Andrews Chap 19-Viral Diseases

Viral Diseases (STD)

Infection Rates

  • Infection Rates in Clinics:

    • 30%–50% for patients attending STD clinics.

    • In sub-Saharan Africa: 60%–95%.

    • Worldwide prevalence is higher in individuals infected with HIV.

Herpes Simplex Virus (HSV) Infection

  • Seroprevalence Data:

    • More individuals are infected than report clinical disease.

    • HSV-1: About 50% report orolabial lesions.

    • HSV-2:

      • 20% asymptomatic.

      • 20% recognize recurrent genital herpes.

      • 60% have lesions they do not recognize as genital herpes (subclinical).

Asymptomatic Individuals

  • Individuals carrying HSV-1 or HSV-2 can still transmit the virus without symptoms.

  • Routine screening for HSV is not recommended for asymptomatic people, except for those with signs or symptoms.

Classification of Herpes Simplex Infections

  • Types: First episode or recurrent.

  • Most initial clinical lesions might actually denote a recurrence rather than a new infection.

Diagnosis of HSV Infections

  • Diagnostic Options:

    • Tzanck smear (less sensitive/specific).

    • Direct fluorescent antibody (DFA) test (rapid results).

    • Viral culture (specific and done mainly for severity).

    • Polymerase chain reaction (PCR) testing (most sensitive and specific).

Oral and Orolabial Herpes

  • Clinical Presentation:

    • Orolabial herpes primarily caused by HSV-1.

    • Herpetic gingivostomatitis is severe in children with high fever, malaise, and painful erosions in the mouth, with blurred vision or severe oral lesions.

    • Initial episodes may require intravenous (IV) acyclovir treatment if symptoms are severe, otherwise oral acyclovir is used.

Management of Herpes Simplex Virus

  • Acute Treatment:

    • Limited efficacy for topical therapies (e.g., tetracaine cream, penciclovir, acyclovir cream).

    • For severe symptomatic recurrences, consider oral antiviral regimens like valacyclovir or famciclovir.

    • Topical corticosteroids combined with oral antivirals can lead to quicker healing.

Herpes Gladiatorum and Related Conditions

  • HSV-1 can spread through wrestling, affecting areas of direct contact. Outbreaks may occur during tournaments.

    • Treatment includes suppressive antiviral therapy for wrestlers with a history of HSV.

Other Specific Infections and Risks

  • Herpetic Whitlow: Infection on fingers, treated with supportive care and antiviral therapy if indicated.

  • Intraurethral or Genital HSV Infections:

    • Symptoms include burning, urination pain, and lesions that mimic non-viral conditions like gonorrhea or non-gonococcal urethritis.

Diagnosis and Treatment of Genital Herpes

  • Genital herpes diagnosis often difficult due to similar presentations on mucosal surfaces (like non-viral STIs).

  • Treatment Options for Initial Infection:

    • Acyclovir, famciclovir, or valacyclovir formulations.

    • Symptomatic management included.

Key Statistics on Transmission

  • Transmission Rates: 5%–10% chance of transmission per year in monogamous couples with one infected partner.

Prevention Strategies

  • Effective prevention methods include:

    • Consistent condom use, avoiding sexual exposure during outbreaks, and suppressive therapy for the infected partner.

Implications for Public Health

  • Regular screening and education about the risks of HSV and its implications, especially for at-risk populations, is essential.