Measurement of human immunodeficiency virus(HIV) incidence among female sex workers in Rwanda is a key part of preparing for HIV prevention trials.

HIV-negative, nonpregnant female sex workers (N =397) were tested for HIV-1, sexually transmitted infections, and pregnancy quarterly for 12 months, and again at a 1-time year 2 visit. Additional women (N=156) were tested for HIV at baseline and 6 to 12 months thereafter in a parallel study.

A total of 19 participants seroconverted during follow-up,with 13 in the first 12 months. The 12-month HIV incidence rate (IR)was 3.5 (95% confidence interval: 1.6, 5.4) per 100 person-years (PY).There was a nonsignificant downward trend from 4.6/100 PY (1.6, 7.7)in the first 6 months to 2.2 (0.1, 4.4) in the second 6 months (IR ratio:2.1 [95% confidence interval: 0.7, 7.8]). The year 2 IR was 2.1 (0.4,3.7), and the HIV IR in the parallel study (in the absence of frequent study visits) was 3.3/100 PY (0, 7.0). HIV testing history, lifetime pregnancies, recent initiation of sex work, gonorrhea, syphilis, and change in reproductive intentions were associated with incident HIV infection. Incidence of pregnancy, herpes simplex virus-type 2,trichomoniasis, gonorrhea, chlamydia, and syphilis per 100 PY were as follows: 26.3 (21.9, 30.7), 8.7 (4.0, 13.4), 16.9 (12.7, 21.1), 12.1 (8.2,15.9), 8.1 (5.1, 11.2), and 6.2 (3.7, 8.7).

The HIV/sexually transmitted infections burden int his group was high. HIV IR was highest in the first 6 months of the cohort, and in the parallel study in which there were no risk-reduction procedures. HIV prevention and family planning interventions are needed.