INLAND VALLEY SWAMP RICE DEVELOPMENT - MALARIA, SCHISTOSOMIASIS, ONCHOCERCIASIS IN SOUTH CENTRAL SIERRA-LEONE

The prevalence of malaria, schistosomiasis and onchocerciasis was dete rmined in 1,106 residents of five villages in the Moyamba District, So uthern Sierra Leone, to determine whether inland valley swamp (IVS) de velopment was associated with changes in the prevalence of malaria, sc histosomiasis and onchocerciasis in these villages. These parasitic di seases were studied in four villages receiving IVS, Food and Agricultu ral Organization (FAO) assistance and in one village not receiving FAO assistance. Malaria was the most prevalent infection, detected in 42. 6% of the persons examined, followed by O. volvulus (17.7%), S. haemat obium (0.6%) and S. mansoni (0.3%). Plasmodium falciparum accounted fo r 90.4% of the malaria infections, followed by P. malaria (2.1%), P. o vale (0.5%), and mixed infections (7.0%). The trend of infection to O. volvulus increased significantly with an increase in age. S. haematob ium (0.6%) and S. mansoni (0.3%) infections were low and no Biomphalar ia pfeifferi and Bulinus globosus were found in 33 IVS development swa mps examined. These data indicate that IVS development is associated w ith an increase in the prevalence of malaria infection, but not in the prevalence of O. volvulus, S. haematobium and S. mansoni.