Risk of HIV-1 in rural Kenya: a comparison of circumcised and uncircumcised men.

BACKGROUND Most studies that have found an association between uncircumcised status and infection with human immunodeficiency virus type 1 (HIV-1) have compared participants from various demographic backgrounds, among which the prevalence of other risk factors might have varied. We report findings from a study conducted among men within a single ethnic community in which circumcision was dictated by the religious denomination to which the men belonged. METHODS Of the 1217 eligible men, we included in the analysis 845 who gave blood samples for HIV-1 testing and who were confirmed as either fully circumcised (n = 398) or uncircumcised (n = 447). The seroprevalence of HIV-1 was compared between the 2 groups. RESULTS All correlates of HIV-1 prevalence that we measured were distributed similarly between circumcised and uncircumcised men. The seroprevalence of HIV-1 was 30% among the uncircumcised men and 20% among the circumcised men. Among uncircumcised men, HIV-1 seroprevalence was similar between men from circumcising denominations (31%; n = 111) and noncircumcising denominations (30%; n = 336). The crude prevalence ratio for HIV infection associated with not being circumcised was 1.5 (95% confidence interval = 1.2-2.0); and adjustment for other measured risk factors for HIV-1 infection had little impact on this result. CONCLUSION Our study provides evidence that circumcision is associated with a reduced risk of HIV-1 infection.