Microbiology Test 2 - Helminths And Other Bull

Front 1

Enterobius vermicularis
Common name
Disease
Distribution
Host?

Back 1

pinworm
enterobiasis (oxyuriasis)
Worldwide (most common helminth infection)
Humans only known host

Front 2

E. vermicularis
Morphology
How infected?

Back 2

0.5 - 1 cm long
Transmission by fomites
Ingestion of eggs
Eggs can be airborne

Front 3

E. vermicularis
Where are eggs laid?
What is the infective stage?
When are eggs infective?
How long can they survive indoors?

Back 3

perianal folds (transmitted by scratching)
Eggs are infective
Eggs develop en route to colon
infective in 4-6 hours, survive 2-3 weeks indoors

Front 4

E. vermicularis
How many infxs are symptomatic?
Symptoms of infection?

Back 4

2/3 symptomatic
Most common: anal itching
2y bacterial infection common from itching.
Ab pain, poor sleep, general irritability/anxiety
(can oviposit in the special lady parts)

Front 5

E. vermicularis
How confirmed for infection?

Back 5

Cellophane tape test around anus.

Typically few eggs or worms in feces

Front 6

E. vermicularis

DOC? What if pregnant?
Prevention?

Back 6

Albendazole
Mebendazole (outside of US)
pyrantel pamoate for preggos
(treat everyone, prevent through handwashing and washing bedding and clothes)

Front 7

Soil-transmitted Nematodes
What routes of transmission?
Give examples?

Back 7

1)egg ingestion - Ascaris lumbricoides
trichuris trichiura (whip worm)

2) Skin penetration - Hookworms( Ancylostoma duodenale
Necator americanus)

Strongyloides stercoralis (threadworm)

Front 8

A. lumbricoides--
Morphology?
Resistance of eggs?
Distribution?
Infection route?

Back 8

30 cm long (females lay 200,000 eggs/day)

Eggs are highly resistant (freezing) >10 yrs infective
Worldwide
Infection via ingestion

Front 9

A. lumbricoides -- life cycle

Back 9

Eggs ingested hatch in SI
Larvae migrate from SI to colonize lungs
Larvae crawl up to pharynx, are swallowed
Larvae grow up to worms in SI

Front 10

A. lumbricoides -- Clinical characterisitcs

Back 10

Asymptomatic often, children generally show symptoms

Pulmonary infection: cough, wheezing, respiratory signs symptoms
Loeflers pneumonia in heavy infection
Intestinal distress in intestinal infection

Front 11

A. lumbricoides - malabsorption?

Back 11

Lactose, protein, vit A &C
(can be fatal in small children)

Front 12

A. lumbricoides

Dx, treatment, prevention

Back 12

DOC: Albendazole, mebendazole PP for preggos

Prvnt - don't eat dirt, wash hands
Wash peel cook soil grown stuff
Manage feces

Front 13

Trichuris trichiura (Whipworm)
Morphology?
Host?
Distribution?
How spread?

Back 13

30-50mm
Humans only known host
Worldwide (common in SE US)
Co infection with A. Lumbricoides common

Front 14

Trich trich - Life Cycle

Back 14

Infective eggs hatch in SI
Over 2-3 mo inhabit caecum and ascending colon
Lifespan: 1-3 years
(these go south, versus Asacris, which burrows in lungs)

Eggs become infective in 15-30 days under optimal conditions

Front 15

Trich trich (whipworm) - Clinical signs and symptoms

Back 15

Light infections <100 worms = asymptomatic
100 - 1000s of worms
Lots of BMs with pain, mucus and blood
-colitis dysentery
-Rectal prolapse possible
-Children: stunt growth, retardation, impaired cognitive development

Front 16

Trich trich - Dx, trt, prvnt

Back 16

ID eggs in fecal sample
DOC: mebendazole, albendazole
Prevention - same as Ascaris (fecal management, wash hands, wash cook, peel the food grown in the dirt)

Front 17

Hookworms (Necator americanus and ancylostoma duodenale)
Morphology?
Distribution?

Back 17

10mm long
Worldwide distribution -- prevalent in tropical regions
Once very common in SE US
~65000 deaths per year out of 650 - 750 million infections

Front 18

Hookworm Lifecycle

Back 18

-eggs passed in stool, hatch in 1-2 days (optimal)
-Larvae develop to infective stage in ex. environment (infective stage)
-Extend themselves and enter host bloodstream
-Migrate to lungs
- 8 - 21 days larvae migrate through alveoli and ascend pharynx
-Swallowed (a. duodenale can be tx'd through muttersmiche)
-Attach to SI mucosa and mature

Front 19

Hookworm infections

Back 19

- Generally asymptomatic
-Ground itch (larval penetration of skin)
- Transpulmonary generally asymptomatic (respiratory symptoms can develop)

Front 20

Hookworm infx (intestinal phase)

Back 20

Signs/Sxs : nausea, epigastric pain, anorexia, geophagy

Hookworm disease caused by chronic infx

Front 21

Hookworm Disease

Back 21

Anemia, protein deficiency (poor skin/nails)
children: growth stunted, impaired cog development

Front 22

Hookworm Disease Dx

Back 22

ID eggs in stool
Treat with albendazole, mebendazole, PP if preg

Fe supp is anemic

(managed by human feces control and avoiding contact with known infxtious soil

Front 23

Threadworm

Back 23

Strongyloides stercoralis
Causes strongyloidiasis

Front 24

Threadworm Morphology
Definitive host
Distribution
Other forms?

