Preliminary observations on the distribution of ivermectin in Nigeria for control of river blindness.

A total of 118,925 individuals in four Nigerian states was treated for onchocerciasis between February and December, 1991, using centralized and house-to-house distribution of ivermectin. Pre-treatment prevalences of the disease ranged between 28% and 90%. Only 0.7% of those treated reported adverse reactions within three days of treatment: 230 individuals (0.19%) had headache, 210 (0.17%) general body pains, 150 (0.12%) pruritus, 120 (0.10%) oedema, 80 (0.06%) fever, 20 (0.02%) dizziness, 15 (0.01%) vomiting, 10 (0.01%) diarrhoea, and 25 individuals (0.02%) noticed that they passed intestinal worms. Treatment in the endemic communities continues. The results show that mass treatment of onchocerciasis with ivermectin is quite safe and the drug's acceptability increases its potential as the drug of choice for control of onchocerciasis in Nigeria.