Evaluation of invermectin distribution in Benin, Côte d'Ivoire, Ghana and Togo: estimation of coverage of treatment and operational aspects of the distribution system.

Invermectin distribution by the Onchocerciasis Control Programme (OCP) was assessed in Benin, Côte d'Ivoire, Ghana and Togo, in terms of the proportion of villages which had been treated and the proportion of villagers in each village treated in the last round who had actually received treatment. These proportions were evaluated both for treatment in the last round of ivermectin distribution and for treatment since the beginning of the drug's distribution in each country. During the last treatment round, 97 (74.6%) of the 130 selected villages investigated in the four countries had received ivermectin treatment, and 67.2% of the members of these 97 treated communities had taken ivermectin. In general, higher percentages of the members of treated villages in Côte d'Ivoire and Ghana had been treated [with mean (S.D.) percentage values of 72.0 (5.2) and 71.6 (4.6), respectively] than in those of Togo [61.8 (5.6)] or Benin [64.2 (4.6)]. Overall, 893 (26.1%) of those interviewed had never received treatment since the beginning of ivermectin distribution but 29.4% had received all the annual treatments. The main reason for non-treatment during the last treatment round was absence from village (54.5% of those not treated), followed by non-eligibility (i.e. pregnant women and young children; 12.2%), refusal to take treatment (2.6%), and shortage of drugs (1.9%). Community approval for the programme was demonstrated when all treated individuals, including those who were absent at the last treatment round, said they would take the ivermectin during the next treatment. During the last treatment round, members of the community assisted in the distribution of the ivermectin tablets in 69 (71.1%) of the 97 treated villages which were investigated. Although only 26 (26.8%) of these 97 villages preferred community-based distribution of ivermectin to the 'mobile' method, it is believed that, with good education and efficient organization, the communities could be encouraged to undertake community distribution.