How well do condoms prevent acquisition of genital herpes?

These US authors identified prospective studies with individual-level condom use data and laboratory-defined HSV-2 acquisition for a pooled analysis of infection transmission. They included 6 studies-3 candidate HSV-2 vaccine studies, an HSV-2 drug study, an observational sexually transmitted infection (STI) incidence study, and a behavioral STI intervention study. Effect of condom use was modeled using a continuous percentage of sex acts during which a condom was used and, alternatively, using absolute numbers of unprotected sex acts.They found: "A total of 5384 HSV-2-negative people at baseline contributed 2 040 894 follow-up days, 415 persons acquired laboratory- documented HSV-2 during follow-up. Consistent condom users (used 100% of the time) had a 30% lower risk of HSV-2 acquisition compared with those who never used condoms (hazard ratio HR, 0.70). Risk for HSV-2 acquisition increased steadily and significantly with each unprotected sex act (HR, 1.16). Condom effectiveness did not vary by gender."The authors concluded: "To our knowledge, this is the largest analysis using prospective data to assess the effect of condom use in preventing HSV-2 acquisition. Although the magnitude of protection was not as large as has been observed with other STIs, we found that condoms offer moderate protection against HSV-2 acquisition in men and women."

It is not surprising that condoms are less protective against HSV-2 acquisition, since perineal contact can be enough for transmission.

For the full abstract, click here.

Arch Intern Med 169(13):1233-1240, 13 July 2009

© 2009 to the American Medical AssociationA Pooled Analysis of the Effect of Condoms in Preventing HSV- 2 Acquisition. Emily T. Martin, Elizabeth Krantz, Sami L. Gottlieb, et al.