A pocket of controlled malaria in a holoendemic region of West Africa

Abstract

Yekepa, a mining town in northern Liberia with 16,000 inhabitants including 1500 expatriates, was built entirely since 1960. Although situated in a holoendemic region with constant human movements in and out of the town, the mining company succeeded in controlling malaria in Yekepa. Control is maintained by regular residual insecticide sprayings with DDT, regular larviciding with fuel oil and fortnightly issue of amodiaquine chemoprophylactic to all workers. A malariometric survey showed that the spleen and parasite rates were 11 and 13%, respectively, in the controlled areas and 95 and 67%, respectively, in surrounding regions not subjected to control measures. The dominant malaria parasite in the area was Plasmodium falciparum. No adult vectors were found in the town. In the surrounding villages the average room density of adult vectors was 3.8 and the sporozoite rate in a village very close to the town was 9.2%. The dominant vector of the area was Anopheles gambiae with A. funestus also present.