Encephalitis Virus

Front 1

What is aseptic meningitis caused by?

Back 1

Echoviruses, Coxsackie A&B, HSV-1 and 2, VZV, EBV, CMV, HIV, Adeno, Influenza, and Mumps

Front 2

Clinical symptoms of aseptic meningitis?

Back 2

Infection of meninges
Fever, headache, and nuchal rigidity, +/- maculopapular rash and conjunctivitis
Clear mentation and no focal neurologic findings

Front 3

What is the most common cause of encephalitis?

Back 3

virus

Front 4

Encephalitis clinical symptoms

Back 4

Infection of cerebral cortex +/- meninges
Severe headache, nuchal rigidity, sensory or motor deficits, seizures, hallucinations, mental changes
Difficult to determine etiology

Front 5

What does ARBO in arboviruses stand for?

Back 5

arthropod-borne virus

Front 6

How are arboviruses transmitted?

Back 6

mosquitos and ticks
-Acquired by arthropods via blood meal.
-Transmitted via saliva during biting
only female mosquitoes bite
Zoonoses

Front 7

extrinsic incubation period definition?

Back 7

the time before the virus has replicated enough to provide an infectious dose through the saliva.

Front 8

For arboviruses humans are?

Back 8

dead end hosts, because the level or duration of viremia is too small for effective viremia.

Front 9

What two arbovirus diseases are humans significant resiviors?

Back 9

yellow fever and dengue. non-encephalitis viruses.

Front 10

how do you diagnose arboviruses?

Back 10

Patient’s history, serology and PCR
Difficult to isolate virus from CSF or blood

Front 11

Where do arboviruses replicate?

Back 11

Replicates in vascular endothelium/lymphatic tissue

Front 12

what do arboviruses do to damage cells?

Back 12

Induces cell necrosis/inflammation

Front 13

common clinical symptoms of arboviruses are?

Back 13

Flu-like symptoms with fever or asymptomatic

Front 14

Arbovirus infection steps?

Back 14

After local replication, low level viremia followed by secondary viremia to various tissues
Enter CNS via cerebral microvasculature, diapedesis of infected leuckocytes, penetraton of choroid plexus or axonal transport

Front 15

How do you help prevent arbovirus diseases?

Back 15

Insect control to prevent disease
Protective clothing and insect repellent

Front 16

What are treatments? Herpes? HIS?Enteroviruses?

Back 16

Treatment is normally supportive.
Acyclovir if suspect members of Herpesvirus family
Antiretrovirals for HIV
Immune globulin for Enteroviruses

Front 17

Togavirdae genes?

Back 17

Togaviridae (Genus alphavirus)(+ssRNA, enveloped, icosahedral)

Front 18

Name two togavirae viruses that cause encephalitis?

Back 18

Eastern Equine Encephalitis virus and Western equine encephalitus virus.

Front 19

Describe EEE

Back 19

Swamp mosquitos
Culiseta/Aedes
Reservoir is wild birds
Humans/horses incidental hosts/dead end hosts
Incidence highest in infants/children
Rare but severe disease
Sudden onset
Confusion and stupor
Progresses to coma,nuchal rigidty and seizures
33% mortality
Diagnosis by IgM in CSF
Equine vaccine and lab workers (for horses not humans)
Atlantic and gulf states.
Most severe disease with 50% mortality

Front 20

Describe WEE

Back 20

WEE
Western states-Irrigated farmland
Culex
Reservoir is wild birds
Humans/horses incidental hosts
No cases in US since 1994
Symptoms similar to EEE but less severe
5% mortality but 60% residual neurological damage
Equine vaccine and lab workers (horse only)
Less severe than EEE

Front 21

Describe the Flaviruses' genome:

Back 21

+ssRNA, enveloped, icosahedral, mosquito vector

Front 22

Name two important encephalitis flaviviruses:

Back 22

St. Louis Encephalitis virus
WNV

Front 23

Name two important Hemorrhagic fevers flaviviruses:

Back 23

Dengue
Yellow fever

Front 24

St. Louis Encephalitis Virus is tranmitted by X in what areas?

