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In today's global health village, the term "reproductive health" involves
preventing not only unintended pregnancy, but also sexually transmitted diseases (STDs).
The specter of HIV infection has made protection from genital tract infection a high
priority on the world's reproductive health agenda.
As awareness of HIV and other STDs has grown, decisions about contraceptive use have begun
to involve the need to prevent STDs. This became most obvious at the United Nations 1994
International Conference on Population and Development in Cairo, which defined a
reproductive health agenda that encourages family planning programs to add STD prevention
services. However, the only contraceptives currently recommended for STD/HIV prevention
are barrier methods, making them important for ensuring one's reproductive health.
Nonetheless, many in family planning programs are hesitant to recommend barrier methods
because their record in preventing unintended pregnancies is less reliable than other
contraceptives. Some family planning clinicians worry that reliance on barrier methods
alone will produce higher rates of both unintended pregnancy and STD/HIV. Are their fears
justified?
What do we currently know about the efficacy of barrier methods in preventing STD/HIV?
Four key questions dominate the barrier contraceptive method research agenda. Let us
consider them in order.
Question: Do condoms (male and female) really work to
prevent STD and unplanned pregnancy?
Answer: The simple answer is yes, if used consistently and correctly. When used
consistently, condoms are effective in preventing both STDs and unplanned pregnancy. Thus,
the method itself is effective against both conditions.
Several convincing studies demonstrate the effectiveness of condoms when used
consistently. One intriguing study involved U.S. Navy seamen on shore leave in a
"high- risk" port city: None of the 29 men who reported using condoms with
commercial sex workers became infected with gonorrhea or nongonococcal urethritis, but 14
percent of the nonusers became infected (71 of the 499 nonusers). A second excellent
study of condom use occurred among HIV-discordant couples in Europe. None of the 123
seronegative partners prospectively reporting consistent condom use became infected. Thus,
used regularly and correctly, condoms work effectively.
The problem is that condoms -- whether male or female devices -- are typically used
sporadically or incorrectly. Effectiveness rates must take this into account. Using a
public health model, sexual abstinence will obviously prevent all of the risk of
unprotected sex. However, intercourse using barrier methods of contraception, while not
perfect, also provides a large measure of protection against the risk of STD or unintended
pregnancy. In fact, plotting both abstinence and condom use on the same curve, sex
protected by barrier methods reduces 70 percent of the total risk between unprotected sex
and complete sexual abstinence. Thus, at the policy level, condoms must continue to be
emphasized and made available.
Question: How effective are spermicidal nonoxynol-9 (N-9)
agents against HIV and the other STDs?
Answer: Based on data from well-conducted randomized controlled trials,
spermicides containing N-9 show a measurable protective effect against specific STDs --
gonorrhea, chlamydia, trichomoniasis, and bacterial vaginosis. In Cameroon, Thailand and
the United States, the regular use of N-9 by women attending either STD or family planning
clinics reduced cervical gonorrhea and chlamydia infections by 20 percent to 50 percent.
However, the effect of N-9 agents on HIV transmission remains uncertain. Despite the in
vitro activity of N-9 against HIV, and its protective effect against the simian
immunodeficiency virus in Rhesus monkeys, published data are unclear about the impact of
N-9 on humans in vivo. Among commercial sex workers in Nairobi, women who were randomly
assigned to use a contraceptive sponge with N-9 had higher levels of vaginitis, genital
ulcers, and HIV infection than those using a placebo. However, other observational studies
in Africa and Asia show more favorable results -- HIV infection was reduced among N-9
users. Thus, these data inconsistencies mean the jury is still out on the scientific
verdict regarding N-9 and HIV.
Carefully controlled studies are also needed to assess the relative value of the different
formulations of N-9 in preventing the transmission of STDs, especially HIV. Ongoing
studies of N-9 film in Cameroon, and N-9 gel in Kenya and other parts of the world, will
help resolve the question of which formulation, if any, works best.
Question: How close are we to having another
female-controlled chemical barrier method?
Answer: Because of the uncertainties about N-9, and the desire to have a
microbicide without spermicidal properties, developmental research is under way to
discover new microbicidal agents (see article on page 15). Research is addressing not only
new chemical methods, but also new physical barrier methods that protect the cervix.
New chemical methods under study include a buffer gel that maintains a low vaginal pH and
does not disturb the normal vaginal flora; sulfated polysaccharides designed to prevent
adherence of HIV and chlamydia to cells in a woman's reproductive tract, yet are not
spermicidal; N-docosanol, an antiviral product that works by inhibiting lipid-enveloped
viruses; C31G, an amphoteric surfactant that disrupts cellular membranes but causes less
irritation to the epithelium than N-9; and squalamine, a steroid-based compound that
affects cell growth. These and other agents will undergo phased clinical studies over the
next several years.
Question: Why not emphasize two methods, one for preventing
unintended pregnancy and the other for preventing STD/HIV?
Answer: Clinicians promoting dual contraceptive use must weigh the interacting
factors of extra cost and effect on user compliance. Clients usually attach different
priorities to preventing either pregnancies or infections, and these priorities may change
over time and among relationships.
Studies on dual- method use are limited and have focused on the use of the male condom
added to the mix of other methods of contraception. In general, based on investigations
where participants were using primary methods other than the condom, the more effective
the primary contraceptive was in preventing pregnancy, the lower the level of consistent
condom use. For example, a study in the U.S. city of Baltimore showed only 6 percent of
the women who were sterilized were also using condoms consistently to prevent STDs.
Several reasons can explain why condom use may be low among people already using an
effective contraceptive method. First, many people -- even those with sexual behaviors
putting them at risk of STD -- see pregnancy as a greater immediate threat. Thus, having
taken precautions against unintended pregnancy, they may be less motivated to undergo the
extra effort and expense of using condoms.
Second, those who are sterilized or who are using implants, injectable contraceptives, or
IUDs do not have frequent reminders to use contraception. People who depend upon barrier
methods or the daily schedule of taking oral contraceptives may be more aware of, and
prepared for, prophylactic needs. Without regular reminders of the need to protect against
both pregnancy and STDs, individuals may be less likely to have condoms available.
The way in which counselors and clinicians encourage dual methods can influence whether
the message is effective. With spermicides as the primary contraceptive method, the
percentage of consistent condom users varied dramatically among three small clinic-based
studies in Mexico, the Dominican Republic, and Kenya. This indicates factors other than
the method itself affect levels of concurrent use.
In addition, among Colombian commercial sex workers, women counseled to use spermicides as
a backup method if their clients were unwilling to use condoms were less likely to use
condoms consistently than women encouraged only to use male condoms. More research is
clearly needed on the best mix of contraceptives. Studies that examine the use of the
female condom, diaphragm, or spermicides in conjunction with long-term methods will help
clarify this issue.
What are the key messages regarding use of barrier contraceptive methods to achieve better
reproductive health? First, encourage correct and consistent use of condoms. Second,
maintain hope (albeit with appropriate scientific skepticism) that research will show N-9
can be used effectively against HIV. Third, support developmental research of other
female-controlled contraceptive barrier methods and microbicides. Fourth, evaluate ways to
increase dual-method use to prevent both unplanned pregnancies and STD/HIV.
Dr. Cates, FHI's corporate director for medical affairs, is an epidemiologist. He
previously directed the Division of STD/HIV Prevention at the U.S. Centers for Disease
Control and Prevention.
For more information, visit Family Health International's Website at www.fhi.org
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