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Herpes Simplex Virus Testing

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Herpes Simplex Virus Testing, HSV Test, Genital Herpes Diagnosis, HSV Diagnosis, Genital Herpes Screening, HSV PCR, Herpes Simplex Virus Culture, Herpes Simplex Antibody, Herpes simplex serology

  • Indications
  1. Herpes Simplex Virus
  2. Oral Hepes
  3. Genital Herpes
  4. Genital Herpes in Pregnancy
  5. Neonatal Herpes Simplex Virus
  6. Herpes Keratitis
  7. Herpetic Whitlow
  8. Herpetic Sycosis
  9. Herpes Gladiatorum
  10. Erythema Multiforme
  11. HSV Encephalitis
  • Labs
  • Definitive HSV Diagnosis
  1. Sample collection
    1. Unroof Vesicles with scalpel or needle tip and apply viral PCR or culture swab
  2. HSV Polymerase chain reaction (HSV PCR, preferred)
    1. Test Sensitivity: 95% (similar Test Specificity)
    2. Provides more rapid results than viral culture or Direct Fluorescence
    3. Used in HSV Encephalitis diagnosis for rapid results
  3. HSV Viral Culture of vesicular fluid
    1. HSV PCR has much higher Test Sensitivity and is preferred over culture
    2. Culture differentiates HSV I from HSV II
    3. Expect viral growth within 5 days (range 3-10 days)
    4. Test Sensitivity: 50-75% (90% in primary episode)
      1. Vesicles are most concentrated with infection within first 48 hours
      2. Early ulcerative stage may yield a positive result
      3. Not useful in lesions beyond 5 days old
  4. Older tests replaced by HSV PCR
    1. Tzanck Smear of Ulcer scraping
    2. HSV Direct Fluorescent Antibody
      1. Test Sensitivity: 80-90% of viral culture positive
    3. Rapid Giemsa (Dif-Quik) stain
      1. Multinucleated giant cells
      2. Test Sensitivity: 40-77%
  • Labs
  • Presumptive HSV Diagnosis - Type specific HSV Serology
  1. Tests
    1. Initial Testing
      1. HSV Enzyme Immunoassay
    2. Confirmatory
      1. HSV Western Blot
      2. Biokit HSV2 Rapid Test
    3. Older HSV IgG and IgM are out-dated and are not recommended
      1. Glycoprotein G-specific HSV Serology
  2. Incidence of positives
    1. Increased False Negative testing in early HSV infection (consider repeat testing at 12 weeks after exposure)
    2. HSV I: 90% of adults are positive
    3. HSV II: 30% of adults positive
  3. Indications
    1. Confirm HSV where history is questionable
    2. Partners of Genital Herpes patients
    3. High risk patients (multiple sexual partners, HIV positive, HIV Risk Factors)
    4. Recurrent lesions, but negative HSV PCR or culture
      1. More useful if positive Serology for HSV II
      2. Positive Serology for HSV I does not identify infection site (oral or genital)
  4. Disadvantages
    1. USPTF and CDC do not recommend routine use (esp. since HSV I causes >50% of Genital Herpes)
    2. Antibodies form with weeks of primary infection
    3. Does not differentiate acute infection from prior infection
  5. Interpretation
    1. Primary Herpes Simplex Infection may result in a four fold increase in acute over convalescent Antibody titiers
  • Resources
  1. CDC Genital Herpes Screening
    1. http://www.cdc.gov/std/herpes/screening.htm