Herpes, Genital

Description

• Chronic, recurrent herpes simplex virus (HSV) type 1 or 2 infection of any area innervated by the sacral ganglia
• HSV-1 causes anogenital and orolabial lesions; HSV-2 causes anogenital lesions.
• Primary episode: occurs in the absence of preexisting antibodies to HSV-1 or HSV-2 (may be asymptomatic)
• First episode, nonprimary: initial genital eruption; preexisting antibodies are present.
• Reactivation: recurrent episodes
• Synonym(s): herpes genitalis

Epidemiology

• Most commonly infected from age 15 to 30 years; prevalence increases with age due to cumulative likelihood of exposure.
• Predominant sex: female > male
• Predominant race: non-Hispanic blacks

Incidence
True incidence is unknown because genital herpes is not reportable. Studies estimate the incidence in the United States to be ~572,000 to 1.6 million new cases per year; highest in 18- to 24-year-olds.

Prevalence

• Overall prevalence of HSV-2 is 10–40% in the general population and up to 60–95% in the HIV-positive population (1).
• Between the ages of 14 and 49 years, the prevalence of HSV-1 in the United States is ~48%, and the prevalence of HSV-2 is ~12%.
• Up to 90% of those who are seropositive lack formal diagnosis.
• Globally, it is estimated that HSV-1 infects 3.7 billion people versus 140 million for HSV-2.

Etiology and Pathophysiology

• HSV is a double-stranded DNA virus of the Herpetoviridae family (1).
• Spread via genital-to-genital contact, oral-to-genital contact, and via maternal–fetal transmission (2)
• Incubation is 4 to 7 days after exposure.
• Risk of transmission is highest when lesions are present.
• Viral shedding is possible in the absence of lesions, increasing the risk of transmission (precautions—abstinence, condom use—may not be followed). Viral shedding occurs intermittently, unpredictably, and more commonly with HSV-2.
• HSV infection increases the risk for HIV.

Risk Factors

• Risk increases with age, number of lifetime partners, history of sexually transmitted infections (STIs—particularly HIV), sexual encounters before the age of 17 years, and partner with HSV-1 or HSV-2.
• Infection with HSV-1 confers 3-fold risk of infection with HSV-2.
• Immunosuppression, fever, stress, and trauma increase risk of reactivation.

General Prevention

• Use barrier contraception and avoid sexual contact when symptoms/lesions are present.
• Abstinence is the only means of complete protection.

Commonly Associated Conditions

Syphilis, HIV/AIDS, chlamydia, gonorrhea, other STIs