CSIM 1.20 - Herpes Virus 1

Question 1

In basic terms describe the life cycle of herpesviridae virus family?

Answer 1

Primary infection
Latency (lifelong)
Re-activation

Question 2

Name the 8 viruses within the herpesviridae family?

Answer 2

Herpes simplex virus (HSV) 1 + 2
Varicella-zoster virus (VZV) 
Cytomegalovirus (CMV) 
Epstein-Barr virus (EBV)
Human herpes virus 6
Human herpes virus 7
Human herpes virus 8 (Kaposi's sarcoma)

Question 3

Describe the life-course of herpes simplex virus infections?

Answer 3

Primary infection = lytic replication within epithelial cells
Latency = some of the virus may enter the sensory neuronal nerve ends and travel up to the cranial nerve ganglia
Re-activation = trigger causes the virus to travel down the same sensory nerve and re-affect the area

Question 4

Describe the epidemiology and transmission of herpes simplex viruses?

Answer 4

Most primary infections occur

Question 5

Name the two types of disease caused by herpes simplex virus infections?

Answer 5

Primary oral herpes

Genital herpes

Question 6

Describe HSV primary oral herpes infections?

Answer 6

Primary infection - HSV-1 and HSV-2 = usually asymptomatic however gingivostomatitis may present
Oral Re-activation usually HSV-1 = cold sores

Question 7

Describe HSV genital herpes infections?

Answer 7

Primary infection - HSV-1 and HSV-2

Re-activation mainly HSV-2 = infection more severe

Question 8

Name four complications associated with HSV infections?

Answer 8

Secondary bacterial infections
Corneal scarring
Reoccurring meningitis (mollerat’s)
HSV encephalitis (70% mortality)

Question 9

Name and describe the drug commonly used in treating herpes virus infections?

Answer 9

Aciclovir - Activated by viral enzyme thymadine kinase therefore only active in affected cells. Activated drug inhibits DNA polymerase

Question 10

Define the term ‘latency’?

Answer 10

Viral infection of a cell without evidence of replication

Question 11

Describe the basic characteristics of all the viruses within the herpesviridae family?

Answer 11

ALL double stranded DNA
ALL enveloped
ALL have latency within their life-cycle

Question 12

Describe the transmission and infection course of varicella-zoster virus?

Answer 12

Respiratory route transmission
Primary infection leads to replication in lymph nodes (primary viraemia) and is transported to the liver and spleen (secondary viraemia)
Dissemination = chicken pox (primary infection)
Latency = dorsal route ganglion
Reactivation = Zoster (shingles)

Question 13

Describe the rash associated with VZV?

Answer 13

Centipedal distribution - all lesions at different stages of development

Question 14

Name six complications associated with varicella-zoster virus?

Answer 14

Bacterial sepsis - (Varicella)
Varicella pneumonia - (Varicella)
Varicella encephalitis - (Varicella)
Congenital varicella syndrome - (Varicella)
Post-herpatic neuraligia - (Zoster)
Opthalmic zoster (CN-V = Nasocilliary branch) - (Zoster)

Question 15

Describe the epidemiology of varicella-zoster virus?

Answer 15

Varicella - 90% seroprevelance

Zoster - 25% of individuals re-activate