Seroprevalence and Correlates of Herpes Simplex Virus Type 2 Infection in Five Sexually Transmitted-Disease Clinics
January 9, 2003
Herpes simplex virus type 2 (HSV-2) is the main cause of genital herpes and a leading cause of genital ulcer disease throughout the world. Furthermore, there is mounting evidence that HSV-2 facilitates the transmission of HIV. In high-risk settings such as STD clinics, where patients are more likely than the general population to be at risk of both HSV-2 and HIV infection, HSV-2 prevalence data is less than complete.
Project RESPECT was a large randomized controlled trial conducted from July 1993 to September 1996 to determine the seroprevalence and correlates of herpes simplex virus type 2 (HSV-2) in a geographically dispersed population of US STD clinic patients at public clinics in Baltimore, Denver, Long Beach, Newark and San Francisco. All English-speaking patients age 14 and older who came for STD examination and had vaginal intercourse in the preceding three months were asked to participate. Men who identified themselves as homosexual or who had a male sex partner during the preceding 12 months were excluded from the study, as were patients found to be HIV-positive at enrollment. Participants and those who refused were similar in age, racial or ethnic background, and education level, although, compared with those who refused, participants were more likely to be women, to have had an STD at enrollment, and to have been previously tested for HIV.
Of 4,128 total participants, 2,348 (56.9 percent) were male and 1,780 (43.1 percent) were female. The study population was 60.7 percent black, 20.6 percent white, 11.3 percent Hispanic, and 7.4 percent other racial or ethnic group. Median age was 25 years (range 14-76 years). Study participants were predominantly low income, and fewer than one-third of respondents had an education beyond high school. All had had at least one sex partner; median number of lifetime sex partners was 10 for women and 20 for men. Median age at first sexual intercourse was 15 years. Almost two-thirds (62.7 percent) of subjects reported prior treatment for at least one STD, with gonorrhea being the most commonly reported past STD.
Overall, 1,686 (40.8 percent) of the 4,128 participants were positive for HSV-2 antibody. HSV-2 seroprevalence was higher among women (52 percent) than among men (32.4 percent). HSV-2 seroprevalence among blacks was 48.1 percent, significantly higher than that among whites (30.1 percent). HSV-2 seroprevalence in Hispanics and other racial or ethnic groups did not differ significantly from that in whites. Black females had the highest overall seroprevalence, 62.8 percent, whereas black males had a seroprevalence of 39 percent, with very little variation by study site, for either black women or black men. White females were 40.8 percent HSV-2 seropositive, whereas white males had the lowest overall seroprevalence, at 19.7 percent. HSV-2 seroprevalence increased with older age and with less education. "Seroprevalence was lowest in San Francisco (33.2 percent) and highest in Baltimore (50.1 percent), with differences largely attributable to the proportion of black participants at each study site," the researchers reported.
Within each racial group, women often had higher rates of HSV-2 than did substantially older men.
The small number of participants less than 17 years old made difficult the determination of the age at which HSV-2 seroprevalence first started to increase. However, among 91 female participants who were 17 years old, HSV-2 seroprevalence was already 33 percent.
Independent predictors of HSV-2 seropositivity included female sex, black race, older age, less education, more lifetime sex partners, prior diagnosis of syphilis or gonorrhea, and lack of HSV-1 antibody. Several variables were available only for women or only for men. Four additional factors predicted HSV-2 infection in women: a prior diagnosis of trichomoniasis, a current diagnosis of trichomoniasis, a history of prostitution, and having a sex partner who had been in jail. The only additional factor predicting HSV-2 infection in men was a history of being in jail. Black women had the lowest median number of lifetime sex partners, yet had the highest overall seroprevalence. Circumcision was not independently associated with HSV-2 infection, after adjustment for other factors. The majority of HSV-2-seropositive persons (84.7 percent) had never received a diagnosis of genital herpes.
These data represent the largest evaluation, to date, of HSV-2 seroprevalence in men and women attending STD clinics. HSV-2 infection is common in STD clinic attendees in the United States, even among young age groups, especially among women. The researchers suggest that efforts to prevent genital herpes should begin at an early age and, ideally, before the onset of sexual activity. The high seroprevalence among blacks, even after adjustment for lifetime sexual exposure, implies that HSV-2 transmission may be influenced as much by sexual network dynamics as by individual risk behaviors, potentially limiting the impact of prevention approaches aimed at changing individual behavior. The high rate of undiagnosed HSV-2 infection likely contributes to ongoing transmission, they conclude, highlighting the need for further evaluation of the risks and benefits of HSV-2 serologic screening as a prevention strategy.
Journal of Infectious Diseases
11.15.02; Vol. 186; No. 10: P. 1381-1389; Sami L. Gottlieb; John M. Douglas, Jr.; D. Scott Schmid; Gail Bolan; Michael Iatesta; C. Kevin Malotte; Jonathan Zenilman; Mark Foster; Anna E. Barón; John F. Steiner; Thomas A. Peterman; Mary L. Kamb, for the Project RESPECT Study Group
This article was provided by U.S. Centers for Disease Control and Prevention. It is a part of the publication CDC HIV/Hepatitis/STD/TB Prevention News Update. Visit the CDC's website to find out more about their activities, publications and services.