Incidence of HIV and HTLV-1 infection among sexually transmitted disease clinic attenders in Jamaica.

Of 970 sexually transmitted disease (STD) patients enrolled at the Comprehensive Health Centre, Kingston, Jamaica, between November 1990 and January 1991, 710 (73%, 333 men and 377 women) were reexamined between January 1992 and July 1993 to estimate the incidence of HIV and HTLV-I infection and to identify risk factors for infection. Of those reexamined, 20% were recruited passively when they returned to the clinic of their own accord, and 80% were recruited actively through field visits to their homes. Passively recruited persons were significantly more likely than active recruits to have had a sexually transmitted disease since enrollment or at their follow-up visit. Seven men and one woman became HIV positive during the period of follow-up. The overall HIV incidence rate was 0.7 per 100 person years (95% confidence interval [CI] = 0.3 to 1.4), 1.4 (CI = 0.6 to 2.8) for men and 0.2 (CI = 0.004 to 0.9) for women. Four of 270 men and 4 of 318 women were HTLV-I positive, an overall incidence of 0.9 per 100 person years (CI = 0.4 to 1.7), 1.0 for men and 0.8 for women. HTLV-I infection was associated with an age of 30 years or older (p < 0.01). The presumed lower transmission probability for HTLV-I may combine with a higher prevalence of HTLV-I in sexual partners to produce similar overall incidence rates for the two infections. The HIV and HTLV-I incidence rates may have been underestimated, because the study subjects who did not return to the clinic may have had a somewhat higher risk. On univariate analysis, there were significant associations between HIV infection in men and drinking alcohol before sex, cocaine use, total number of sex partners, sex with a prostitute since enrollment, ever accepting money for sex, the average number of sex partners per month, bruising during sex, and genital ulcers found on follow-up examination. This analysis needs to be interpreted with caution in view of the small number of seroconverters, which did not allow testing for independent effects in a logistic regression model.