Seroprevalence of herpes simplex 1-2 antibodies in Brazil.

Objective: To estimate the seroprevalence of HSV-1 and HSV-2 antibodies in Brazil and to analyze factors associated.

Methods: Cross-sectional study including subjects aged 1-40 years from the general population in four different geographical areas in Brazil between 1996 and 1997. All subjects were stratified by age and gender and 1,090 of them were included in the final analysis. Blood samples were tested for HSV-1 and HSV-2 antibodies by type-specific (gG1 and gG2) ELISA. Frequencies and proportions were described and compared among groups using two-sided Fisher's exact test. A logistic regression analysis was performed to assess the influence of the variables age, gender, geographical area, socioeconomic condition, past history of STD, seropositivity for anti-HSV-1 or anti-HSV-2 and interactions of any of these factors on the seroprevalence of HSV-1 and/or HSV-2.

Results: The age-adjusted seroprevalences of HSV-1 and HSV-2 antibodies were 67.2% and 11.3%, respectively, without sex differences and being higher in the North region. Seroprevalences increased with age and, for HSV-2 infection, the higher increase was observed among adolescents and young adults. Subjects who tested positive for HSV-1 were more likely to also test positive for HSV-2 (15.7%) compared to HSV-1 negative subjects (4.7%). In the multivariate analysis past history of STD significantly (OR=3.2) increased the likelihood of HSV-2 infection whereas socioeconomic condition did not affect the results.

Conclusions: HSV-1 and HSV-2 seroprevalences vary with age and among Brazilian regions. Past history of STD is a major risk factor for HSV-2 infection.