African Trypanosomiasis

The World Health Organization (WHO) described African Trypanosomiasis as below. To learn more about this disease and its prevention see their web site at : www.who.int/emc/diseases/tryp/trypanodis.html

African sleeping sickness is caused by trypanosomes which are protozoan parasites. It is transmitted to humans through the bite of the tsetse fly of the genus Glossina.

There are two forms, each caused by a different parasite :

	Trypanosoma brucei gambiense, which causes a chronic infection lasting years and affecting countries of western and central Africa;
	Trypanosoma brucei rhodesiense , which causes acute illness lasting several weeks in countries of eastern and southern Africa.

When a person becomes infected, the trypanosome multiples in the blood and lymph glands, crossing the blood-brain barrier to invade the central nervous system where it provokes major neurological disorders. Infection by trypanosomes causes neurological alterations which are often irreversible even after successful treatment. Psychomotor and neurological retardation even among cured children is frequent. Without treatment, the disease is invariably fatal.

Magnitude of the problem

Sleeping sickness is a daily threat to more than 60 million men, women and children in 36 countries of sub-Saharan Africa, 22 of which are among the least developed countries in the world. However, only 3 to 4 million of these people are under surveillance and the 45 000 cases reported in 1999 do not reflect the reality of the situation, but simply show the absence of case detection. The estimated number of people thought to have the disease is between 300 000 and 500 000.

Detection of people infected with sleeping sickness and subsequent patient care require well trained staff, resources, drugs and well-equipped health centres. Furthermore, without systematic screening of exposed populations and without treatment, the majority of sick people will die without ever having been diagnosed.

Economic and social impact

Sleeping sickness has a major impact on the development of rural areas by decreasing the labour force and hampering production and work capacity. It remains a major obstacle to the development of entire regions. In countries such as Angola, Democratic Republic of Congo or Sudan, the operational capacity to respond to the epidemic situation is largely surpassed and in certain endemic areas the observed prevalence is huge. In numerous provinces in these countries, a prevalence greater than 20% has been reported.