Back 24

Transmitted by Culex mosquito in urban areas

Front 25

St. Louis Encephalitis Virus is a major cause of?

Back 25

A major cause of arbovirus encephalitis in US
35 cases/year

Front 26

St. Louis Encephalitis Virus has its highest incdence in what age group?

Back 26

Incidence highest in adults > 40 years of age

Front 27

St. Louis Encephalitis Virus resiervoir is?

Back 27

Reservoir is wild birds

Front 28

St. Louis Encephalitis Virus severity level is?

Back 28

Moderate severity (4-27%)

Front 29

St. Louis Encephalitis Virus is diagnosed by?

Back 29

Diagnose by IgM in CSF

Front 30

West Nile Virus (WNV) is the most coomon cause of?

Back 30

Most common cause of viral epidemic encephalitis

Front 31

West Nile Virus (WNV) is transmitted by?

Back 31

Transmitted by Culex mosquito

Front 32

West Nile Virus (WNV) reservior is?

Back 32

Reservoir is birds (bluejays/crows in US)

Front 33

West Nile Virus (WNV) waht is the incubation period? how many get symptoms? how many get meningoencephlaitis? and who gets it?

Back 33

Incubation period of 3-14 days
Only 20% develop symptoms of West Nile Fever
1 in 150 develop meningoencephalitis; primarily elderly
12% mortality

Front 34

West Nile Virus (WNV) was first seen where? Over time the freq and severity of cases have?

Back 34

First identified in Uganda in 1937
First case in US in 1999; now >28,000 cases
Frequency and severity of cases have increased

Front 35

West Nile Virus (WNV) diagnosed by?

Back 35

Diagnose by IgM in CSF

Front 36

Yellow Fever vector is?

Back 36

Vector = Aedes
Urban/jungle

Front 37

Yellow Fever reservoir is?

Back 37

Reservoir is monkeys

Front 38

Yellow Fever replicate in which cells?

Back 38

Replicate in monocytes and fixed macrophages

Front 39

Yellow Fever disrupt what?

Back 39

Disruption of clotting factors

Front 40

Yellow Fever incidence is high and low geographically where?

Back 40

Incidence low in SA but higher in west Africa

Front 41

Yellow Fever vaccine?

Back 41

Live, attenuated vaccine

Front 42

Yellow Fever differnitial is?

Back 42

Differential includes HAV, HBV, HCV, HEV, EBV

Front 43

Yellow fever sign and symptoms are?

Back 43

Acute onset of fever, chills, myalgia, nausea, vomiting, and jaundice
Brief remission followed by renal and liver failure
Widespread hemorrhages in liver, kidney (hemorrhagic hepatonephritis), skin and other organs; erosion of gastric mucosa
May be accompanied by SIRS
20% mortality

Front 44

How do you diagnose yellow fever?

Back 44

ELISA or PCR; elevated AST

Front 45

Another name for Dengue Fever and DHF?

Back 45

“Breakbone fever”

Front 46

What is DHF's vectos? where?

Back 46

Vector = Aedes
Urban/jungle

Front 47

Dengue Fever reservoir is?

Back 47

Reservoir is monkeys to humans via mosquito

Front 48

Dengue Fever has how many serotypes?

Back 48

4 serotypes of virus
Cross-reacting antibodies

Front 49

Dengue Fever replicates in what cells?

Back 49

Replicate in monocytes

Front 50

Dengue Fever disrupts?

Back 50

Disruption of clotting factors

Front 51

Dengue Fever cases per year is?

Back 51

50 to 100 million cases/yr

Front 52

Dengue Fever differential is?

Back 52

Differential includes Coxsackie B, R. rickettsii, Ebola, YFV

Front 53

In DHF what do the cross reacting antibodies do?

Back 53

Develop cross-reacting antibodies after first infection that may enhance subsequent infections

Front 54

DHF symptoms are?

