Calverton, MD - HIV tests among thousands of men and women provide a sobering look at the international epidemic. A new publication, HIV Prevalence Estimates from the Demographic and Health Surveys [English version] [French version], summarizes the results of population-based HIV tests in 28 countries among more than 400,000 men and women worldwide.
Starting in 2001, the MEASURE DHS project included blood tests for HIV in its national surveys, leading world experts to readjust international estimates of HIV prevalence. While this readjustment lowered the estimates of HIV infection worldwide, the new report describes the international burden of the epidemic with prevalence rates ranging from less than one percent in Asia and West Africa to almost 26 percent in Swaziland. Southern Africa is by far the most affected region. About one in four adults is infected in Lesotho and Swaziland and 18 percent in Zimbabwe. Less than one percent of the population is infected in the three Asian countries with DHS-based HIV estimates-India, Cambodia, and Vietnam. In India, however, less than one percent means that close to 2 million people age 15-49 are infected with HIV.
HIV Affects All Ages
In most African countries women start having sexual intercourse younger than men, increasing their risk of contracting HIV earlier in life. In almost all countries HIV prevalence among women peaks between 25-34. Almost 50 percent of Swazi women between ages 25-29 are infected with HIV and about 35 percent of Zimbabwean women age 30-34. Among men, however, infection rates peak at ages 35-39. In Swaziland where the DHS tested older adults, 28 percent of men age 50-54 are HIV positive, as are 17 percent of men age 55-59 and 13 percent age 60 and older.
The DHS findings show that HIV continues to be an urban epidemic. City dwellers are more likely to be infected in all but two of the 28 countries-the Dominican Republic and Senegal. In some countries the urban-rural difference is striking. In the Central Africa Republic, for example, 8 percent of urban residents are infected compared to 5 percent of rural residents.
When the HIV status between marital partners is different prevention is more complex. According to DHS findings in Africa, discordant couples, that is, one partner is positive and the other is negative, range from 1 percent in Niger and Mali to 14.3 percent of couples in Lesotho and 16.4 percent in Swaziland.
DHS household surveys typically interview nationally representative samples of over 10,000 men and women age 15-49. Along with the verbal interview, the survey can include blood tests for anemia, malaria, HIV, and other conditions.
MEASURE DHS is implemented by Macro International and funded by the United States Agency for International Development (USAID) and the President's Emergency Plan for AIDS Relief (PEPFAR).