Effect of nonoxynol-9 gel on urogenital gonorrhea and chlamydial infection: a randomized controlled trial

Abstract

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 Yaoundé, 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% CI, 1.0-2.3) and for chlamydial infection was 1.0 (95% CI, 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.