Herpes Simplex Virus
from Greek "to creep"
- HSV-1
- generally acquired at early age around mouth
- HSV-2
- generally acquired as STD
- Due to changing habits either type may be found at any given lesion
Structure
- dsDNA , large enveloped virus
- "Fried egg" appearance in EM
Transmission
- virus secreted in vesicle fluid, saliva, vaginal secretions
- disease initiated by direct contact
- may get autoinfection into eye
Clinical Features
- classically give clear vesicle on erythematous base
- progresses to pustular lesions, ulcers, crusting
- establishes latency in dorsal root ganglia and may reactivate
Diseases
- Primary herpes gingivostomatitis
- Herpes labialis - recurrence of infection, "cold sore"
- Herpetic keratitis - eye infection
- Herpetic whitlow - infection of finger
- Herpes gladiatorum - infection of body
- Eczema herpeticum - in children with
active eczema
- Genital herpes - primary infection gives more severe illness
- Herpes encephalitis
- HSV meningitis
- self-limiting
- most often complicates genital HSV-2 infection
- Neonatal HSV infection
Differential Diagnosis
Laboratory Diagnosis
- Microscopic examination of cells from bottom of lesions
- cytopathological effects (CPE)
- cell culture
- CPE in 1-3days (HeLA cells)
- immunoflourescence / ELISA of smear
- PCR / in situ DNA probes
Pathology
- direct cytopathological effects
- cell-to cell spread
- latency in neurons
- reactivation by stress / immune suppression
- cell-mediated immunity required for resolution
Treatment
- Acyclovir (valacyclovir,
penciclovir, famciclovir, ganciclovir)
- vidarabine, idoxuridine, trifluridine - less effective
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