Herpes Simplex at a Glance
- Herpes simplex viruses (HSVs) are common human DNA viral pathogens that intermittently reactivate. After replication in the skin or mucosa, the virus infects the local nerve endings and ascends to the ganglia where it becomes latent until reactivation.
- There are two types of HSV: HSV-1 and HSV-2. HSV-1 is mostly associated with orofacial disease, whereas HSV-2 usually causes genital infection, but both can infect oral and genital areas and cause acute and recurrent infections.
- Most of the adult population is seropositive for HSV-1, and the majority of infections are acquired in childhood. About one-fourth of adults are infected with HSV-2 in the United States. Acquisition of HSV-2 correlates with sexual behavior.
- Most primary HSV infections are asymptomatic or not recognized, but they can also cause severe disease. Most recurrences are not symptomatic (asymptomatic shedding), with most transmissions occurring by asymptomatic shedding.
- Genital herpes is the most prevalent sexually transmitted disease worldwide and is the most common cause of ulcerative genital disease, and it is an important risk factor for acquisition and transmission of human immunodeficiency virus.
- HSV can cause diseases involving the eye, central nervous system, and neonatal infection. Cellular immunity defects are a risk factor for severe and disseminated disease.
- Diagnosis is made by polymerase chain reaction, viral culture, or serology, depending on the clinical presentation.
- Treatment is with acyclovir, valacyclovir, or famciclovir. Regimens and dosages vary with the clinical setting. Resistance is rare in other than immunocompromised patients.
Herpes simplex virus (HSV) infections are common worldwide and are caused by two closely related types of HSV. Their main clinical manifestations are mucocutaneous infections, with HSV type 1 (HSV-1) being mostly associated with orofacial disease, whereas HSV type 2 (HSV-2) is usually associated with genital and perigenital infection.
The incidence of primary infection with HSV-1, which is responsible for the vast majority of recurring labial herpes, is greatest during childhood, when 30%–60% of children are exposed to the virus. Rates of infection with HSV-1 increase with age and reduced socioeconomic status, the majority of persons age 30 or older are seropositive for HSV-1.1,2 From 20% to 40% of the population have had episodes of herpes labialis.3 The frequency of recurrent episodes is extremely variable, and, in some studies, averages about once per year,4 but there is evidence that the frequency and severity of recurrent HSV-1 disease decrease over time.
Acquisition of HSV-2 correlates with sexual behavior and the prevalence of the infection in the pool of one's potential sexual partners. Antibodies to HSV-2 are rare in people before the onset of intimate sexual activity and rise steadily thereafter. HSV-2 seroprevalence in the United States is 22% in persons 12 years of age or older.5 The rate of HSV-2 seropositivity declined in the United States from 21% in 1988–1994 to 17% in 1999–2004, and rate of HSV-1 seropositivity declined from 62% to 58% during ...