varicella-zoster virus and HHV 6 and 7 Flashcards Preview

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Flashcards in varicella-zoster virus and HHV 6 and 7 Deck (33)
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1

varicella zoster, HHV-6, and HHV-7 are all ______ viruses.

herpes viruses

2

describe genome of herpes viruses

linear, ds DNA genome of 150-250kbp

3

what type of capsid do herpes viruses have?are they enveloped? what is contained in the capsid?

icosahedral capsid, enveloped, dozen glycoproteins(involved in attachment, penetration, and release of virus from cells)

4

where is viral DNA replicated in the cell? how about viral assembly?

nucleus of host cell

5

in general, what type of infection do herpes viruses produce?

self-limiting infections, but life-threatening infections can occur especially in immunocompromised hosts

6

what are the three classifications of herpesviruses?

alpha(HSV-1, HSV-2, VZV) , beta(CMV, HHV-6, HHV-7), gamma(EBV, HHV8)

7

which class of herpes virus does varicella belong to? what is its tropism?

alphaherpesvirus and it is neurotropic (stays latent in neurons)

8

which class do HHV-6 and HHV-7 belong to? In which cells do they become latent?

betaherpesviruses
lymphocytes

9

what is the hallmark of herpes infections?

latency

10

when does latency occur?

soon after initial infection

11

during latency are virus particles produced? what is the location of the genome? are viral genes expressed

no virus particles produced
ENTIRE genome maintained extrachromosomally
few viral genes are expressed

12

what are the three stages of latency? think: EMR

establishment, maintenance, reactivation

13

the primary infection of varicella results in ______?

chicken pox

14

varicella mode of tranmission?

highly communicable, spread by aerosol

15

during which time of year is varicella most common?

late winter/early spring

16

presentation of varicella zoster?

fever followed by itchy rash starting on scalp and trunk

17

what do adult cases of varicella result in?

adult cases can be more severe, resulting in pneumonia

18

describe timecourse of varicella infection

Day 0 = infection of conjuctivae and/or mucosa of URT -->viral replication of regional lymph nodes

Day 4-6=primary viremia --> viral replication in liver, spleen, and other organs --> secondary viremia

Day 14 = infectio nand appearance of vesicular rash

19

what does the reactivation of VZV cause?

shingles = zoster

20

presentation of shingles

sudden onset of pain and rash along thoracic dermatome or forehead

21

what is peculiar about the pain in shingles?

rash in shingles may last 2-4 weeks, but pain can last much longer: postherpetic neuralgia

22

how is VSV diagnosed?

clincially

23

is there a vaccine for VSV?

yes, FDA approved live attenuated vaccine (recommended as part of MMR regimen)

24

how is chickenpox treated?

treat symptoms: aches and pains

25

what may the tx of adult pneumonia require?

VZV Ig

26

how is zoster treated?

with oral acyclovir and steroids

27

what is the VSV vaccine designed for?

designed to boost immunity to prevent or lessen zoster

28

HHV-6 and HHV-7 cause ____

roseola (exanthem subitum)

29

symptoms of roseola

mild respiratory illness followed by high fever

30

t/f. after roseola fever, as few as 25% of kids will exhibit rash on face and body that will last 2-3 days

true