HIV / AIDS IN AFRICA UPDATE - 2001

 Sub-Saharan Africa is the region most affected by the HIV/AIDS pandemic.  

• AIDS is now the leading cause of death in Africa.
• 25.3 million people are now living with HIV/AIDS
• 70% of all HIV/AIDS sufferers in the world are African.
• 2.4 million people died of AIDS in 2000.
• There are now an estimated 5 million AIDS orphans
• AIDS has led to a marked decrease in life expectancy in many countries.
• HIV/AIDS is taking an increasing toll on the younger population, as the older population dies off.
• There are signs that HIV incidence may have stabilized in Sub-Saharan Africa.

The Current Situation.

For the first time there is evidence that the incidence of HIV in Africa may be stabilizing. 70% of all worlds HIV/AIDS sufferers are African, yet only a tenth of the world's population lives in Africa south of the Sahara. The numbers affected by the epidemic is overwhelming, already more than 15 million people have died, a quarter of them children. AIDS was responsible for over an estimated 2 million African deaths in 2000. More Africans are living with HIV than ever before: 25.3 million. Eight African countries have HIV incidences of over 15% in the adult population and another eight have levels of between 10 and 15%.

No country has escaped the virus, but some are far more severely affected than others. Southern Africa holds the most of the world’s hard-hit countries, and is now the region where the bulk of new infections are seen. South Africa has one of the fastest growing epidemics in the world; HIV incidence increased from 12.9% in 1997 to 19.9% in two years. South Africa has the highest number of people living with HIV/AIDS (PHAs) – 4.2 million. 

Botswana, South Africa’s neighbor, with well over a third of adults (35.8%) infected with HIV has the highest incidence rates in the world. Other countries in Southern Africa also have very high rates; in Namibia, Swaziland and Zimbabwe, Lesotho current estimates show that between 20% and 25% of people aged 15–49 are living with HIV or AIDS.

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Table showing the countries in Africa with the highest levels of HIV

Country	1999	1999	Fig.1 Map of estimated percentage of adults (15-49yrs) infected with HIV at end 1999
Botswana Swaziland Zimbabwe Lesotho Zambia South Africa Namibia Malawi Kenya Central African Republic Mozambique Djibouti Burundi Rwanda Cote d’Ivoire Ethiopia Uganda Cameroon Burkina Faso Nigeria	36% 25% 25% 24% 20% 20% 20% 16% 14% 14% 13% 12% 11% 11% 11% 11% 8% 8% 6% 5%	25% 19% 26% 8% 19% 13% 20% 15% 12% 11% 14% 10% 8% 13% 10% 9% 10% 5% 7% 4%

The figures are the based on estimates in reports published by UNAIDS at the end of 1999, and 1997. They include all people with HIV infection, whether or not they have developed symptoms of AIDS, alive at the end of 1999. The figures are estimates based on a number of different sources of information, rather then exact counts of infections.

Eastern African countries are also severely affected. In Zambia, more than one in four people living in the cities are HIV positive. Over one in ten adults are infected with HIV in Burundi, Central African Republic, Djibouti, Ethiopia, Kenya and Rwanda.

West Africa has generally been less affected than Southern or East Africa, and HIV rates have remained low and relatively stable. Only Cote d’Ivoire (11%) has HIV incidence rates matching those in other parts of Africa.

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Status and trends of the HIV/AIDS epidemics in Africa

Spread of the virus

The HIV virus spread silently and stealthily through populations for years before the first AIDS cases were seen. It is only now, two decades after the virus first started spreading, that the repercussions of AIDS are being fully felt. The rate of HIV infection still continues to rise and has been characterized by epidemics that evolve with changing speed in different areas.

The different epidemic patterns are:

• The “silent emerging phase” seen in North Africa and Indian Ocean island countries where the incidence of HIV remains below one per thousand. In these countries the prevalent modes of transmission are similar to those seen in Western Europe. These countries have large numbers of sexually transmitted diseases, giving a potential for future increase in HIV incidence.
  
  
• Mature phase – seen in countries such as Uganda, Kenya and Tanzania in East Africa, Zambia and Zimbabwe in Southern Africa, the epidemic became severe. In these countries HIV transmission is mainly through heterosexual sex, with infection in the teenage years and peaking before age 25. The rate of HIV incidence is typically over 10%.

• Intermediate phase – this is seen in many countries on the continent where HIV incidence is between 1-10%. The spread of HIV is similar to that seen in countries with mature epidemics.

• Explosive phase – under certain circumstances the epidemic may suddenly explode with rates of infection increasing rapidly in a very short time. In is not yet understood what causes this. South Africa, where the HIV incidence went from 12.9% to 19.9% in two years and Botswana, where the infection levels rose from 10% in 1992 to over 30% now, are examples of this trend.

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In a few countries in Africa, particularly those in West Africa HIV rates have remained low and relatively stable over a number of years. The reasons for the relative stability are not known, in some cases it could be due to early and sustained prevention efforts such as those seen in Senegal (1.8%). But elsewhere where, far less has been done to encourage safer sex it is not clear why this should be the case.

In many of these countries the low levels and slow growth of HIV have been attributed to social and cultural factors, but it may just be due to a delay in the establishment of the virus. Generally once the virus has found its way into a population and gained a foothold, it spreads rapidly. In Nigeria, the most populous country in Africa, which had been spared to an extent, HIV incidence increased from 4.1% in 1997 to 5.1% in 1999. This is a small but worrying increase, which may indicate that some parts of West Africa are just lagging behind the rest of Africa with the severity of their epidemics.

It is now known that once HIV has entered a community, it spreads silently until there is a sudden explosive growth in new infections. The rate of increase will reach a peak and then gradually fall off as saturation is reached. This is when most of the people who are at greatest risk become infected, generally the older population. The infection rate then stabilizes at lower levels as people continue to be exposed to HIV. At the same time as the younger age groups reaching sexual maturity, become exposed to HIV and the infection becomes increasingly concentrated in young people.

Stabilization of the epidemic can also occur naturally as a result of the dynamic balance between deaths and new infections. High death rates from HIV/AIDS, as has been observed in many African countries removes infected people from the population, thereby leading to an apparent fall in the prevalence of HIV. This may have the effect of masking underlying high incidence of HIV in younger populations. Age specific sampling can reveal such an effect.