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Flashcards in VZ + HHV 6/7 Deck (27)
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1

Describe HHV 6/7 and VZV

They are all linear, enveloped, dsDNA large genome (150-250 kbp) with an icosahedral capsid and about dozen of glycoproteins inside; they are all herpesviruses

2

What do the glycoproteins of HHV6/7 and VZV do?

They are for attachment, penetration, and release

3

Where are the HHV6/7 and VZV viruses assembled inside the cell?

In the nucleus

4

What kind of infections to the herpesviruses produce?

Generally self limiting, but life threatening infections can occur in ICP's

5

Describe the life cycle of a Herpesvirus? (3 phases)

Establishment, Maintenance, and Reactivation; First the initial infection, then goes into latent period in which no virus is produced and the genome is maintained extrachromasomally (undetectable), then it is reactivted usually due to a lapse in host immune status

6

Where does VZV go latent?

Neural cells (it is a alphaherpesvirus)

7

Where do HHV 6/7 go latent?

Lymphocytes (it is a betaherpesvirus)

8

What is the primary infection of VZV? secondary?

Chickenpox; shingles

9

How is VZV spread?

It is highly communicable and by aerosol, late winter and early spring

10

What are the symptoms of chickenpox?

Fever and then itchy rash starting on scalp and trunk, can radiate from there

11

Describe adult chickenpox

Usually more severe, less rash, chance of pneumonia

12

Describe the infection of chickenpox in a child

Initial respiratory infection leads to replication in mucosa of URT, virus then spreads and replicated in regional lymph nodes which results in primary viremia around day 4-6. Virus progresses to liver and spleen and leads to secondary viremia around day 12-14

13

When does the rash appear in chickenpox for a child?

Only after the secondary viremia (around 12-14 day post exposure)

14

When is a child good to go back to school after a bout of chickenpox?

Only after the rash has scabbed over, before they are still contagious

15

What is the reactivated form of chickenpox (Varicella) called?

Shingles (Zoster)

16

What is shingles characterized by?

Sudden onset of pain and rash along a single dermatome (unilateral) or forehead; rash can last 2-4 weeks with pain lasting longer (postherpetic neuralgia) and most people only have it ONCE

17

How is VZV diagnosed?

Clinically

18

Describe the VZV vaccine

Approved live attenuated vaccine recommended as part of MMR regimen, there is no evidence of reactivation to shingles

19

What other drugs can treat chickenpox?

In immunocompromised kids use Acyclovir

20

What may adult pneumonia require?

VZV Ig

21

What do you exactly "treat" for chickenpox?

Symptoms

22

How is Zoster treated?

Oral ACV and steroids (faster the better)

23

What is the Zoster vaccine?

Booster to prevent or lessen zoster for patients 50 years or older

24

What do HHV 6/7 cause?

Roseola (exanthem subitum)

25

What is Roseola?

Mild respiratory illness followed by high fever

26

How many kids will get the body rash associated with Roseola?

As few as 25% on face and body

27

What group of people does HHV 6/7 infect?

3 months to 6 years old; 90% of US is seropositive