Herpes Simplex Virus - HSV

Herpes Simplex Virus - HSV

 

Herpes simplex virus (HSV) occurs worldwide and produces a variety of clinical manifestations, ranging from mild stomatitis to fatal disease.

Epidemiology

  • Incidence 
    • HSV-1 – 70-80% seropositivity in U.S. adults
    • HSV-2 – 10-40% seropositivity in U.S. adults
  • Transmission
    • HSV-1 – oral
    • HSV-2 – sexual

Organism

  • DNA virus
  • Types 1 and 2

Clinical Presentation

  • Manifestations and clinical course of HSV depend on clinical site, age and immune status of host
  • HSV type 2 more often causes recurrent genital herpes episodes than type 1
  • Primary infections are usually longer in duration than reactive infections
  • Common clinical syndromes
    • Gingivostomatitis
    • Recurrent herpes labialis
    • Keratitis
    • Conjunctivitis
    • Vesicular skin eruptions
    • Herpetic Whitlow
    • Aseptic meningitis
    • Primary and recurrent genital herpes
    • Visceral herpes (esophagitis, pneumonitis, hepatitis)
    • Encephalitis
    • Neonatal herpes

Diagnosis

  • Indications for testing
    •  Early diagnosis is important since treatment with antivirals may substantially alter course of HSV infections
      • Untreated herpes encephalitis and neonatal herpes are fatal in 70% of patients, with neurologic sequelae in most survivors
      • Disseminated disease, usually in immunocompromised patients, requires aggressive therapy
  • Laboratory testing
    • Culture and nucleic acid amplification based methods are the most sensitive, specific and timely methods for diagnosis of acute lesions (e.g., vesicles, ulcers, inflammation of mucous membranes)
    • Antigen detection tests for HSV are extremely rapid, but only 80% sensitive in acute vesicular lesions and 60-75% sensitive in resolving lesions or asymptomatic shedding
    • PCR test recommended if:
      • Specimen is likely to have a low viral load (CSF in herpes encephalitis)
      • Cultures are negative
      • Patient has AIDS
      • Patient has recurrent meningitis
      • Infant has suspected neonatal herpes
      • Lesions are several days old and culture will likely be negative
    • HSV antibody titers are not particularly useful for rapid diagnosis of acute infections due to delay in obtaining test results
      • In primary HSV infections, significant IgG or IgM titer elevations do not occur for 10-14 days in mucocutaneous disease and 3-4 weeks in herpes encephalitis
      • In reactivated/recurrent infections, high titers of antibody are already in serum at episode onset and do not change during convalescence

Treatment

  • Suppressive therapy may be useful in treating repeated reactivation infections

Prevention

  • Barrier contraception and daily suppressive therapy recommended to prevent infecting partner with genital herpes

See Also