It's not a revealing discovery that sexual engagement with multiple partners increases the likelihood of getting some kind of an infection, HIV included. But this is increasingly getting attention as HIV/AIDS workers and researchers grapple with a ballooning epidemic in sub-Saharan Africa, where just 12 percent of men and 10 percent of women know their HIV status. More than anything else, it shows the lack of integration of HIV/AIDS and sexual reproductive health that is characteristic of many programs in Africa.

For example, over the past few years the term "small house" has gained currency in Zimbabwe, a country with 18 percent HIV prevalence rate among the 15 to 49 age group. Small house simply refers to the extra-marital affairs that married men or women have in secret.

"Small houses are a form of concurrent relationship in which a person is having regular sexual relations with another person, while at the same time continuing to have sex with their current primary sexual partner," says Lois Chingandu, Executive Director of Southern Africa HIV and AIDS Information Dissemination Service (SAfAIDS) in an ongoing electronic forum discussion on accelerating-prevention measures in Zimbabwe.

Usually, such relationships often include a powerful element of sexual-economic exchange. Because of women's subordinate economic status, they often enter into the relationships for financial gain, making themselves vulnerable to HIV infection. Also, in many African countries, cultural and traditional practices encourage multiple partnerships for men. Like in many societies around the world, men's sense of masculinity is often associated with sexual prowess.

"Researchers increasingly attribute the resilience of HIV in Botswana—and in southern Africa generally—to the high incidence of multiple sexual relationships," reports The Washington Post. "Europeans and Americans often have more partners over their lives, studies show, but sub-Saharan Africans average more at the same time."

While it's clearly a fallacy to say such partnerships are unique to sub-Saharan Africa, they do indeed facilitate the transmission of HIV because of other reasons.

"The fact is that concurrent sex or small houses are a key driver of the epidemic for a number of reasons: people do not know their status when they engage in sex; condom use is zero in these relationships, despite high HIV awareness levels; mutual fidelity is very rare; small houses are themselves driven by other drivers like power dynamics and gender inequality, which make it difficult for women on both sides of the relationship to demand protection, even when they know they are at risk," says Chingandu.

The World Health Organization (WHO) estimates that sub-Saharan Africa alone accounts for 65 percent of all new HIV infections. The primary transmission of HIV is through heterosexual contact.

The catch, however, is that most of the people who are infected, do not know that they are HIV-positive. Reducing the number of partners is key to HIV prevention, but must be promoted alongside the provision of other services—such as HIV testing, stigma reduction, access to treatment, and correct and consistent use of existing prevention methods.

In many parts of sub-Sahara Africa, HIV/AIDS lives in the shadow of silence, fear and death, and many people prefer not to know their status.

The UN estimates that nearly 80 percent of the people with HIV in poor and developing countries do not know they have it. In Africa alone, nearly 20 million people with HIV are not aware they have the virus.

The stigma associated with HIV/AIDS causes many people to shun HIV testing services.

And when people enter into a sexual relationship, they trust each other after a period of time to forgo protective measures, putting themselves at risk. The rate of the spread of the disease increases in the event of multiple concurrent sexual relationships.

Unfortunately, the AIDS response in Africa has largely steered away from matters of sex and sexuality. While there's a large amount of printed material on HIV and AIDS, it often ignores the heart of the matter: sex. NGOs, government and AIDS funders have concentrated efforts on alleviating the social manifestations of the disease. There's every justification to provide services to the affected populations, but equally important is the need to tackle often-taboo subjects associated with sex in wide-scale campaigns.

"Africans are overwhelmed with information on AIDS but not nearly enough that is useful," said The Washington Post's Craig Timberg, in a recent online chat with his readers.

If heterosexual contact is the main cause of the spread of the epidemic, it is imperative for African societies to start exploring the cultural, traditional, social, economic and political dynamics that define sexual behaviour, especially between men and women.

There's need to bring the sex back into HIV/AIDS work. Programs that promote safe sexual relations, even in multiple partnerships, need to be emphasized to harness the high rates of new infections.