Investigators at Family Health International (FHI), a nonprofit health
research organization based in the United States, collaborated with
at the Cameroon Ministry of Public Health to conduct this study with
sex workers in two cities in Cameroon. Of the 1,292 women who enrolled,
941 completed 12 months of follow-up. Volunteers were given
films to be used before sexual intercourse. The films contained either
spermicide nonoxynol-9 (N-9) or a placebo. The women were supplied with
male latex condoms and counseled monthly about reducing their number of
partners and other safe sex practices. They also were examined and
monthly for any STDs.
Preliminary analysis of the results from this recently completed study
showed the overall rate of HIV transmission to be 6.7 percent, half the
transmission rate that was previously estimated in this population.
This rate reduction was the same in both the N-9 film users and the
"We are encouraged by the apparent effectiveness of the overall
intervention program that included counseling, STD treatment and
encouragement of condom use," says Rodney Hoff, Ph.D., chief of
the Efficacy Trials Branch in the AIDS Vaccine Research and
Prevention Program. "Correct and consistent condom use is highly
effective, but women must depend on the willingness of their partners
to use male condoms. We and other public health officials are committed
to developing an STD/HIV prevention method that can be controlled by a
woman. This study is one part of that ongoing effort."
The search for woman-controlled methods has focused on the development
of virus- and bacteria-killing products that women can apply
before having sex. Known collectively as topical microbicides, these
could give women the means to protect themselves from STDs.
"We had hoped that the N-9 film might increase a woman's available
for HIV and STD protection," says Willard Cates, Jr., M.D., M.P.H.,
senior vice president for biomedical affairs. "These results show that
must accelerate our research programs dedicated to finding new products
and techniques for women to use."
Until safe and effective vaginal microbicides are developed, the Centers
Disease Control and Prevention (CDC) recommends consistent and correct
use of male latex condoms, with or without the use of a spermicide, to
prevent sexual transmission of HIV and other STDs in high-risk
The CDC does not currently recommend the use of spermicides alone.
The agency will continue to monitor data from this and other studies of
vaginal products with N-9 to determine if their use results in
benefits or adverse effects.
N-9 is a detergent-like chemical that has been widely used for more than
30 years in over-the-counter gels, foams, creams and films designed to
sperm. Researchers have shown that N-9 can kill HIV and other STD
microbes in laboratory experiments. Previous studies in small numbers
of women suggested that N-9 had some benefit as a topical microbicide,
but also prompted some concern that frequent use or use of high doses of
N-9 could disrupt the cells that line the genital tract, thereby
chances of HIV infection.
The primary investigators for this study were Ronald E. Roddy, M.P.H.,
FHI and Leopold Zekeng, Ph.D., of the Cameroon Ministry of Health. The
sex workers volunteered at clinics in Yaounde and Douala between March
1995 and December 1996. To be eligible, participants could not be
pregnant, or allergic to latex or to N-9. Of the eligible volunteers,
were randomized into two groups and completed the study. One group of
women were given condoms and contraceptive film containing 70 mg of
and a second group of 463 women were given condoms and film containing
placebo (an inert substance). Neither the women nor the study
knew which product a woman received.
The rates of HIV and other STD transmission were essentially the same
both groups and were measured in woman-years. For every 100 women
using N-9 film and condoms for one year, 6.7 became infected with HIV,
33.3 became infected with gonorrhea and 20.6 with chlamydia. Infection
rates for those provided placebo film and condoms were 6.6 for HIV, 31.1
for gonorrhea and 22.2 for chlamydia per 100 woman-years. Women using
N-9 film and condoms had 42.2 genital sores per 100 woman-years compared
with 33.5 sores in the placebo group. Women in the N-9 film group
147,996 acts of sexual intercourse, and those in the placebo film
Additional funding for this study was provided by the U.S. Agency for
International Development and the Mellon Foundation. The N-9 film was
provided by Apothecus Pharmaceutical Corp. of Oyster Bay, N.Y.
NIAID is part of the National Institutes of Health, an agency of the
Department of Health and Human Services. NIAID conducts and supports
research to prevent, diagnose and treat illnesses such as AIDS and other
sexually transmitted diseases, tuberculosis, asthma and allergies.