Integrated control of Onchocerca volvulus infection in a hyperendemic zone in Sierra Leone.

A simplified integrated method of onchocerciasis control involving mass chemotherapy with ivermectin, nodulectomy and health education was carried out in south central Sierra Leone. The prevalence of Onchocerca volvulus in the village community ranged from a low of 7.4% among the International School children to a high of 97.0% in Gbessebu. There was a significant (3-4%) overall reduction in the rate of infection after one year of ivermectin treatment (G = 2565.97, df = 11, P < 0.001). In addition, ivermectin treatment had a significant effect on the college community (G = 1168.21, df = 5, P < 0.001) and from year to year (G = 187.29, df = 1, P < 0.001), though the effect indicates the reduction varied between communities. Mass ivermectin treatment significantly (G = 1 3.79, df = 1, P < 0.005) reduced the rate of infection among school children, while the prevalence and intensity of infection was reduced by nodulectomy. Health education involving the community gave us an entry point and allowed us to gain the maximum cooperation and participation from the communities.