Nonoxynol-9 use, genital ulcers, and HIV infection in a cohort of sex workers.

ABSTRACT

PIP: To determine whether nonoxynol-9 produces disruption of the genital epithelium and, in turn, places users of this spermicide at increased risk of human immunodeficiency virus (HIV), 273 seronegative female commercial sex workers in Cameroon were enrolled in a 12-month cohort study. Subjects were instructed to use condoms and 100 mg nonoxynol-9 suppositories at each act of intercourse and to maintain coital logs. The presence or absence of vaginal and cervical ulcers was recorded at monthly gynecologic examinations; HIV testing was performed every three months. Included in the final analysis were the 191 women with no cervical ulcers at baseline. Of these, 77 (40%) were classified as frequent (15 times/month) nonoxynol-9 users, 84 (44%) as intermediate (11-15 times/month) users, and 30 (16%) as infrequent (10 or fewer times/month) users. 40 women had evidence of cervical ulceration during the observation period and 18 developed vaginal ulcerations. Unexpectedly, nonoxynol-9 use was not associated with an increased risk of ulceration. The incidence rates for cervical and vaginal ulcers, respectively, were 2.7% and 0.6% among frequent users, 2.2% and 0.8% among intermediate users, and 9.0% and 3.0% among infrequent users. Of the 17 women who became infected with HIV during the study, 29% had experienced ulceration compared to a rate of 28% for matched controls (odds ratio, 1.1; 95% confidence interval, 0.3-3.5). It is speculated that nonoxynol-9 provides sufficient lubrication during intercourse to prevent epithelial trauma. It is further plausible that any ulcers caused by nonoxynol-9--as opposed to those of infectious etiology--lack the immunologic cell responses required to increase susceptibility to HIV.