Genital herpes infection: a review

Genital herpes infection is life-long and may result in painful and recurrent genital lesions, systemic complications, serious psychosocial morbidity, and rare but serious outcomes in neonates born to infected women, including permanent neurological handicap and death. Herpes simplex virus (HSV)-2 is the principal cause, with an increasing proportion of first-episode disease caused by HSV-1. Genital HSV transmission is usually due to asymptomatic viral shedding by people who are unaware that they are infected and clinical screening fails to detect most infections. Type-specific serological assays can distinguish the two viral subtypes, but these are expensive and currently restricted to a few research settings. Most infections are asymptomatic, or cause a mild illness which does not lead to health service attendance; but the limited evidence suggests a rise in disease incidence, perhaps related to a fall in HSV-1 age-specific prevalences. The prevalences of HSV genital infections increase with age and numbers of sexual partners, with higher rates in specific ethnic and low socioeconomic groups. However, infection is not restricted to high-risk populations. Antiviral agents, such as acyclovir, can reduce disease severity, prevent recurrences and shorten periods of viral shedding, but currently there are no effective population control measures. This may change with the advent of HSV vaccines, if their safety and long-term efficacy are confirmed. Possible applications for vaccines may include the suppression of disease and recurrences in patients with genital infections (immunotherapy), the prevention of viral transmission to their seronegative partners, and immunoprevention through vaccinating the latter. Economic evaluations of existing and potential control strategies, age-specific population HSV-1 and 2 seroprevalence studies for targeting future interventions, and cohort studies to elucidate the natural history of HSV-2 infections are needed.