|
Spermicides, already available for contraception without prescriptions in many
countries, are being studied for their ability to prevent HIV. FHI researchers, for
example, are working with the Ministère de la Santé Publique in Cameroon to examine the
effects of the vaginal contraceptive film containing the spermicide nonoxynol-9 (N-9) in
preventing HIV.
Study participants include approximately 1,300 female sex workers in Yaoundé and Douala,
who are HIV-negative. Participants are divided into two groups -- those who use male
condoms and N-9 film and those who use condoms and a placebo film. They will be followed
for one year. Researchers will also examine the effects of N-9 use on genital ulcers, as
well as its effects on normal microorganisms in the vagina. The study is funded by the
National Institutes of Health (NIH) in the United States.
Previous studies have shown that low levels of nonoxynol-9 inactivate HIV in vitro.
But studies in humans have shown conflicting results. One study of female sex workers in
Kenya found that sponges containing N-9 did not protect against HIV, while an FHI study of
N-9 suppository use among sex workers in Cameroon showed a decrease in HIV infection,
gonorrhea and genital ulcers.1 A second analysis of the
Cameroon data, which separated the effects of condom use and N-9 use, found HIV incidence
declined as N-9 use increased.2 FHI research in Zambia found
that among 110 HIV-discordant couples who consistently used N-9 spermicide, there was a
slightly lower incidence of seroconversion than among couples who did not use N-9
consistently. However, the study is not conclusive, and it remains unclear whether N-9
reduces HIV risks.3
The conflicting findings may be due to different doses of spermicide. FHI studies in
Thailand and the Dominican Republic have shown that high, frequent doses of N-9 cause
irritation and disrupt the cell surface of the vagina.4 The
World Health Organization (WHO) conducted a study on effects of the spermicide menfegol,
and found similar results.5 These effects on the vaginal
mucosa may enhance the transmission of HIV and bacterial STDs.
Because in vitro studies show that the detergent spermicides N-9, benzalkonium
chloride (BZK) and menfegol can inactivate HIV, and because studies in humans demonstrate
that spermicides reduce the incidence of gonorrhea and chlamydia, some health
organizations have recommended spermicides as a choice for STD protection. In the United
States, the New York State Public Health Department recommends a hierarchy of protective
measures women can use against STDs. Male latex condoms are the first choice, followed by
female condoms with spermicide, diaphragm with spermicide, and spermicide alone.
"This is risky," a health department brochure says about using spermicide alone
for protection, "but it's better than doing nothing."
In addition to studies on the ability of current spermicides to prevent STDs, research is
under way to develop new spermicides and delivery systems. Advantage 24, a spermicide that
may be effective for 24 hours, is being studied for its microbicidal properties.
Researchers have investigated the spermicidal effects of mandelic acid, which is extracted
from peach leaves and has been shown in vitro to kill both sperm and trichomonas;
crassulaceae, a family of herbs used by rural women for contraception; carrageenan, a
component of seaweed; synthetic magainins, peptides isolated from the skin of the African
clawed frog; and extract from seeds of Abrus precatorius, commonly called Indian
licorice.
Acceptability
Researchers are examining ways to improve acceptability, including evaluations of the
systems used to deliver spermicides and microbicides. An FHI-sponsored study of family
planning clients in Kenya and Mexico found that women preferred spermicides delivered in
contraceptive film rather than foaming tablets.6 Another
FHI-sponsored study among STD clients in Zambia found that foam was the least popular
delivery system while suppositories and foaming tablets were more acceptable.7
A study of 260 women in Scotland examined the acceptability of the diaphragm with
contraceptive film and found that many women preferred the film but experienced some
irritation and discharge not common among users of spermicide gel.8
PROFAM in Mexico has studied the delivery of spermicides through soft capsules that
dissolve in the vagina. The University of Kentucky in the United States is exploring the
use of slow-releasing pellets for spermicides and microbicides, and Biotek, a U.S.
company, is working on a spermicide that turns into a gel when it comes in contact with
vaginal secretions. A vaginal ring, which would release spermicide for up to 30 days, also
is under study.
-- Barbara Barnett
Footnotes
- Kreiss J, Ngugi E, Holmes K, et al. Efficacy of
nonoxynol-9 contraceptive sponge use in preventing heterosexual acquisition of HIV in
Nairobi prostitutes. JAMA 1992; 268: 477-82. Zekeng L, Feldblum PJ, Oliver RM, et al.
Barrier contraceptive use and HIV infection among high-risk women in Cameroon. AIDS
1993; 7:725-31.
- Feldblum PJ, Weir SS. The protective effect of
nonoxynol-9 against HIV infection [letter]. AJPH 1994; 84(6):1032-34.
- Hira SK, Feldblum PJ, Kamanga J, et al. Condom and
nonoxynol-9 use and the incidence of HIV infection in serodiscordant couples in Zambia. In
press.
- Niruthisard S, Roddy RE, Chutivongse S. The effects of
frequent nonoxynol-9 use on the vaginal and cervical mucosa. Sex Transm Dis 1991; 18:
176-79. Roddy RE, Cordero M, Cordero C, et al. A dosing study of nonoxynol-9 and genital
irritation. Int J STD AIDS 1993; 4:165-70.
- Goeman J, Ndoye I, Sakhom M, et al. Frequent use of
menfegol spermicide vaginal foaming tablets associated with high incidence of genital
lesions. J Infect Dis 1995; 171:1611-4.
- Steiner M, Spruyt A, Joanis C, et al. Acceptability of
spermicidal film and foaming tablets among women in three countries. Int Fam Plann
Perspect 1995; 21(3):104-07.
- Hira SK, Spruyt AB, Feldblum PJ, et al. Spermicide
acceptability among patients at a sexually transmitted disease clinic in Zambia. Am J
Public Health 1995; 85(8): 1098-1103.
- Loudon NB, Barden ME, Hepburn WB, et al. A comparative
study of the effectiveness and acceptability of the diaphragm used with spermicide in the
form of C-film or a cream or jelly. Br J Fam Plann 1991; 17(2): 41-44.
For more information, visit Family Health International's Website at www.fhi.org
Go to FHI's Network |
Copyright