Pm. Coplan et al., HUMAN-IMMUNODEFICIENCY-VIRUS INFECTION IN MEXICO-CITY - RECTAL BLEEDING AND ANAL WARTS AS RISK-FACTORS AMONG MEN REPORTING SEX WITH MEN, American journal of epidemiology, 144(9), 1996, pp. 817-827
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.