Back 24

Small (~2mm)
Cosmopolitan, common in US
Parasitize dogs, cats, mammals, primates
Has free living form
Primarily SE if US

Front 25

S. stercoralis: Life cycle

Back 25

-Larvae attach to skin and swim through blood to lungs
-Ascend pharynx and are swallowed
-Develop in SI, larvae can autoinfect
-Immune system can limit and make it chronic infx
- Larvae are released in stool
- Can become free living or parasitic

Front 26

S. stercoralis: symptoms

Back 26

General pulomonary and abdominal symp
Chronic skin infection: urticaria and itchy
-Larva currens: autoinfx leads to red raised track on buttocks and thigh

Front 27

S. Stercoralis- rare complication

Back 27

Hyperinfection syndrome.
Bug is dissemminated, causes sepsis, and multiorgan failure (migration to CNS, liver, kidneys and lungs

Front 28

Threadworm diagnosis:

Back 28

Larvae in stool sample, duodenal aspirate
Hyperinfection: larvae in sputum
DOC: ivermectin
Prevent by avoiding infested soil and managing feces

Front 29

Tapeworms

Back 29

Cestodes
Segmented (Proglottids)
Hermaphrodites
Have no gut

Front 30

Tapeworm lifecycle

Back 30

Requires 2 hosts: intermediate host, definitive host
Intermediate host is eaten by definitive host and becomes infected

Front 31

Beef tapeworm

Back 31

T. saginata

Front 32

Pork tapeworm

Back 32

T. solium

Front 33

Tapeworm epidemiology + morphology

Back 33

More common where raw beef and pork are eaten
Can grow several meters long
Humans only known definitive host

Front 34

Tapeworm lifecycle

Back 34

Eggs ingested by livestock, eggs hatch into larvae in SI, tapeworm penetrate gut and migrate to striated muscle develop cysticerci

Front 35

cysticerci

Back 35

larval cysts

Front 36

T. saginata can infect?

Back 36

Cows and other bovids (antelope, deer for example)

Front 37

T. solium can infect?

Back 37

infect humans, some other mammals

Front 38

Where do ingested eggs develop?

Back 38

Ingested cysticerci develop in SI (takes 2 months)
Proglottids are passed in feces to spread infection

Front 39

Cysticercosis

Back 39

larval cysts in muscle, brain, other organs of humans. potentially fatal

Front 40

Taeniasis

Back 40

Most infections are asymptomatic
Abdominal symptoms, can notice proglottids in stool
T. saginata can crawl out on its own

Front 41

Cysticercosis symptoms

Back 41

No major signs unless in eyes or CNS
-visual disturbances/blindness
-neurocysticercosis symptoms are non specific

Front 42

T. sag and T. solium dx

Back 42

presence of proglottids in stool

Front 43

Dx of cysticercosis

Back 43

Imaging studies (MRI, CT)
Biopsy and ELISA type immunoblot assays

Front 44

Treatment of Tapeworm infection

Back 44

praziquantel (taeniasis)
albendazole (cysticercosis)
-cysticercosis may require surgery and other drugs to control symptoms

Front 45

Prevention:

Back 45

cook meats to safe temperature
handwashing
feces management

Front 46

Broad fish tapeworm

Back 46

diphyllobothriasis
Longest tapeworm up to 12 meters

Front 47

Diphyllobothrium latum definitive host

Back 47

bears, dogs, cats, humans

Front 48

Broad fish tapeworm infection

Back 48

mostly in Northern Hemisphere (Northern Europe and Japan)
-poorly cooked fish dangerous
-pickled salted and smoked can be dangerous too

Front 49

D. latum lifecycle

Back 49

larvae ingested in muscle of predatory fish
-worms mature in SI, eggs appear in feces 5-6 weeks later and hatch in water
-multiple larval stages (works its way up foodchain)

Front 50

D. latum clinical presentation

Back 50

Mostly asymptomatic (worms can live for 10 years)
S/Sx: abdominal discomfort, nausea diarrhea, vomiting
Prolonged infection: megaloblatisc anemia due to B12 deficiency
-Rare: found in people with predisposition to b12 deficiency

Front 51

D. latum - confirmation and treatment

Back 51

Eggs in stool
DOC: praziquantel
Prevention: avoid raw fish
Prevent human feces from entering fresh water

Front 52

Common name of intestinal and liver trematode

Back 52

Flukes

Front 53

Fluke morphology

Back 53

flat worm ( full gi and oral and ventral suckers)

Front 54

Fasciolopsis buski

Back 54

Giant intestinal fluke
20-75mm
encysted water plants cause infection
Humans & pigs = reservoir and definitive host
Occurs in S and SE Asia

Front 55

F. buski S/Sx, Dx, Tx

Back 55

Infx mostly asymptomatic, heavy infections cause abdominal symptoms

Dx with eggs or worms in stool

DOC: praziquantel

Cook all quatic plants, manage human and pig feces

Front 56

Clonorchis sinensis

Back 56

Chinese oriental liver fluke

Front 57

Clonorchis sinensis can infect?

Back 57

Biliary ducts and release eggs in feces

Front 58

C. sinensis important reservoirs?

Back 58

Dogs and cats

Front 59

C. sinensis definitive host?

Back 59

Humans; carnivores

Front 60

C. sinensis encysts in snails and...

Back 60

can hatch and free swimming larvae looks for fish to infect

Front 61

C. sinensis DOC

Back 61

praziquantel