Back 54

Signs/symptoms
High fever +/- rash
Myalgias and/or bone or joint pain (joint and bone pain=breakbone fever)
Thrombocytopenia
Elevated hematocrit
Hypotension
Hemorrhagic shock may occur in subsequent infections; mediated by antibody
Enlarged lymphnodes
Leukopenia

Front 55

DHF treatment is?

Back 55

Treatment
Maintain circulating fluid volume

Front 56

DHF diagnosis is?

Back 56

Diagnosis
ELISA

Front 57

What happens when infected with one DHF type? A second differnt DHF?

Back 57

If a person is infected with one serotype of dengue, they will develop antibodies that are not necessarily neutralizing.
When infected with a second serotype, the antibody forms a complex with the virus that is bound by monocyte Fc receptors thus enhancing the infection and increasing the release of cytokines
and inducing shock

Front 58

Where did DHF epedemics take place?

Back 58

US port cities that traded with the west indies

Front 59

Any DHF vaccine has to be?

Back 59

Any vaccine has to be tetravalent to induce protective antibodies against all 4 serotypes

There is no vaccine

Front 60

DHF can be used as a potential?

Back 60

bioterrorism weapon!

Front 61

DHF is currently a big problem where?

Back 61

Africa and south america

Front 62

ST Loius virus geography?

Back 62

southern,central,and western states, urban areas.

Front 63

St. Loius virus vaccine?

Back 63

there is none

Front 64

st louis virus vaccine?

Back 64

none.

Front 65

Dengue breakbone Fever symptoms

Back 65

flu,fever,pain in joints and bones, leukopenia, and enlarged lymph nodes

Front 66

Dengue Hemorrhagic fever

Back 66

By subsequent infection, 10% mortality. Shock, hemorrhage into Gi and skin, production of cross reacting antibody from first infection

Front 67

DHF chances are increased by?

Back 67

traveling to foreign coutnries

Front 68

DHF vaccine?

Back 68

none

Front 69

Bunyaviridae genome is?

Back 69

(-)ssRna, enveloped, with helical nucleocapsids.

Front 70

Name two arboviruses from Bunyaviridae?

Back 70

California encephalitis virus and Reovirdae

Front 71

California encephalitis geography? seasons

Back 71

northcentral states: summer and fall in forest areas.

Front 72

California encephalitis is tranmitted by what?

Back 72

transmitted by mosquito Aedes triseriatus

Front 73

California encephalitis has the highest incidence in what age group?

Back 73

Highest incidence in age group of 5-18 years old

Front 74

What is the most prominent strain in California encephalitis?

Back 74

LaCrosse strain most prominent

Front 75

California encephalitis severity?

Back 75

mild to severe; mortality rare

Front 76

California encephalitis vaccine?

Back 76

none

Front 77

California encephalitis reservoir?

Back 77

rodent

Front 78

California encephalitis diagnosis?

Back 78

diagnose by IgM in CSF or blood

Front 79

California encephalitis differntial?

Back 79

Differential includes WNV, SLE, EEE, WEE, HSV

Front 80

Give clinical symptoms of Hantavirus (sin nombre)-pulmonary syndrome

Back 80

-Cough, myalgia, tachycardia, pulmonary edema, and hypotension (50% mortality)
-Exposure to rodent excrement in the four-corners region of US
-Differential includes L. interrogans, S. pneumonia, K. pneumoniae, M. pneumoniae, influenza

Front 81

Reovirdidae genes?

Back 81

75 nm dsRNA, naked, icosahedral, double-shelled capsid

Front 82

Colorado Tick Fever Virus (CTF) is ?

Back 82

Transmitted by wood tick Dermacentor andersoni

Front 83

Colorado Tick Fever Virus reservoir is?

Back 83

rodent reservoir

Front 84

Colorado Tick Fever Virus infects what cells?

Back 84

Infects erthyroid precursors and remains in mature erythrocytes

Front 85

Colorado Tick Fever Virus how many cases per year?

