The puzzle of Africa's HIV and AIDS rates.

The puzzle of Africa's HIV and AIDS rates.

The puzzle of Africa's HIV and AIDS rates.

Health and medicine explained.
May 15 2007 3:00 PM

Sex Nets

The puzzling rise and fall and rise of HIV and AIDS in Africa.

The Invisible Cure by Helen Epstein.

In 10 countries in sub-Saharan Africa, HIV has infected 10 percent or more of adults. No other region of the world has a country with a prevalence rate in the double digits; in North America and Europe, HIV infection has never even reached 1 percent—anywhere. To tease out the reasons for the difference, epidemiologists have journeyed deep into one of sub-Saharan Africa's thickest and dankest jungles: human sexual behavior. AIDS researchers over the past two decades have dissected when Africans start having sex, how many partners they have, how frequently they do it, their marital status and condom use, whether sex involves the exchange of money or a gift, the ability to refuse, exotic ritual practices, and orifice preferences. Uganda has received particularly close scrutiny, and is at the hub of Helen Epstein's new book, The Invisible Cure: AIDS in Africa.

As Epstein recounts, Uganda had one of the world's most intense AIDS epidemics, peaking in 1991 at an adult prevalence rate of 15 percent, though this has since dropped by more than half. Many trees have died for documents that conclude that "we may never fully know" what accounts for this "miracle" and why it has happened in only a few other countries. Epstein sides with the camp that attributes Uganda's HIV/AIDS drop to behavior change. This was catalyzed by an "extraordinarily pragmatic and candid" response to the epidemic at all levels of society—in contrast to many other devastated countries, where health officials misunderstood how HIV was spreading. The main driver of severe HIV/AIDS epidemics is the distinct way that populations form sexual networks, Epstein argues. And on this topic, she hits many high notes. Ultimately, however, Invisible Cure makes a more convincing case for the cause of double-digit HIV/AIDS epidemics than for their cure.


Epstein, a lapsed laboratory scientist who did graduate work in public health, is a plucky and enterprising character. She abandoned her molecular studies of insects for a self-designed (though ill-fated) AIDS vaccine research project in Uganda and then visited half a dozen sub-Saharan countries over the next decade as a consultant for the Ford Foundation and Human Rights Watch and as a journalist. Her time in Africa convinced her that home-grown social movements powerfully can lead to partner reduction and curb HIV's spread.  Forget "tired stereotypes" about how Africans are more promiscuous and have more premarital sex, or indulge in bizarre customs like "widow cleansing" and "dry sex." Epstein authoritatively cites research that debunks these as the explanations for high rates of HIV/AIDS. She also persuasively questions the once-popular biological argument that pointed to the circulation in Africa of more infectious HIV subtypes. Instead, as Epstein explains, scientists who model the spread of HIV showed as long ago as 1993 the dangers of what they call "concurrency networks."

In many sub-Saharan African locales, both men and women have long-term sexual relationships with a few people at a time. This concurrent partnering contrasts with the serial monogamy that is common in, say, the United States, where people typically move from relationship to relationship or have brief affairs. One provocative study that Epstein cites compared an imaginary population that practiced concurrent partnering with one that was serially monogamous. Each population had the same number of partners over five years. HIV spread 10 times faster in the concurrency network.

"If the network of concurrent relationship serves as a superhighway for HIV, partner reduction would be like a sledgehammer, breaking up the highway into smaller networks," Epstein writes. She celebrates the well-publicized "Love Carefully"/"Zero Grazing" campaigns in Uganda. These vague slogans did not encourage abstinence but instead implicitly recognized concurrent relationships as a cultural norm and encouraged men in particular to avoid "short-term casual encounters." Epstein also praises community-based AIDS groups in Kagera, Tanzania, for similarly encouraging frank talk about the disease and spreading the word that casual sex carries great risks. Epstein repeatedly laments that these approaches have received scant attention.

Reducing the number of partners plainly makes sense as an HIV prevention strategy. However, it's only one of many variables in a maddeningly complex equation. I finished the book with only the fuzziest idea of how the Ugandan and Tanzanian campaigns relate to the mathematical modeling that compared concurrency with serial monogamy. These populations were still practicing concurrency, albeit concurrency lite.

The bad guys in Epstein's narrative are the misguided, moneyed donors and public-health officials who try to impose their agendas—condom promotion, abstinence, treating other sexually transmitted diseases, microloans—without paying close enough attention to local realities. "As a result, the programs they introduced were largely ineffective and may have inadvertently reinforced the stigma, shame and prejudice surrounding the disease," she writes, ruing their trampling of smaller, more effective projects. Epstein also chides South Africa President Thabo Mbeki for flirting with AIDS denialists, Ugandan President Yoweri Museveni for flirting with George W. Bush's Christian Right agenda, and Swaziland's polygamous King Mswati III for flirting with young Swazi women. As one of my friends says about Vernor's Ginger Ale, it's a busy drink. At times, Invisible Cure ends up reading like a collection of feature stories about AIDS in Africa—several of them told earlier in depth by others, as in Mark Schoof's 1999 Pulitzer Prize-winning Village Voice series.