mitochondrial electron transport (cytochrome bc1 complex) of Plasmodium.

Front 1154

Proguanil hydrochloride mech

Back 1154

it's metabolite cytoguanil is a dihydrofolate reductase inhibitor (disrupts deoxythymidylate synthesis)

Front 1155

Atovaquone resistance mech

Back 1155

single point mutations in cytochrome-b gene

Front 1156

Ivermectin treats

Back 1156

intestinal Strongyloides stercoralis
larval Onchocerca volvulus

Front 1157

Ivermectin mech

Back 1157

potent agonist at GABA receptors, paralyzing parasites
(doesn't cross BBB, so not paralytic to humans)

Front 1158

How is ivermectin acquired?

Back 1158

produced by Streptomyces avermitilis
(a member of avermectins, macrocyclic lactones that are produced by this organism)