Background: The biological mechanism of circumcision as potentiating HIV prevention is poorly understood. Foreskin microbiota has been postulated as having a potential role; however, little is known about the relationship between bacterial pathogens and circumcision in adults.
Materials and methods: We sampled the coronal sulcus of a diverse group of circumcised and uncircumcised men (n=315) from a government chest hospital and fertility clinic in Hyderabad, Andhra Pradesh, India. Genital examination was conducted on three groups of men: Group 1 - HIV infected; Group 2 - TB infected; Group 3 - control. Aerobic and anaerobic specimens were cultured according to standard clinical protocols, and results were analyzed following multivariate logistic regression models.
Results: Three hundred fifteen study participants - 47.6% of Group 1, 36.5% of Group 2, and 15.9% of Group 3 - were enrolled in the study and included in all analyses. Overall 37.1% of the participants were circumcised without variation across groups (P=0.29). Smegma was observed in 18.7% of the participants with no cases observed in Group 3 (P<0.001). Gram-negative pathogens were more prevalent among study participants in Group 1 (22.7%) and Group 2 (30.4%) as compared with those in Group 3 (6.0%) (P=0.003). In multivariate regression analysis, controlling for group, age, and presence of smegma, uncircumcised men were more likely to be colonized with gram positives [Adjusted Odds Ratio (AOR) 1.9; P<0.05)], gram negatives (AOR 2.4; P<0.05), or any pathogen (AOR 2.8; P<0.005).
Conclusions: Uncircumcised men in this population in South India are more likely to harbor bacterial pathogens in the coronal sulcus than do their circumcised counterparts. Future studies should examine the relationship between foreskin microbiota and HIV transmission.
Keywords: Circumcision; HIV; Staphylococcus aureus; Tuberculosis.