Since the emergence of AIDS in the early 1980s, it has become a pandemic affecting every country in the world. By end of 1999, more than 33 million people worldwide, a number that exceeds the entire population of Canada, were living with HIV. Over 11-million people have died in Africa from AIDS since the first outbreak in the mid-1980's. The World Bank has called the proliferation of AIDS in the sub-Sahara the greatest threat to economic, social and human development.

During 1998, some 5.8 million persons became newly infected with the AIDS virus. There were an estimated 2.5 million AIDS deaths during 1998, and more than half a million of these occurred among children. Some 95 per cent of HIV-infected persons live in developing countries, which are those least able to cope with the medical, social and economic consequences of the disease. The 21 countries with the highest HIV prevalence in the world are all in Africa, and in at least 10 of them the rate exceeds 10 percent of the population.

How AIDS kills

The AIDS virus, known as HIV, is transmitted from person to person via intimate contact with body fluids. By far the commonest mode of spread is sexual. HIV is also spread among intravenous drug users who share needles with each other. Transfusion of infected blood or blood products transmits the virus, as may unsafe injections such as those performed in a village market by unqualified healers.

Newborn babies may also contract the virus from their mothers, either just before or during birth or in some instances during breast feeding. Once inside the body, HIV invades the T-lymphocytes, which are white cells in the blood and a component of the immune system.

This invasion and initial proliferation of the virus may cause a brief flu-like illness. Then the immune system temporarily suppresses the manifestations of the infection and the virus remains to all appearances dormant for a period that in adults may range from anything between one and 10 years or more. During this latent period the HIV-infected person is nevertheless able to transmit the virus to his or her sexual partners.

Eventually, after the latent period, the immune system is overwhelmed by the virus. HIV affects two major components of immunity: the T-lymphocytes, which are responsible for what is called cell-mediated immunity and which normally fight diseases like TB; and mucosal immunity, which acts at the level of the linings of the respiratory and gastro-intestinal tracts.

At this stage opportunistic infections occur and this is the beginning of the clinical syndrome known as AIDS. In Africa, the first sign of AIDS is often a persistent debilitating diarrhoea that eventually causes profound weight loss and gives the condition its common name among English speakers there - slim disease.

Other manifestations include rapidly progressive tuberculosis, widespread infection with the Candida fungus causing thrush, and aggressive disease due to opportunistic infections that include herpes simplex, Pneumocystis carinii (causing pneumonia), cryptosporidiosis (causing diarrhoea) and toxoplasmosis (causing encephalitis, which is diffuse infection within the brain). Any of these infections is sufficient to kill an immune-suppressed person such as an AIDS patient.

Preventing AIDS

The ways that HIV can be transmitted are well known and thus prevention should be simple. The difficulty, however, lies in convincing communities and individuals to apply the knowledge that is available.

An example - HIV/AIDS project in Malawi A tiny southern African country with a population of some 10 million, Malawi has one of the highest prevalence rates of HIV in Africa.

MSF teams know the country well, having worked there since 1987 when there was a large influx of refugees from Mozambique.

Then, in 1992, once the majority of the refugees had returned home, our project focus turned to the growing problem of HIV among Malawi's nationals. 

Managing the AIDS

pandemic In some countries of southern Africa, up to a quarter of young adults are estimated to infected with HIV. The human, social and economic consequences of a catastrophe of this magnitude are in a sense unmanageable. All that control programmes can hope to do for those that are already infected is to try to soften the impact. The over-riding priority is evidently to prevent transmission and thus try to protect coming generations.

Many of the prevention strategies therefore target young people, before they become sexually active. Internationally, AIDS control efforts are coordinated by a coalition of United Nations agencies called UNAIDS. This organisation has the role of gathering epidemiological data and advising the health authorities in developing countries on appropriate control strategies.

UNAIDS estimates that during 1998 some 5.8 million persons became newly infected with HIV. That represents one man, woman or child every five seconds. Each of these events must be considered a failure of the world's preventive efforts and this underlines the extreme urgency of promoting support of control strategies everywhere. MSF projects in more than 80 countries address HIV as part of integrated health care for populations in danger.

Moreover, MSF has specific AIDS control projects in Rwanda, Ethiopia, Kenya, Uganda, Malawi, Mozambique, Democratic Republic of Congo (former Zaire), Armenia, Russia, Brazil, Cuba, Guatemala, Honduras, Nicaragua, Peru, Burma, Cambodia, China, Khazakhstan, Kyrghizia, the Philippines, Thailand, Vietnam, and among MSF treatment for AIDS In developed countries AIDS patients have access to a range of specific antiviral drugs such as AZT that have been shown to prolong life and even postpone the transition from dormant HIV infection to full-blown AIDS.

These drugs are also given to pregnant HIV-positive women and have the effect of reducing the risk of peri-natal transmission to their babies. In developing countries, however, where 95 per cent of HIV-positive persons are living, these drugs are not generally available because of their extremely high cost. The treatment programmes that MSF teams offer to AIDS patients include only elements that are sustainable by the local health services.