The "ABC to Z" approach: condoms are one element in a comprehensive approach to HIV/STI prevention. (Introduction).

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-use (3)--not breakage or slip-page--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

(1.) 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: http://www.niaid.nih.gov/dmid/stds/condomreport.pdf; 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: http://www.cdc.gov/hiv/pubs/facts/condoms.pdf.

(2.) Coburn T. CDC's deadly "safe sex" program and suppression of landmark condom report [news conference press release], Washington, DC, July 24, 2001.

(3.) Steiner MJ, Cates W Jr, Warner L. The real problem with male condoms is nonuse. Sex Transm Dis 1999;26(8):459-62.

(4.) 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.

(5.) 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.

(6.) Steiner.

(7.) Cates W Jr, Hinman AR. AIDS and absolutism--the demand for perfection in prevention. N Engl J Med 1992;327(7):492-94.

(8.) 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.

(9.) Adams MB. Effect of condoms on reducing genital herpes transmission. JAMA 2001; 286(17):2095.