It doesn't mean genital herpes isn't a problem. About one in six Americans (17%) had the genital herpes virus -- called HSV-2 -- during 1999-2004. But that is down from the 21% rate seen in 1988-1994.
The good news comes from a CDC study based on actual blood samples. It provides evidence supporting recent studies documenting self-reported reductions in high-risk sex among teens.
Genital herpes is a highly contagious infection usually spread through intercourse with a person with infected sores, but it can be passed through oral or anal sex as well. It may also be spread even when sores are not visible.
Because herpes infection never goes away, a drop in the nationwide infection rate means that fewer young people are getting HSV-2 infections, note CDC researcher Fujie Xu, MD, PhD, and colleagues.
The study suggests that the upwards trend in genital herpes has been reversed, Xu and colleagues conclude.
Specific behaviors that may have affected genital herpes rates include more careful partner selection, increased use of condoms, and choosing oral sex over vaginal sex.
Genital Infections With Cold-Sore Virus
As its name suggests, HSV-2 isn't the only herpes virus out there. HSV-1, the virus that causes cold sores, is much more common. As of 1999-2004, 57.7% of Americans carry the virus -- down slightly from the 62% HSV-1 infection rate seen in 1988-1994.
There's some bad news here: HSV-1 is causing more genital herpes than ever before. About 2% of people with HSV-1 infection -- but not HSV-2 -- have genital herpes.
"Our findings are consistent with previous reports that genital herpes caused by HSV-1 may be increasing in the United States, as in other developed countries," Xu and colleagues note.
The researchers warn that the herpes virus that causes cold sores may one day become a more important cause of genital herpes. One factor: The increase in teen oral sex that's helping stop HSV-2 spread may be increasing genital infections with HSV-1.
Xu and colleagues report their findings in the Aug. 23/30 issue of The Journal of the American Medical Association.
SOURCES: Xu, F. The Journal of the American Medical Association, Aug. 23/30, 2006; vol 296: pp 964-973.
By Daniel DeNoon
Reviewed by Michael Smith