From the UN Report on the Global AIDS Epidemic, 2004


Sub-Saharan Africa has just over 10% of the world’s population, but is home to close to two-thirds of all people living with HIV—some 25 million (range: 23.1–27.9 million). In 2003 alone, an estimated 3 million people (range: 2.6–3.7 million) in the region became newly infected, while 2.2 million (range: 2.0–2.5 million) died of AIDS. Among young people 15–24 years of age, 6.9% of women (range: 6.3–8.3%) and 2.1% of men (range: 1.9–2.5%) were living with HIV by the end of 2003.



Many African countries are experiencing generalized epidemics. This means that HIV is spreading throughout the general population, rather than being confined to populations at higher risk, such as sex workers and their clients, men who have sex with men, and injecting drug users. In sub-Saharan Africa, as the total adult population is growing, the number of people living with HIV is increasing, with the result that adult prevalence has remained stable in recent years (see Figure 5). However, this overall stabilization of prevalence in the sub-Saharan region conceals important regional variations.

Although prevalence is stable in most countries, it is still rising in a few countries, such as Madagascar and Swaziland, and is declining nationwide in Uganda and in smaller areas in several other countries. Stabilized infection levels in an epidemic often result from rising death rates from AIDS, which conceal a continuing high rate of new infections. Even when HIV prevalence falls, as in Uganda, the number of new infections can remain high.



Within countries, there can be variations in prevalence by region. It has long been recognized that in most countries HIV infection levels are higher in urban than in rural areas. A review of national community-based studies shows that HIV prevalence in urban areas is about twice as high as in rural areas (see Figure 6).

Women face greater risk
African women are being infected at an earlier age than men, and the gap in HIV prevalence between them continues to grow. At the beginning of the epidemic in sub-Saharan Africa, women living with HIV were vastly outnumbered by men. But today there are, on average, 13 infected women for every 10 infected men—up from 12 infected women for every 10 infected men in 2002. The difference between infection levels is more pronounced in urban areas, with 14 women for every 10 men, than in rural areas, where 12 women are infected for every 10 men (Stover, 2004).

The difference in infection levels between women and men is even more pronounced among young people aged 15–24. A review of HIV-infection levels among 15–24-year-olds compared the ratio of young women living with HIV to young men living with HIV (see Figure 7). This ranges from 20 women for every 10 men in South Africa, to 45 women for every 10 men in Kenya and Mali.



In sub-Saharan Africa, heterosexual transmission is by far the predominant mode of HIV transmission. Unsafe injections in health-care settings are believed to be responsible for around 2.5% of all infections. Recently, it has been suggested that unsafe medical injections account for most HIV transmission in the region (Gisselquist et al., 2002). However, a recent thorough review of the evidence concluded that, while a serious issue, unsafe injections are not common enough to play a dominant role in HIV transmission in sub-Saharan Africa (Schmid et al., 2004).

The ‘unsafe injections’ theory does not take into account the possibility that people sick with HIV-related disease might receive more injections. Moreover, the pattern of injections in health-care settings does not match sub-Saharan Africa’s HIV-infection distribution pattern by age and sex. Although the safety of injections must be assured in all health-care settings, effective strategies addressing sexual transmission have the largest potential to turn the epidemic around in this region.

Diverse levels and trends
There is tremendous diversity across the subcontinent in the levels and trends of HIV infection (see Figure 8). Southern Africa remains the worst-affected region in the world, with data from selected antenatal clinics in urban areas in 2002 showing HIV prevalence of over 25%, following a rapid increase from just 5% in 1990. Prevalence among pregnant women in urban areas was 13% in Eastern Africa in 2002, down from around 20% in the early 1990s. During this period, prevalence in West and Central Africa remained stable.

There is no single explanation for why the epidemic is so rampant in Southern Africa. A combination of factors, often working in concert, seems to be responsible. These factors include poverty and social instability that result in family disruption, high levels of other sexually transmitted infections, the low status of women, sexual violence, and ineffective leadership during critical periods in the spread of HIV. An important factor, too, is high mobility, which is largely linked to migratory labour systems.



The epidemics in Southern Africa have grown rapidly. For example, in Swaziland, the average prevalence among pregnant women was 39% in 2002—up from 34% in 2000 and only 4% in 1992. Moreover, in a number of countries, the penetration of the virus into the general population has exceeded what was considered possible. In Botswana, weighted antenatal clinic prevalence has been sustained at 36% in 2001, 35% in 2002, and 37% in 2003. In South Africa, prevalence among pregnant women was 25% in 2001 and 26.5% in 2002.

In parts of East and Central Africa, there are signs of real decline in infections in some countries. This is most notable in Uganda, where national prevalence dropped to 4.1% (range: 2.8–6.6%) in 2003. In Kampala, prevalence was around 8% in 2002—down from 29% 10 years ago. But even Uganda cannot afford to relax: surveys suggest that today’s young people may be less knowledgeable about AIDS than their counterparts in the 1990s.