In the early 1980's, the medical community first noticed AIDS among gay men in the United States. By the mid-1980's, it was predicted that AIDS would eventually spread quickly among heterosexuals in the industrialized world. This has not happened. In sub-Saharan Africa, AIDS has spread quickly, primarily through heterosexual contact. Why the difference? In sexual acts, the penetrator can easily give HIV to the penetrated, if no condom is used. In the industrialised world, it is easy for a man to give HIV to a woman, but difficult for a woman to give it to a man. In sub-Saharan Africa, many men have untreated sexually transmitted diseases that cause open sores on their private parts. As a result, it is easy for a woman to give HIV to a man. So whereas in the industrialised world, a man gives HIV to a woman and then the virus typically stops; in sub-Saharan Africa, the virus bounces back and forth between genders like a pinball.

In addition, sub-Saharan Africans do not fear death in the same way as people in the industrialised world. Death is common and always near. So people worry less about a disease with a long incubation period when in countries where the average life expectancy is around 38 years. This is one of the reasons that condoms are less commonly used there.

On the brighter side, the fatalism of people in sub-Saharan Africa is connected to the joy in their lives. They spend more time with their families and friends, more time singing, dancing and laughing than people in the industrialised world.

In most of southern Africa, about one in three adults has HIV in urban areas and one in seven in rural areas. The reason the HIV rate is higher in urban areas is that men are wealthier. It is common for a man to promise to help support a woman if she will have sex with him - the deal usually does not involve a condom since sex without a condom feels better for a man. The low status of women, combined with their poverty, often gives such women little choice in the matter.

The increase in tuberculosis in sub-Saharan Africa is directly connected with AIDS. People with HIV/AIDS have impaired immune systems that both make catching tuberculosis easier and getting rid of it, even with treatment, difficult. In addition, the treatment is often of poor quality, a symptom of the poverty of the medical system.