By Willard Cates, Jr., MD, MPH
President, Institute for Family Health, Family Health International
Male condoms — when used consistently and correctly — are an
effective means of preventing HIV infection, gonorrhea (in men), and
unplanned pregnancy among people who are sexually active and need to
protect themselves. Both a consensus report issued by the U.S. National
Institutes of Health (NIH) in 2001 and a fact sheet released by the U.S.
Centers for Disease Control and Prevention (CDC) in 2002 have recognized
these facts.1
Nonetheless, some observers continue to question the inherent
effectiveness of male condoms.2 Others downplay condoms as an
HIV prevention strategy by exaggerating "condom failure," as
measured by breakage and slippage rates. Because the most important
factor affecting condom failure is non-use3 — not breakage
or slippage — this negative interpretation might discourage condom use
and thus enhance the spread of sexually transmitted infections (STIs).
Amidst these polarized views, we can craft a constructive middle
ground to answer two basic questions:
- Are condoms effective against STIs?
- If so, what is the appropriate role of condoms in strategies to
prevent HIV and other STIs?
The first question involves generating a common interpretation of
data on condom effectiveness. The NIH consensus report and the CDC fact
sheet are clear in this regard: If used consistently and correctly, male
condoms provide protection against HIV (the most serious STI), gonorrhea
(the most easily transmitted STI), and unintended pregnancy. Depending
on the meta-analysis or model used to study condom effectiveness,
consistent use reduces HIV incidence by at least 80 percent and perhaps
as much as 97 percent.4 For protection against unintended
pregnancy, condoms are 86 percent to 97 percent effective, depending on
whether use is typical or ideal, respectively.5 The
scientific evidence to support these conclusions is not complete, but it
is strong and consistent enough to produce the solid public health
recommendation that condoms work. Most HIV/STI transmission or
pregnancy risks likely occur because of condom non-use or inconsistent
use.6 To maximize the consistent use of condoms in sexually
active populations with a high prevalence of HIV/STIs, public health
messages must reinforce and communicate in an unequivocal way the
positive news on condom effectiveness, especially for dual protection
(against both pregnancy and STIs).
Do we need to conduct more research to clarify condom effectiveness
against STIs other than HIV? I would argue "no." The simple
fact that condoms are effective against unplanned pregnancy and HIV
infection will remain the most compelling reason to use them, regardless
of any additional protection they may provide. Meanwhile, it is
important to recognize that the absence of evidence that condoms
provide such additional protection is not evidence of absence of
protection. Given the physical properties of male latex condoms, it is
reasonable to assume that they can be effective against any STI spread
by the exchange of body fluids.
Having established that condoms are effective in reducing unplanned
pregnancy and HIV infection, we must also acknowledge that they do not
work perfectly. What then is the appropriate role of an imperfect
prevention method, like condoms, among strategies to reduce HIV spread?
Those using various approaches to preventing HIV, as well as other
health conditions, recognize that incremental, partially effective steps
work best to produce collectively effective (but not perfect) prevention
programs.7 Controlling the spread of STIs will require
different, mutually reinforcing techniques.
Although these combined prevention strategies can dramatically affect
HIV spread,8 they need to be carefully designed and
implemented. Accurate messages about condoms must build on (and not
substitute for) a wide range of HIV/STI risk avoidance and risk
reduction approaches.9 These approaches include delayed
initiation of sexual intercourse, mutual faithfulness, and selection of
low-risk partners. In Uganda, these approaches, together with condoms,
have been labeled the "ABC strategy": abstinence, be
faithful to one partner, or — if "A" or "B" cannot
be achieved — use condoms. This ABC approach defines an
appropriate role for condoms as an essential part of a larger
armamentarium for HIV prevention. Notably, the components of the ABC
approach need to be balanced. For example, neither an AAAAbc approach
(which overemphasizes abstinence) nor a CCCCab approach (which
overemphasizes condom use) would have an optimal public health impact.
Moreover, our collection of weapons against HIV goes well beyond the
ABC strategy, including potentially effective interventions such as
screening and treatment for other STIs, male circumcision, use of
antiretrovirals for prevention, various approaches to prevention of
mother-to-child transmission (by reducing viral load), screening of
blood products, and needle-exchange programs. The future may also give
us topical microbicides and HIV vaccines, which may not provide complete
protection but can enhance our HIV prevention arsenal. Thus, rather than
the limited ABC message, we should use a broader "ABC to Z"
model to convey the full spectrum of prevention opportunities, of which
consistent use of condoms is only one.
Note: Dr. Cates is an epidemiologist whose public health career
has focused on the interface of contraceptive choice and HIV/STI
prevention. Before joining FHI in 1994, he headed the Division of
STD/HIV Prevention at the CDC for a decade. Dr. Cates delivered the
plenary speech at a recent workshop sponsored by the U.S. National
Institute of Child Health & Human Development about the design of
studies of condom effectiveness and the prevention of STIs.
References
- U.S. National Institute of Allergy and Infectious Diseases (NIAID).
Scientific Evidence on Condom Effectiveness for Sexually
Transmitted Disease (STD) Prevention [workshop summary], NIAID,
Herndon, VA, June 12-13, 2000. Available online;
Cates W Jr. The NIH condom report: the glass is 90% full. Fam
Plann Perspect 2001;33(5):231-33; U.S. Centers for Disease
Control and Prevention. Fact Sheet for Public Health Personnel:
Male Latex Condoms and Sexually Transmitted Diseases. Available online.
- Coburn T. CDC's deadly "safe sex" program and
suppression of landmark condom report [news conference press
release], Washington, DC, July 24, 2001.
- Steiner MJ, Cates W Jr, Warner L. The real problem with male
condoms is nonuse. Sex Transm Dis 1999;26(8):459-62.
- Weller S, Davis K. Condom effectiveness in reducing heterosexual
HIV transmission (Cochrane Review). In The Cochrane Library,
Issue 1. Oxford, UK: Update Software, 2002; Mann J, Stine C,
Vessey J. The role of disease-specific infectivity and number of
disease exposures on long-term effectiveness of the latex condom. Sex
Transm Dis 2002;29(6):344-49.
- Trussell J, Kowal D. The essentials of contraception. In Hatcher
RA, Trussell J, Stewart F, et al., eds. Contraceptive Technology,
Seventeenth Revised Edition. (New York: Ardent Media, Inc.,
1998)216.
- Steiner.
- Cates W Jr, Hinman AR. AIDS and absolutism — the demand for
perfection in prevention. N Engl J Med 1992;327(7):492-94.
- Garnett GP, Anderson RM. Strategies for limiting the spread of HIV
in developing countries: conclusions based on studies of the
transmission dynamics of the virus. J Acquir Immune Defic Syndr
Hum Retrovirol 1995;9(5):500-13.
- Adams MB. Effect of condoms on reducing genital herpes
transmission. JAMA 2001;286(17):2095.
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