Back 85

100-300 cases per year in Rocky Mountain states

Front 86

Colorado Tick Fever Virus clinical symptoms?

Back 86

Fever, headache, retro-orbital pain,
severe myalgia (muscle pain),
hemorrhage, meningitis, or encephalitis

Front 87

Colorado Tick Fever Virus differntial?

Back 87

Differential includes R. rickettsii, EBV, influenza

Front 88

Colorado Tick Fever Virus vaccine?

Back 88

no vaccine!

Front 89

Rabies is from the family of?

Back 89

Rhabdovirus

Front 90

Rabies genes?

Back 90

negative ssRNA, enveloped
-Bullet-shaped particle w/ helical nucleocapsid

Front 91

Rabies host range is?

Back 91

Extremely broad host range: can infect all

Front 92

Rabies is primarily transmitted by?

Back 92

Primarily by the bite of an infected animal

Front 93

Rabies in the USA is transmitted by? Give five examples of animals with thiere states.

Back 93

by wild animal in United States
Raccoon (eastern US)
Skunk (north and south central US/California)
Bat (all US, except Hawaii)
Fox & coyote (Alaska, Arizona and Texas)
Mongoose (Puerto Rico)

Front 94

Rabies is transmitted how in developing countries?

Back 94

by dogs in developing countries (most US dogs and cats are vaccinated

Front 95

How do you get rabies without being bitten?

Back 95

non-bite exposure; inhalation of contaminated bat excretions/secretions. (Handle all bats as potentially infected!)

Front 96

Rabies symptoms 6x?

Back 96

Hallucinations
Bizarre behavior
Anxiety and agitation
Hydrophobia
Autonomic dysfunction
Ascending flaccid paralysis in some cases

Front 97

what kind of axon transport does rabies use?

Back 97

Retrograde axon transport

Front 98

How do you diagnose rabies in animals?

Back 98

Examination of brain tissue by fluorescent antibody test or histologic staining of Negri bodies (subcellular “virus factories”)
-Observation of animal (example: after dog bite)

Front 99

What are the four ways that you diagnose rabies in humans?

Back 99

Fluorescent-antibody staining of biopsy specimen
-RT-PCR
-Antibody titer
-Detection of Negri bodies in autopsy specimens of brain

Front 100

What are pre-exposure prevention methods? Who should do this?

Back 100

Vaccination of high risk persons
veterinarians, animal control and wild-life workers, researchers, travelers to endemic areas

Front 101

What are post-exposure rabies prevention methods?

Back 101

Wound should be cleaned by allowing it to bleed and then washed with soap and water
-Rabies vaccine: HDCV, human diploid cell vaccine; inactivated virus produced from cultured human cells; five doses given
-Human rabies immunoglobulin: RIG; single dose administered to bite area

Front 102

In order to help orevent rabies what is done to pets?

Back 102

Oklahoma state law requires that all dogs, cats and ferrets be immunized against rabies by or under the supervision of a veterinarian by the age of 4 months

Front 103

Rabies treatment?

Back 103

drug-induced coma and supportive care and iv ribavirin

Front 104

Prions characteristcs?

Back 104

are not viruses
protein-containing particles with no detectable nucleic acid
a normal cellular protein induced into an alternate conformation
resistant to heat (even cooking)
inactivated by protein-disrupting agents like phenol & bleach

Front 105

What do prions cause?

Back 105

Transmissible spongiform encephalopathies

Front 106

Transmissible spongiform encephalopathies give histopathology and morphology:

Back 106

cause spongy, “swiss-cheese” morphology in brain tissue
dementia, myoclonic jerking, ataxia, aphasia, visual loss, hemiparesis

Front 107

How are prions proliferated?

Back 107

Normal protein is expressed on the surface of nerve cells
The association of the normal protein with the abnormal protein somehow induces a conformational change in the normal protein and makes it pathogenic
Results in accumulation of amyloid fibrils and plaques

Front 108

Kuru is?

Back 108

spread by ritual cannibalism of Fore tribes in New Guinea (prion)

Front 109

Creutzfeldt-Jacob disease (CJD) found where, and in who?

