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
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