Two viruses that cause genital herpes, herpes simplex virus-1 and -2, decreased in prevalence in the United States during the past 2 decades, according to a new study by the Centers for Disease Control and Prevention in Atlanta published in the Aug. 23/30 Journal of the American Medical Association.
Among some 9,000 people tested between 1988 and 1994, 21 percent had been exposed to HSV-2, which is the main cause of genital herpes worldwide. A similar survey conducted between 1999 and 2004 suggested that 17 percent of U.S. residents had been exposed.
Prevalence of HSV-1, which causes cold sores frequently and genital herpes occasionally, fell from 62 percent during the first study period to 57.7 percent during the second period. However, the proportion of HSV-1–infected people who reported developing genital herpes from the virus rose from 0.4 percent to 1.8 percent.
The study didn’t determine the cause of the decreases in virus prevalence.