To estimate the sex-specific effect of herpes simplex virus type 2 (HSV-2) on the acquisition of HIV infection.Background:
The increased number of longitudinal studies available since the last meta-analysis was published allows for the calculation of age- and sexual behaviour-adjusted relative risks (RR) separately for men and women.Design:
Systematic review and meta-analysis of longitudinal studies.Methods:
PubMed, Embase and relevant conference abstracts were systematically searched to identify longitudinal studies in which the relative timing of HSV-2 infection and HIV infection could be established. Where necessary, authors were contacted for separate estimates in men and women, adjusted for age and a measure of sexual behaviour. Summary adjusted RR were calculated using random-effects meta-analyses where appropriate. Studies on recent HSV-2 incidence as a risk factor for HIV acquisition were also collated.Results:
Of 19 eligible studies identified, 18 adjusted for age and at least one measure of sexual behaviour after author contact. Among these, HSV-2 seropositivity was a statistically significant risk factor for HIV acquisition in general population studies of men [summary adjusted RR, 2.7; 95% confidence interval (CI), 1.9–3.9] and women (RR, 3.1; 95% CI, 1.7–5.6), and among men who have sex with men (RR, 1.7; 95% CI, 1.2–2.4). The effect in high-risk women showed significant heterogeneity, with no overall evidence of an association.Conclusions:
Prevalent HSV-2 infection is associated with a three-fold increased risk of HIV acquisition among both men and women in the general population, suggesting that, in areas of high HSV-2 prevalence, a high proportion of HIV is attributable to HSV-2.