Nonoxynol-9 is an inexpensive over-the-counter spermicide; laboratory studies have suggested that it could be a barrier to HIV-1 infection and other sexually transmitted diseases, although previous studies among women have been inconclusive. To clarify the effectiveness of Nonoxynol-9 spermicide, Lut Van Damme from the Institute of Tropical Medicine, Antwerp, Belgium (currently affiliated with CONRAD, Arlington, VA, USA), and colleagues did a randomised trial among HIV-1-negative female sex workers in South Africa, Cte d'Ivoire, Benin, and Thailand.
Data from 765 women were included in the primary analysis. Around a third of women used the spermicide gel an average of three and a half times a day, which was associated with a doubling of HIV-1 infection compared with women using a placebo gel. The main hypothesis for the observed effect was the occurrence of vaginal lesions as a result of intensive Nonoxynol-9 use. Low use of Nonoxynol-9 gel did not increase the risk of HIV-1 infection; there were no differences in incidence of other sexually transmitted diseases between Nonoxynol-9 and placebo gels.
Lut Van Damme comments: "Nonoxynol-9 no longer has a part to play in HIV-1-prevention. Our data show that low frequency use of nonoxynol-9 causes neither harm nor benefit; but that frequent use increases a woman's risk of HIV-1 infection by causing lesions."
In an accompanying Commentary (p 962), David Wilkinson from the University of South Australia, Adelaide, Australia, concludes: "It is vitally important that the global effort to develop an effective vaginal microbicide that reduces the risk of acquisition of HIV (and preferably other sexually acquired infections)
Contact: Richard Lane