Effect of nonoxynol-9 gel on urogenital gonorrhea and chlamydial infection: a randomized controlled trial. (Original Contribution)

A vaginal gel containing the spermicide nonoxynol-9 does not appear to protect women from gonorrhea and chlamydia infection. This was the conclusion of a study of 1,251 women who used a condom or a condom plus nonoxynol-9.
Context Nonoxynol-9 has been suggested as a vaginal microbicide to protect against common sexually transmitted infections. Objective To compare nonoxynol-9 gel and condom use (gel group) vs condom use alone (condom group) for the prevention of male-to-female transmission of urogenital gonococcal and chlamydial infection. Design and Setting Randomized controlled trial conducted at 10 community clinics and 10 pharmacies in Yaounde, Cameroon, between October 1998 and September 2000, with 6 months of follow-up. Participants High-risk population of 1251 women (excluding sex workers) being treated for or who had symptoms of sexually transmitted infections. Three were excluded from the gel group (0.5%) and 7 from the condom group (1 %) because of no follow-up data. Interventions Nonoxynol-9 gel (100 mg) and condoms or condoms only. Main Outcome Measure A positive test result for gonococcal or chlamydial infection by the ligase chain reaction assay; secondary outcome measure was a positive test result for human immunodeficiency virus (HIV). Results The rate ratio (RR) for new urogenital infections was 1.2 for the gel group vs condom group (95% confidence interval [CI], 0.9-1.6; P=.21). The gel group had 116 diagnosed gonococcal infections, chlamydial infections, or both for a rate of 43.6 per 100 person-years, and the condom group had 100 infections for a rate of 36.6 per 100 person-years. The RR for gonococcal infection in the gel group vs the condom group was 1.5 (95% Cl, 1.0-2.3) and for chlamydial infection was 1.0 (95% Cl, 0.7-1.4). There were 5 new cases of HIV infections in the gel group and 4 in the condom group. Three women in each group became pregnant during the study. Conclusion Nonoxynol-9 gel did not protect against urogenital gonococcal or chlamydial infection.