HUMAN-IMMUNODEFICIENCY-VIRUS INFECTION IN MEXICO-CITY - RECTAL BLEEDING AND ANAL WARTS AS RISK-FACTORS AMONG MEN REPORTING SEX WITH MEN

The objectives of this study were to evaluate the frequency and determ inants of rectal bleeding and the association between rectal bleeding and risk of human immunodeficiency virus (HIV) infection among homosex ual/bisexual men in Mexico City. Men who requested anonymous HIV testi ng at a public clinic in Mexico City and who reported engaging in any homosexual behavior were eligible to participate in this study. Traine d staff collected information on demographic factors, sexual behavior, psychological states, and HIV serostatus from all consenting, eligibl e clients, Logistic regression modeling was used to investigate the in dependent effect of risk factors among 2,758 men who were tested betwe en June 1991 and December 1992. Bleeding during anal intercourse was a common occurrence: More than one third of the men in the study report ed some bleeding, and 8% reported bleeding in half or more of their in tercourse episodes. The prevalence of HIV infection among bleeders was 42% as compared with 28% in nonbleeders (p < 0.0001), and the adjuste d odds ratio was 1.8 (95% confidence interval (CI) 1.1-2.8) for men wh o bled in more than half of their anal intercourse episodes relative t o nonbleeders. There was a trend of increasing HIV seroprevalence with increasing frequency of rectal bleeding (p = 0.001). Nine percent of all HIV infections and 42% of infections among frequent bleeders were attributable to rectal bleeding. Men who reported both rectal bleeding and anal warts were 3.5 (95% CI 2.1-5.8) times more likely to be HIV- infected in multivariate analysis than men reporting neither rectal bl eeding nor anal warts. Determinants of rectal bleeding included older age, more education, more receptive anal intercourse than insertive in tercourse, receptive digital-anal contact, anal warts, and genital ulc ers, Among men reporting sex with men in Mexico City, rectal bleeding is common, It is an independent risk factor for HIV infection, and war rants attention in acquired immunodeficiency syndrome prevention effor ts, Rectal bleeding that results from rupture of anal warts may be an especially effective portal of HIV transmission.