AIDS Prevention in Generalized Epidemics: What Works?

House Committee on Foreign Affairs

September 25, 2007

Norman Hearst, MD MPH

Professor of Family Medicine and Epidemiology

University of California, San Francisco

We’re here today to talk about making PEPFAR sustainable, and the key to sustainability must be prevention. We cannot treat our way out of this epidemic. Even now, five people are being infected with HIV in Africa for every one starting treatment. And treatment or not, these people will die of AIDS.

For prevention, it’s fundamental to distinguish between “concentrated” and “generalized” HIV epidemics. These are different situations that require very different strategies. In most countries, HIV is mainly transmitted in high risk settings and groups, including men who have sex with men, injecting drug users, and commercial sex, so that’s where you need to do prevention.

But in generalized epidemics, transmission is widespread in the heterosexual population, so you can’t focus only on high risk groups. Just a few countries in Eastern and Southern Africa have this pattern. But these countries, because of their very high infection rates, account for most of the world’s HIV infections. Most PEPFAR priority countries have generalized epidemics.

Five years ago, I was commissioned by UNAIDS to conduct a technical review of how well condoms have worked for AIDS prevention in the developing world. My associates and I collected mountains of data, and here’s what we found.

First, condoms are 85-90% effective for preventing HIV transmission when used consistently. We then looked at whether condom promotion has been successful as a public health strategy – something very different from individual effectiveness. Here we found good evidence for effectiveness in concentrated epidemics. For example, condoms made an important contribution to controlling HIV among gay men in places like San Francisco and epidemics driven by commercial sex in places like Thailand.

We then looked for evidence of a public health impact for condoms in generalized epidemics. To our surprise, we couldn’t find any. No generalized HIV epidemic has ever been rolled back by a prevention strategy based primarily on condoms. Instead, the few successes in turning around generalized HIV epidemics, such as in Uganda, were achieved not through condoms but by getting people to change their sexual behavior.

UNAIDS did not publish the results of our review, but we did ourselves. I would like to have the following article entered into the record:

Hearst N, Chen S. Condoms for AIDS Prevention in the Developing World: Is It Working? Studies in Family Planning 2004;35:39-47.

These are not just our conclusions. A recent consensus statement in The Lancet was endorsed by 150 AIDS experts, including Nobel laureates, the president of Uganda, and officials of most international AIDS organizations. This statement endorses the ABC approach to AIDS prevention: Abstinence, Be faithful, and Condoms. It goes further. It says that in generalized epidemics, the priority for adults should be B (limiting one’s number of partners). The priority for young people should be A (not starting sexual activity too soon.) C (condoms) should be the main emphasis only in settings of concentrated transmission, like commercial sex. I also ask that this article be entered into the record:

Halperin DT, Steiner MJ, Cassell MM, Green EC, Hearst N, Kirby D, Gayle HD, Cates W. The time has come for common ground on preventing sexual transmission of HIV. Lancet 2004; 364: 1913-1915.

PEPFAR follows this ABC approach. Last year, I was on a team reviewing PEPFAR’s prevention activities in three African countries for the Office of the Global AIDS Coordinator. We found a strong portfolio of prevention activities that mixed A, B, and C (though, in my opinion, probably not enough B.) This contrasted with other funders that often officially endorse ABC but in practice continue to put their money into the same old strategies that have been so unsuccessful in Africa for the past 15 years: condoms, HIV testing, and treating other sexually transmitted infections.

One might ask why they continue to do this despite all the evidence. It’s difficult to convey the tremendous inertia for doing the same old things. First, they’re relatively easy to do. Second, many of the implementing organizations and individuals have backgrounds in family planning. They’re good at distributing condoms and providing clinical services but may have no idea how to get people to change sexual behavior. Third, decisions are often made by expatriates and westernized locals trained in rich countries who have internalized prevention models from concentrated epidemics. Finally, if you try to do everything, expensive clinical services quickly eat up budgets, leaving little for the critical A and B of ABC.

Let me close with a warning regarding talk about “ABC plus” or “moving beyond ABC” and diverting AIDS prevention funding to whatever other good cause people are promoting. Always ask, “Where is the evidence?” For example, I’m all in favor of poverty alleviation. But in most countries with generalized epidemics, the rich have higher HIV infection rates than the poor. Similarly, for gender equity, many of the African countries with the best records in this regard (like Botswana) have the highest rates of HIV infection. Anything that dilutes the focus of AIDS prevention in Africa from changing sexual behavior may do more harm than good.