Community treatment with ivermectin for onchocerciasis in the east Usambara mountains.

Ivermectin 150mcg/kg was given orally to 743 patients with positive skin snips for Onchocerca volvulus and to 697 residents in two villages in the Usambara mountains. 620 villagers attended for a second dose. On direct questioning, 98.7% patients with +ve skin snips and 91.8% villagers given mass chemotherapy admitted to adverse reactions. After a second dose, 16.6% had mild reactions. No serious problems were encountered. 167 of 170 repeat skin snips were negative. Repeated administration of ivermectin is well tolerated and offers a chance of reducing the burden of onchocerciasis in the Usambara mountains.