HSV-1 cited in genital infections in young women.(Gynecology)

BETHESDA, MD. -- Herpes simplex virus 1 has emerged as an important genital pathogen and is more likely than herpes simplex virus 2 to be the cause of primary genital herpes infections in young women, Sharon L. Hillier, Ph.D., said at a conference on vulvovaginal diseases.

Young, sexually active women are more susceptible to HSV-1 because most do not have protective antibodies to HSV-1 due to the dramatic drop in childhood HSV-1 infections, said Dr. Hillier, director, reproductive infectious disease research, Magee-Womens Hospital, Pittsburgh.

Among the major implications of this trend is the potential utility of the genital herpes vaccine that is being developed, since it targets only HSV-2, and HSV-2 antibodies do not confer protection against HSV-1, she pointed out.

Since estimates of genital herpes from national seroprevalence studies include only HSV-2 infections, they "probably greatly underestimate" the amount of U.S. cases, Dr. Hillier said at the conference, held by the American Society for Colposcopy and Cervical Pathology.

Studies documenting the emergence of HSV-1 as a cause of primary genital herpes infections date to 1990, when HSV-1 was found to have replaced HSV-2 as the most common cause of genital herpes in Scotland. Studies published in 2000 reported that HSV-1 was the cause of 85% of all primary genital HSV infections in Sweden and 70%-90% of all first episodes of genital herpes in women younger than 21 in Norway. In the United States, a 2003 study found that the proportion of newly diagnosed genital herpes infections due to HSV-1 in a university student health service increased from 31% in 1993 to 78% in 2001.

In a recent study, Dr. Hillier and her associates found only 29% of a sample of college students at a University of Pittsburgh student health clinic had antibodies to HSV-1, making the majority susceptible to infection. The study enrolled 1,207 women aged 18-30 years at three different health clinics and found that the HSV-1 seroprevalence was 46.6% overall, but 60% at the primary ...