WASHINGTON — Behavioral and demographic factors were more predictive of herpes simplex virus type 2 than were clinical symptoms in a study of 127 adolescents, approximately one-third of whom were infected with the disease.
Data from population-based studies have shown that herpes simplex virus type 2 (HSV-2) most often is acquired by women between the ages of 20 and 29 years, but many of them have no clinical symptoms, said Dr. Kenneth Fife of Indiana University, Indianapolis.
To determine the demographic and behavioral factors associated with HSV-2 infection in young women, Dr. Fife and his colleagues collected data for 4–6 years from 127 adolescents aged 14–18 years at baseline. The researchers presented their results in a poster at the jointly held annual meeting of the Interscience Conference on Antimicrobial Agents and Chemotherapy and the Infectious Diseases Society of America.
Of the study population, 92% were black and 7% were white; 33% were antibody positive for HSV-2 at baseline. Only three participants had a history of clinically diagnosed herpes when they entered the study, and the participants underwent quarterly screening for incident STDs. Each participant kept a detailed behavioral diary for two 12-week periods each year and collected weekly vaginal swab samples during these 12-week periods. At the conclusion of the study, the average age of the participants was 21 years.
“Only increasing age, increased time since sexual debut, and an increased number of lifetime sexual partners were significantly correlated with a positive HSV-2 test,” Dr. Fife noted. The odds ratios for these factors were 1.36, 1.17, and 1.09, respectively.
The researchers found no significant association between a positive test result and recorded clinical symptoms of genital pain or discharge.
Of 121 participants for whom complete behavioral data were available, 67 had previous sera available for HSV-2 antibody testing, and 17 (25%) of these women seroconverted from negative to positive during the course of the study.
The DNA testing for HSV-2 in the study population is ongoing, but preliminary results from 13 women with positive results on PCR tests showed that most of the participants shed virus from the genital tract and most had several positive DNA tests over a single 12-week period.
The study was limited by the use of self-reports, but the results suggest that HSV-2 control programs should include young women because they shed virus frequently despite a lack of clinical symptoms, and early signs of infection may go unrecognized, Dr. Fife said.
The study was supported by a grant to Dr. Fife from GlaxoSmithKline and funding from the National Institutes of Health.