Herpes Viruses

Question 1

Are herpesviruses DNA or RNA viruses?

Answer 1

dsDNA linear

Question 2

Are herpesviruses enveloped?

Answer 2

Yes

Question 3

What is the most common cause of sporadic encephalitis?

Answer 3

HSV-1

Question 4

How is HSV-1 transmitted?

Answer 4

Respiratory secretions

Saliva

Question 5

What diseases does HSV-1 cause?

Answer 5

Sporadic encephalitis
Oral/genital lesions
Keratoconjunctivitis

Question 6

What diseases does HSV-2 cause?

Answer 6

Genital/oral lesions

Neonatal herpes

Question 7

Where does HSV-2 reside in the latent stage?

Answer 7

Sacral ganglia

Question 8

What drugs are guanosine analogs used to treat HSV and VZV.

Answer 8

Acyclovir
Famciclovir- herpes zoster
Valacyclovir- pro drug of acyclovir that has better oral availability

Question 9

What is the mechanism of action of acyclovir?

Answer 9

Guanine analog.
Monophosphorylated by HSV/VZV thymidine kinase.
Triphosphate formed by cellular enzymes.
Inhibits viral DNA polymerase.

Question 10

Why does acyclovir have few side effects?

Answer 10

It must be phosphorylated by viral thyidine kinase.

Question 11

What diseases are caused by VZV?

Answer 11

Chicken pox
Shingles (zoster)
Encephalitis
Pneumonia

Question 12

Where does VZV reside in the latent stage?

Answer 12

Trigeminal ganglia

Dorsal root

Question 13

How is VZV transmitted?

Answer 13

Respiratory secretions

Question 14

What is the most common complication of shingles?

Answer 14

Post herpatic neuralgia

Question 15

Characterize the clinical findings of mononucleosis.

Answer 15

Fever
Hepatosplenomegaly
Pharyngitis
Lymphadenopathy- especially posterior cervical

Question 16

How is EBV transmitted?

Answer 16

Respiratory secretions

Saliva

Question 17

How is HSV-2 transmitted?

Answer 17

Sexual contact

Perinatally

Question 18

What is the characteristic histologic appearance of CMV infection?

Answer 18

Owl eye inclusions

Question 19

Where does CMV reside during latency?

Answer 19

Mononuclear cells

Question 20

How is HHV-6/HHV-7 transmitted?

Answer 20

Saliva

Question 21

What disease is caused by HHV-6/HHV-7?

Answer 21

Roseola- high fevers that can cause seizures (days) followed by diffuse macular rash

Question 22

How is HHV-8 transmitted?

Answer 22

Sexual contact

Question 23

What disease is caused by HHV-8?

Answer 23

Karposi sarcoma

Question 24

What is Karposi sarcoma?

Answer 24

Neoplasm of endothelial cells

Question 25

Describe the dermatologic findings of Karposi sarcoma.

Answer 25

Dark/violaceous plaques or nodules- represents vascular proliferation

Question 26

How do you identify HSV in a patient with skin/genital vesicles?

Answer 26

Tzanck test- smear of opened skin vesicle to detect multinucleated giant cells

Question 27

How do you identify a herpesvirus in a patient with encephalitis?

Answer 27

CSF PCR

Question 28

Where does encapsidation of herpesviruses occur?

Answer 28

Nucleus- intranuclear inclusions

Question 29

What herpesvirus do heterophile antibodies indicate?

Answer 29

EBV infection

Question 30

What malignancies are associated with EBV?

Answer 30

``` Burkitt lymphoma B-cell lymphoma Leiomyosarcoma Hodgkin lymphoma Nasopharyngeal carcinoma Gastric adenocarcinoma ```