Nonoxynol-9 Ineffective in Preventing Transmission of HIV/AIDS

from http://www.who.int/en/

28 June 2002 | GENEVA -- Spermicides containing nonoxynol-9 do not protect against HIV infection and may even increase the risk of HIV infection in women using these products frequently, according to a WHO report released today. The report also advises women at high risk of HIV infection against using nonoxynol-9 spermicides for contraception.

The report contains the recommendations of a meeting of experts convened by the World Health Organization (WHO) Department of Reproductive Health and Research (RHR) and the CONRAD Program* based in the Eastern Virginia Medical School. The experts also concluded that spermicides containing nonoxynol-9 do not protect against two other common sexually transmitted infections – cervical gonorrhoea and chlamydia.

Nonoxynol-9 is present in most spermicides on the market today. It has been used over the past half-century in a wide range of spermicidal products—vaginal gels, creams, foams, suppositories, sponges, and films, used alone or with other contraceptive devices, such the diaphragm. While it had been hoped that these products might reduce the risk of sexually transmitted infections, including HIV infection, they have primarily been used as methods of contraception. Estimated numbers of women of reproductive age using spermicides vary from country to country, from less than 1% in Asia to nearly 17% in some Latin American countries.

"Nonoxynol-9 clearly does not prevent HIV infection and may even favour infection if used frequently. There is an urgent need to develop a microbicide which can substantially reduce the transmission of sexually transmitted infections, including HIV, and which can be used by women," says Dr Tomris Türmen, Executive Director of Family and Community Health (FCH) at WHO.

In the 1970s and 1980s, laboratory tests showed that nonoxynol-9 could inactivate the organisms that cause gonorrhoea, chlamydial infections, and other sexually transmitted infections, as well as HIV. These findings fuelled hopes that it could be used not only for contraceptive but also for microbicidal purposes. Clinical trials conducted to date do not support these hopes.

On the contrary, two studies mentioned in the report point to an increased risk of sexually transmitted infections, including HIV infection, in women using nonoxynol-9 products. A possible reason, suggested by the findings of other studies, is that nonoxynol-9 can disrupt the epithelium, or wall, of the vagina, thereby potentially facilitating invasion by an infective organism.

The frequency of this epithelial disruption seems to depend on the intensity of use of the product—from 18% of women using the product every other day to 53% using it four times a day, in one study. "Women who have multiple daily acts of intercourse should be advised to choose another method of contraception," the experts concluded. However, they added, for women who do not use spermicides frequently and who are not at a high risk of HIV infection, spermicides that contain low doses of nonoxynol-9 are "probably safe".

Dr Henry Gabelnick, Director of CONRAD, emphasied that, "The failure of nonoxynol-9 to provide protection against HIV and other sexually transmitted infections (STIs) should not lead to the conclusion that microbicides are not possible but should instead accelerate research to find safe and effective products."

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