Seroepidemiology and control of genital herpes: the value of type specific antibodies to herpes simplex virus.

Herpes simplex virus (HSV) type 2 is the main cause of genital herpes infections. Conventional serological techniques cannot discriminate between antibodies specific to HSV types 1 and 2, so these methods cannot be used in the seroepidemiological investigation of genital herpes infections. The discovery of type specific antigens in HSV-1 and HSV-2, most notably glycoprotein G (gG), has been successfully exploited to develop assays for the detection of type specific HSV antibody. The presence of type specific antibodies provides evidence for infection with HSV-1, HSV-2, or both. Tests which detect humoral responses to HSV-2 have been used during the past decade to investigate populations in various countries. Most surveys of general adult populations in the developed world have found a relatively low seroprevalence of HSV-2, although this does differ between countries. Studies of HSV-2 antibody in developing countries have revealed higher rates of infection in adults. People attending sexually transmitted diseases (STD) clinics have higher rates of HSV-2 infection than general populations sampled in the same country. Assays of HSV type specific antibodies have been used in seroepidemiological surveys that include information about demography and sexual behaviour to identify risk factors for HSV-2 infection. The surveys show that people with a large number of sexual partners are at increased risk of acquiring HSV-2 infection and that a high proportion of HSV-2 infections are asymptomatic. Assays of HSV type specific antibody have been used to show that the presence of pre-existing HSV-1 antibody may reduce the severity of genital HSV-2 infection. Such assays have also been used in studies of the transmission of genital herpes. Proposed interventions to counter the spread of genital herpes include targeted education and vaccination programmes. Assays of HSV type specific antibodies may be used to monitor the effectiveness of such policies.