A population based study of herpes simplex virus 2 seroprevalence in rural Costa Rica

Objectives: To determine seroprevalence and determinants of herpes simplex virus 2 ( HSV- 2) seropositivity, in a random sample of a population based cohort of 10 049 women of Guanacaste, Costa Rica, using a highly sensitive and specific serological assay. Methods: Seroprevalence was determined by a type specific HSV- 2 ELISA assay in an age stratified random sample of 1100 women. Univariate and multivariate logistic regression was used to calculate odds ratios and 95% confidence intervals for risk factors of seropositivity. Results: Overall age adjusted HSV- 2 seroprevalence was 38.5% ( 95% CI, 37.5 to 39.5), and it was strongly associated with increasing age ( pT(rend <) (0.0001)), both among monogamous women and women with multiple sexual partners. A greater number of lifetime sexual partners increased the risk of seropositivity, with a 28.2% ( 95% CI, 24.4 to 32.2) seroprevalence among monogamous women and 75% ( 95% CI, 65.6 to 83.0) seroprevalence for those with four or more partners ( OR = 7.6 95% CI, 4.7 to 12.4 pTrend, 0.0001). Barrier contraceptive use was negatively associated with HSV- 2 seropositivity ( OR 0.54, 95% CI, 0.31 to 0.94). Women with antibodies against HPV 16, 18, or 31 were 1.6 times more likely to be HSV- 2 seropositive ( OR 1.6, 95% CI, 1.2 to 2.1). Conclusions: HSV- 2 infection is highly endemic in Guanacaste, even among lifetime monogamous women, suggesting a role of male behaviour in the transmission of the infection. Until vaccination against HSV- 2 is available, education to prevent high risk sexual behaviour and the use of condoms appear as preventive measures against HSV- 2.