HHV1&2

Question 1

Structure of herpes viruses?

Answer 1

i1. 100-180nm diameter
2. icosahedral
3. ether sensitive outer membrane
4. dds DNA

Question 2

what happens to herpes viruses after primary infection?

Answer 2

Sequeste into sites where they remain quiescient. viral reactivation leading to recurrent infection may be triggered by factors like immunosuppression

Question 3

HSV1 vs HSV2
a) primary site
b) reaction with antisera
c) plaques in chick embryo monolayer
d) restriction pattern of viral DNA
e) viral polypeptide
f) transformation of hamster cells

Answer 3

a) Lips vs Genitalia
b) HSV1 antisera vs HSV2 antisera
c) - vs +
d) HSV1 pattern vs HSV2 pattern
e) HSV1 vs HSV2
f) + vs +

Question 4

features common to both HSV1 and HSV2?

Answer 4

vesicular eruption - blisters = virus infects cells, cells lyse and collect under skin (skin itself unaffected bc those are dead cells and virus needs living cells to hijack host machinery)
encephalitis
early inclusion - cowdy type A inclusion body

Question 5

where does HSV1 and HSV2 persist latently?

Answer 5

travels to sensory ganglia

Question 6

Clinical features of HSV1?

Answer 6

1. Acute Herpetic Gingivostomatits
   -vesicles on buccal mucosa, gums ulcerate with grey slough
   - fever, lymphadenopathy
2. Herpes Labialis (vesicles at mucocutaneous junction of lips or near nose)
3. Herpetic Whitlow (implantation into fingers = lesions with serois exidate
4. Eczema herpeticum (superinfection of chronic eczematous skin with extensive vesiculation, fever and mortality
5. Keratoconjunctivitis
6. Aseptic Meningitis
7. Acute necrotising encephalitis
8. Disseminated Herpes in immunocompromised subjects (ie herpes hepatitis)

Question 7

Clinical features of HSV2?

Answer 7

1. Herpes Progenitalis
2. Neonatal Herpes
   - jaundice, hepatosplenomegaly, thrombocytopenia, large cutaneous vesicles
3. Cervical & vulvar carcinomas (stronger association with HPV 16 & 18)

Question 8

When are HSV1 and HSV2 acquired? How are they spread?

Answer 8

1. Early in life, 100% have antibodies by adulthood
   HSV2 around puberty

Question 9

Diagnosis of HSV1 & 2?

Answer 9

1. Virus Isolation
2. Inoculation of Cell Cultures - CPE of rounded cells, NT or IF with specific antigens
3. Scrapings = multinucleated giant cells (Tzanck cell microscopy)

Question 10

serology of HSV

Answer 10

primary HSV = neutralising HSV IgM ab; significant rise in Ab titre 2-4weeks after primary infection

recurrent infection = high levels of existing ab, no rise in titre