(32) Viruses Affecting the CNS Flashcards Preview

Neuro Block 2 > (32) Viruses Affecting the CNS > Flashcards

Flashcards in (32) Viruses Affecting the CNS Deck (42):
1

What levels for the following labs suggest bacterial etiology of meningitis?
CSF glc
CSF protein
CSF WBC
CSF neutrophil

CSF glc < 34
CSF protein > 220
CSF WBC > 2000
CSF neutrophil > 1180

**only need 1 of the above to make Dx**

2

presentation of viral meningitis

fever, malaise, neck stiffness, low back pain

3

etiologies of viral meningitis

80% from enterovirus (Echo, Coxsackie, enterovirus 71)

10% from Mumps (prior to MMR vaccine)

4

recurrent aseptic meningitis is due to

HSV-2 (genital herpes)

5

HIV and VZV cause ______ meningitis

recurrent

6

What are the 3 etiologies of viral encephalitis

arbovirus (West Nile, St louis, La Crosse)
enterovirus
HSV-1

7

clinical course of viral enchephalitis

preodromal URT infection
fever
headache
letharghy
parenchymal involvement = seizures, coma, death

8

what is the treatment for HSV-1 encephalitis

acyclovir

9

what is the treatment for CMV encephalitis

gancyclovir

10

HSV encephalitis is more common in (acute, reactivation, or latent) infection

reactivation of latent

11

Where in the brain does HSV encephalitis characteristically cause damage

temporal lobe (due to necrosis)

12

What are the mosquito borne encephalitis viruses?

Flaviviruses = west nile and st. louis

alphaviruses = eastern, western, and venezuelean equine

bunyavirus = California encephalitis, la crosse virus

13

What are the animal transmitted encephalitis viruses?

rhabdovirus (rabies) and arenavirus (LCMV = lymphocytic choriomengingitis virus)

14

structures of flavivirus (West nile and St. louis)

enveloped + RNA

15

describe the replication cycle of the flavivirus

enter via receptor mediated endocytosis. low pH allows membrane fusion and then uncoating. + strand translated into Rdrp. + strand is used to make - strand which is then used to make progeny. virion assembly and budding

16

all flaviviruses are transmitted by ____

insect vectors

17

what are flaviviruses that cause dz in US

west nile, st louis, yellow fever, dengue (usually traveled abroad)

18

length of incubation prd for SLE

4 - 21 days

19

how long after URT/primary viremia will neurological symptoms of SLE present

1-4 days

20

describe the transmission cycle of the west nile virus

bird reservoir and mosquito vector to infect humans

21

distinguishing characteristic/presenting signs and symptoms of west nile infection

rash and lymphadenopathy

22

most significant etiology of arboviral encephalitis

Japanese encephalitis virus

23

structure of togavirus (alphavirus)

enveloped, non-segmented + RNA

24

vector for alphaviruses

mosquito

25

what determines the severity of the dz in alphavirus infections?

dept on dose and age of pt

26

describe the typical dz progression of an alphavirus infection

fever for 7 to 11 days then resolution of abrupt onset of encephalitis with vomitting, dizzynes, confusion. 2-3 days and person becomes comatose and dies

27

describe the structure of the bunyaviruses

enveloped, ss - RNA

28

what is the most common cause of arboviral induced pediatric encephalitis in US

La crosse virus

29

structure of rabies virus

enveloped, nonsegmented - RNA
**bullet shaped morphology**

30

describe the replication cycle of rhabdoviridae

endocytosed and used glycoprotein to attach at fuse (pH dept process) Rdrp is packaged in virion with - RNA so when uncoated a + RNA is made. This RNA serves as the template for the progeny -RNA and the code for the RDRP to be made to be packaged with the - RNA

31

Why does rabies virus characteristically involve the CNS

the attatchement glycoprotein shows neurotrophism

32

during the final stages of rabies, high conc of virus can be found in what organ

salivary glands

33

how is rabies transmitted

animal bite, sratch, lick

34

what is the incubation period for rabies

usually 2-3 mos (BUT can be as short as 1 week)

35

what determines the incubation period for rabies

proximity of bite to CNS

36

Describe the progression of the dz caused by rabies

1. prodromal = 2-10 days after exposure in which pts has fever, malase, and headache

2. neurologic phase = mos to years after exposure in which the pt gets anxiety, agitation (when enchephalitis develops), paralysis

3. coma and death 2-7 days after acute neuro phase and can last 3 days to ~ 1 month

37

treatment after bite from rabies infected animal

2qw wound and admin human anti-rabies Ig to wound and admin rabies vacine IM on days 0, 3, 7, 14, 28

38

what type of vaccine is rabies virus

inactivated

39

describe the structure of LCMV

enveloped, segmented, ambisense RNA (2 segements)

40

describe the replication scheme of LCMV

endocytosed

NP portion of S strand is replicated first then GP then L portion of L strand

?????

41

how is arena virus transmitted`

inhalation of aerosolized rodent excreta and saliva

42

describe the phases of LCMV/arenavirus dz progression

prodrome of fever headache, N/V. 10 days later get aseptic meningitis (rarely fatal)