Viral Infection Chicken Pox

Question 1

How specific are herpes virus

Answer 1

Species specific can’t transfer between humans and animals

Question 2

How many herpes viruses

Answer 2

100 c

Question 3

During lyric infection

Answer 3

Host cells productively infected- new Virions made

Question 4

Latent infection

Answer 4

After primary infection virus isn’t eradicated.

Latent infection no new virions made

Reactivation may occur from latent state

Question 5

Zero positive status means?

Answer 5

Infection and not immunity

Question 6

Antiviral agents fa do what to herpes

Answer 6

Can control productive herpes but not eradicate latent infection

Question 7

Vricallea zoster virus classification

Nucleic acid
Capsid symmetry 
Envelope ?
Genome architecture
Genome size

Answer 7

Nucleic acid DNA
capsid symmetry Icosahedral
Envelope
Ds
125 kbp 70 genes

Question 8

VZV infectious n who

Answer 8

Only humans

Question 9

VZV primary and secondary infection outcome

Answer 9

Primary chicken pox

Secondary shingles

Question 10

Varicella clinical features

Incubation?
Prodrome
Macule….
More severe in?

Answer 10

10-21 days

Asymptomatic uncommon

Prodrome: fever pharyngitis, malaise itchy painful lesions appear in crops

Macule-papule-vesicles-pustule- crusts

More severe in adults/ immune compromised

Question 11

Varicella complications

Answer 11

Severe/haemorrhaging varicella
Pneumonia in adults
Acute cerebellum ataxia 
Encephalitis 
Secondary bacterial infection

Question 12

When is chicken pox infectious from

Answer 12

48 hours before rash appears (prodrome)

Question 13

After naturally acquired primary VZV infection what occurs

Answer 13

VZV specific igG and VZV igA antibodies

VZV specific CD8 and CD4 T cells

Question 14

Zoster (shingled) clinical features

Answer 14

Common
Reactivation of VZV
Pain at site may precede eruption of painful vesicles

Unilateral 1-2 dermatomes involved
Incidence increase with age

Ophthalmic division of trigeminal nerve—>involvement of eye in 50%

Question 15

What % of shingles are where

Answer 15

50 thoracic
20 cranial
14 trigeminal
16 lumbosacral

Question 16

VZV mode of transmission

Answer 16

Horizontal : spread by respiratory route! Commencing 48 hours before onset of rash

Skin lesions of varicella and zoster are infectious till crusted over

Vertical- only to fetus

Question 17

Determine VZV susceptibility

Answer 17

History of chicken pox or shingles

Varicella-zoster specific igG status

Question 18

Post exposure prophylaxis

Answer 18

Aciclobir- some evidence of protection of normal household contacts

Varivax vaccine- may be contraindicated
Administer within 72 hours of exposure

VZIG

Prevents or ameliorates chicken pox
Administer within 7 days of significant contact

Question 19

VZV anti viral therapy is recommended for

Answer 19

Varicella I. Adults or immunocompromised individuals

Treatment of zoster

Question 20

First line antiviral agents fir VZV

Answer 20

Aciclovir (ponor iv)
Valaciclovir po
Famiciclocvir (po)

Question 21

Oka varicella vaccine

Answer 21

Live attenuated vaccine

Part of routine childhood vaccination schedule of USA
2 dose schedule
Recommended in UK for
- susceptible healthcare workers
-susceptible household contacts of immunocompromised patients

Question 22

Zoster vaccine

Answer 22

Zostavax
No major safety concerns but contraindicated in significant immune deficiency

Recommended for 70 year olds