stretches from Uganda and Kenya southward to include Rwanda, Burundi, Tanzania, Malawi, Zambia, Zimbabwe, and Botswana.
Patients seeking treatment today probably contracted the virus years ago. Thus, no matter how serious the situation currently appears, there will be very large increases in the number of AIDS deaths in sub-Saharan Africa in the future. By the year 2010, demographers project that life expectancy will fall from 66 to 33 years in Zambia, from 70 to 40 years in Zimbabwe, from 68 to 40 years in Kenya, and from 59 to 31 years in Uganda.
There is encouraging evidence that intervention programs to change behavior can be effective in preventing the spread of HIV. Public awareness of the AIDS epidemic is extremely high throughout Africa, and condom sales have risen dramatically across the continent in the past few years. Other promising findings include a recent reduction in the prevalence of HIV-1 infection among young males in rural Uganda and evidence that treating sexually transmitted diseases (STDs) in rural Tanzania may reduce the spread of HIV. But many interventions have been experimental and small scale and so are not sufficient to reverse the course of the epidemic. At the same time, discovery of an effective vaccine or treatment shows little promise. Furthermore, even if a vaccine or cure were developed, it would probably not be sufficient to bring a speedy end to the epidemic—because of imperfect effectiveness, cost, and less than universal distribution and acceptance. In addition, many of the millions of people already infected with HIV are unaware of their status and so represent a pool capable of passing the virus to new cohorts. Thus, changing human behavior to slow the speed or limit the extent of transmission will remain for the foreseeable future the first and probably the most important line of defense against HIV/AIDS in sub-Saharan Africa. More and better social and behavioral research is needed to develop more effective and acceptable preventive strategies and to find more effective ways of mitigating the negative effects of the epidemic.
Perhaps the most important argument for immediate action to slow the further spread of HIV is that, as suggested above, in many parts of the region the epidemic has not yet peaked. HIV tends to spread quickly among individuals whose behaviors place them at high risk of infection, such as commercial sex workers and their clients; it spreads thereafter—at first slowly and then at an accelerated pace—into the general population. In many sub-Saharan African countries the disease has already spread widely, but in others it has not. Because the cost-effectiveness of prevention efforts declines rapidly as the epidemic spreads, the timing of interventions is crucial. Failure to control the epidemic now will mean that far more costly and difficult interventions will be necessary in the future.
Another important reason for acting now to revitalize programs to combat