Back 109

found sporadically worldwide (incidence of 1 per million)
generally found in older persons 50-70 yrs. of age

Front 110

Creutzfeldt-Jacob disease (CJD)

Back 110

iatrogenic transmission via corneal transplant, contaminated surgical instruments, ingestion of contaminated food or contact

Front 111

Creutzfeldt-Jacob disease (CJD) diagnosis by?

Back 111

definitive diagnosis by morphology of brain tissue at autopsy

Front 112

Creutzfeldt-Jacob disease (CJD) trtment? vaccine?

Back 112

no treatment, no vaccine

Front 113

Creutzfeldt-Jacob disease (CJD) family genetic?

Back 113

10% of cases are hereditary through the inheritance of a mutated form of PrP (prion protein)

Front 114

Creutzfeldt-Jacob disease (CJD) most cases are?

Back 114

sporadic.

Front 115

Variant Creutzfeldt-Jacob disease (vCJD) occurs in what age?

Back 115

younger people

Front 116

Variant Creutzfeldt-Jacob disease (vCJD) transmitted from?

Back 116

transmitted from BSE-contaminated beef

Front 117

Variant Creutzfeldt-Jacob disease (vCJD) prions?

Back 117

Isolated prions are chemically similar to those from BSE

Front 118

Variant Creutzfeldt-Jacob disease (vCJD) beef?

Back 118

No BSE in US; all beef and livestock importation from Britain banned (mad cow dz)

Front 119

Variant Creutzfeldt-Jacob disease (vCJD) has resulted in how many deaths?

Back 119

115 probable deaths from vCJD in Britain as of July 2002

Front 120

Two other prion dzs?

Back 120

Gerstmann-Staussler-Scheinker and Fatal familial insomnia

Front 121

Gerstmann-Staussler-Scheinker def?

Back 121

similar to CJD but has a differnt mutation than CJD in hereditary form. (prion)

Front 122

Fatal familial insomnia genes? symptoms?

Back 122

Is hereditary and characterised by progressive insomnia,dementia and death.

Front 123

Name three prion diseases of animals?

Back 123

Scrapie of sheep and goats
Bovine spongiform encephalopathy (BSE or “mad cow disease”)
feeding of improperly processed, scrapie-contaminated, sheep “protein” to cattle
Subsequently passes on to humans as vCJD
Chronic wasting disease of deer and elk

Front 124

Filoviridae genes?

Back 124

-ssRNA, enveloped, helical, filamentous

Front 125

Filoviridae causes has what two viruses?

Back 125

Ebola and Marburg viruses in Africa

Front 126

Filoviridae transmitted?

Back 126

Transmission via direct contact (blood, secretions)

Front 127

Filoviridae symptom?

Back 127

fatal hemorrhagic fevers

Front 128

Filoviridae reservoir?

Back 128

unknown reservoir

Front 129

Filoviridae potential to be?

Back 129

potential bioterrorism agents

Front 130

Rabies incubation period?

Back 130

2-16 weeks or more

Front 131

In the incubation period what happens to rabies virus?

Back 131

Rabies virus first multiply locally at the bite, and then spread to the CNS by retrograde axonal transport, and this leads to encephalitis.

Front 132

Rabies trtmnt?

Back 132

supportive only, no antivirals.

Front 133

Once rabies symptoms occur?

Back 133

Dz is almost 100% fatal.

Front 134

What are the three clinical phases of the rapies virus?

Back 134

Prodrome, Acute neurologic phase, and hydrophobia.

Front 135

Rabies prodromal smptoms?

Back 135

fever,malaise, anorexia, headache, photophobia, nausea, vomiting and sore throat

Front 136

Rabies acute neurologic phase symptoms?

Back 136

nervousness, apprhenision, hallucinations and hydrophobia! (from painful throat spasms and thus aversion to swallowing)

Front 137

Rabies final stage symptoms?

Back 137

within a few days progresses to seizures, paralysis, coma and death.