Herpes Simplex

Descriptive text is not available for this image BASICS

DESCRIPTION

  • Vesicular rash primarily located in oral and genital regions
  • Historically, HSV-1 caused infection in the lips, mouth, face, and eyes; HSV-2 in the genitals. Now, primary genital infection with HSV-1 is as common as HSV-2.
  • Wide range of sequelae, impacted by age and immune status of host, whether the infection is primary or recurrent, and the degree of dissemination
  • Viral shedding is greatest in primary infections and lessens with recurrences.

EPIDEMIOLOGY

  • Affects all ages; most HSV-1 is acquired in childhood and most HSV-2 is acquired in young–middle adulthood.
  • Overall decreasing incidence and prevalence with education of safe sex and reduced perinatal exposure. (1)[C]

Incidence

>1 million new cases per year

Prevalence

  • Widespread; 1–25% of adults may shed HSV. Many are unaware of their infection status.
  • 45% of the United States is estimated to be infected with HSV-1 and 14.4% with HSV-2.
  • Prevalence of antibodies to HSV-1 is 90% by adulthood in the general population; 33% of the population infected by age 5 years; 30% of adults have antibodies to HSV-2.
  • According to the WHO, about 417 million people worldwide, ages 15 to 49 years are affected by HSV-1.
  • 400 million people have genital herpes caused by HSV-2.
  • 1 in 5 pregnant women are seropositive for HSV-2.

ETIOLOGY AND PATHOPHYSIOLOGY

  • Enveloped dsDNA viruses from the family Herpesviridae
  • Transmitted by contact with infected skin/secretions during periods of viral shedding, childbirth, or transplacentally.
  • Replication leads to cell lysis and blistering/vesicles; proximal migration via sensory nerve to dorsal root ganglia leads to latency and symptom recurrence

RISK FACTORS

  • Immunocompromised state
  • Atopic eczema, especially in children
  • Unprotected sexual intercourse
  • Occupational exposure in dental professionals (herpetic whitlow)
  • Vertical transmission to the neonate is greatest with primary genital infection; incubation is 5 to 7 days (rarely 4 weeks); cutaneous, mucous membrane, or ocular signs seen in 70%
  • Herpes gladiatorum acquired through high contact sports

GENERAL PREVENTION

  • Avoid contact of active lesions with immunocompromised people, elderly, and newborns.
  • Hand hygiene
  • Avoid kissing, sharing beverages, sharing utensils, and sharing toothbrushes.
  • Genital herpes: avoid sexual contact if active lesions are present, but consistent barrier protection use is advised with known limitations; antiviral therapy to reduce viral shedding.
  • Adult male circumcision reduces transmission to partners.

COMMONLY ASSOCIATED CONDITIONS

  • Erythema multiforme: 50% of cases associated with HSV
  • Herpetic whitlow, herpes gladiatorum, Bell palsy
  • Screen all severe, treatment-resistant, or unusual HSV for concurrent HIV infection.

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