From HSV-2 to HSV-1: A change in the epidemiology of genital herpes

Genital herpes (GH), historically associated with herpes simplex virus type 2 (HSV-2), is changing its etiology. Since the last few decades, there has been an increase in genital infections caused by herpes simplex virus type 1 (HSV-1). In fact, in several countries, preferably in high-income regions such as North America or Western Europe, HSV-1 has become the leading cause of first-episode GH, especially among adolescents and young adults. However, the epidemiological trend varies geographically, with slower changes observed in Africa, Latin America, and Southeast Asia, where GH HSV-2 remains dominant. This epidemiological shift may be mainly due to the decline in HSV-1 seroprevalence, decreased childhood exposure to the virus, and changes in sexual practices. Despite the global decline in HSV-1 seroprevalence, GH caused by HSV-1 is rising by 1-2% annually in many areas. This review summarizes the seroprevalence of HSV-1/-2 worldwide in recent decades and discusses the changes in GH etiology and contributing factors. Despite the substantial global burden of the disease and its psychosocial impact, no vaccine or curative treatment exists. Active surveillance, health and sexual health education, and targeted interventions are vital to manage this changing landscape and to mitigate the public health issue posed by GH and HSV-1.