Gambia

Ebrahim M. Samba

1992 Balzan Prize for Preventive Medicine

For his leadership in the fight against Onchocerciasis (River Blindness) in West Africa. Through the World Health Organization’s Onchocerciasis Control Programme, which he directed, hundreds of thousands of humans have been protected against the disease and so prevented from becoming blind. Due to its success, this programme has made the repopulation of large fertile areas of land possible, thus having a decisive impact on the socio-economic situation of the participating countries.

Dr. Ebrahim M. Samba (1932 – 2016) has been the Director of the “Onchocerciasis Control Programme” (OCP) of the WHO in West Africa since 1980. The Programme was started in 1974 with the enthusiastic support of E. M. Samba who at that time was a representative of his country, Gambia, at the WHO.
Onchocerciasis (also known as River Blindness) is caused by a filarial worm (Onchocerca volvulus). It is transmitted through bites of a blood-sucking blackfly (Simulium damnosum), whose larvae develop in well-aerated, fast-flowing rivers. In humans who have been infected by blackflies the sexually mature worms develop and accumulate mainly in skin nodules.
These macrofilariae are ovoviviparous; they do not lay their eggs, but produce live microfilariae of microscopical size, which migrate in the skin. Under conditions not yet fully understood, they may penetrate the eyes and cause severe damage. They also represent the stage which must be taken up by blackflies again, thus completing the life cycle of the worm.
Onchocerciasis leads to a heavily disabling illness which is often accompanied by blindness. Millions of West Africans have suffered from this disease. It also led to enormous social and economic consequences by inducing populations to abandon large fertile regions.
Valuable and leading endeavours in combating this disease were made by French and British workers in the fifties and sixties. The major feature of Samba and his co-workers was to effectively apply existing scientific knowledge to a Public Health Programme and to further develop it. This Programme enabled hundreds of thousands of humans to be protected against a most disabling disease. The successful control of the blackfly with various insecticides has indeed stopped transmission of the disease in almost all the initial OCP area. In the extension areas, where the fight against the blackfly is still at an early stage, the advent of a drug, which eliminates large numbers of microfilariae and is suitable for mass treatment, rendered it possible to alleviate the suffering of the people infected, and to prevent them from turning blind. Also, the development of a promising macrofilaricide has been taken up.
In particular, Samba and his group made the following contributions:
– they have successfully extended the Programme area by some 50%, thus countering reinvasion of blackflies from distant breeding sites;
– they have carefully tested the effect of the microfilaricide Mectizan when applied un a very large scale;
– they actively participated in the development of a macrofilaricide (Amocarzin);
– they have made significant progress towards setting up an immuno-diagnostic test suitable for application in the field;
– they greatly contributed to an evolution of the Public Health policy of the eleven Participating countries, being now prepared to integrate anti-Onchocerciasis activities into the existing Basic Health Services.
Dr. Ebrahim M. Samba has not only proved to be an excellent leader of this team, but is also highly respected by national officials and local populations alike.