The level of infection with herpes simplex virus type 2 (HSV-2), the type more commonly associated with genital herpes, decreased significantly in the United States in the 1990s, particularly in adolescents and males, according to the results of research presented at the latest National STD Prevention Conference (8-11th March, Philadelphia).

The researchers assessed data from two major surveys to examine the trends in levels of HSV-2 infection. The first National Health and Nutrition Examination Survey (NHANES) was carried out between 1988-1994, involving 9165 individuals, while the second took place five years later (between 1999-2000) and involved 3590 subjects.
All participants were given blood tests to determine whether they had been infected with the HSV-2 virus. The first survey found a prevalence of 21.3%, but this had dropped to 17.6% for the second rounds in 1999-2000, a significant overall decrease of 17% between the two surveys. The most marked decreases were in younger age groups, with a 74% decrease in 14-19 year olds and a 48% decrease in 20-29 year olds, and in males with a 35% decrease.

These findings are consistent with data from behaviour surveys which suggest that adolescents have modified their sexual behaviour and thus reduced the risk of being infected with HSV and other sexually transmitted infections.

Reference:
Trends in Herpes Simplex Virus Type 2 Infection in the United States
F Xu, G McQuillan, B Kottiri, M Sternberg, F Lee, A Nahmias, L Markowitz
Presented at 2004 National STD Prevention Conference, 8-11 March 2004, Philadelphia, Pennsylvania