Herpes Simplex Virus Type 2

Question 1

Characteristics

Answer 1

• enveloped virus
• linear, dsDNA
• no virion polymerase
• cross-reaction with HSV-1 occurs
• no herpes group-specific antigen
• intranuclear replication —> produces intranuclear inclusion bodies = Cowdry bodies

Question 2

Transmission

Answer 2

• sexual contact in adults

- during passage through the birth canal in neonates “ TORCHES infection”

Question 3

Pathogenesis

Answer 3

• initial vesicular lesions occur on genitals
• the virus then travels up the axon and becomes latent in sensory (Lumbar or Sacral) ganglion cell’s
  »> recurrences are less severe than the primary infection

HSV-2 infections in neonates can be life-threatening because neonates have reduced cell-mediated immunity
»> asymptomatic HSV-2 in the female genital tract is an important contributing factor to neonatal infections

Question 4

Disease

Answer 4

Herpes genitalis —> painful inguinal lymphadenopathy with red vesicles

Aseptic meningitis —> in adolescents and adults

Neonatal infection

Question 5

Microbiological diagnosis

Answer 5

• virus causes CPE in cell culture
• identified by antibody neutralization or fluorescent antibody test
• Tzanck smear reveal multinucleated giant cell but is not specific for HSV-2
• a rise in antibody titer can be used to diagnose a primary infection but no recurrences

Question 6

Treatment and prevention

Answer 6

Treatment:

• Acyclovir is useful in treatment of primary and recurrent genital infections as well as neonatal infections
  »> it has no effect on the latent state

Prevention:

• no vaccine
• primary disease can be prevented by protection from exposure to vesicular lesions
• recurrences can reduced by the long-term use of oral acyclovir
• neonatal infection can be prevented by delivering the child by cesarean section if the mother has visible vesicular lesions in the birth canal