The changing epidemiology of HSV-1 and HSV-2 and implications for serological testing.

An increased prevalence of genital herpes simplex virus (HSV) infection has been documented worldwide. In the USA, the National Health and Nutrition Examination Survey (NHANES), conducted from 1988 to 1994, revealed the seroprevalence of HSV-2 in persons 12 years of age or older to be 21.9%, an increase of 30% in age-adjusted seroprevalence of HSV-2 since the previous survey that was conducted from 1976 to 1980. Several European studies have documented a high prevalence of HSV-2 in antenatal populations. The advent of highly sensitive virological tests has confirmed that HSV-2 is the most common cause of genital ulceration in the developing world. People with a high standard of living may escape oral HSV-1 infection in childhood. Since asymptomatic oral shedding of HSV-1 is common, adults without immunity to HSV-1 who practise oral sex are especially at risk for genital HSV-1 infection. In some European cohorts, HSV-1 has been a more common aetiological agent of primary genital herpes than HSV-2. These patient groups may benefit from the use of HSV-1 in addition to HSV-2 type-specific serology.