Community-directed treatment of onchocerciasis with ivermectin in Takum, Nigeria.

A study to identify factors within the community that can ensure sustainable community-directed treatment (ComDT) with ivermectin compared the effectiveness of programme-designed (PD) and community-designed (CD) strategies in 37 villages in the Takum area of Nigeria. In a subset of PD villages, designated PD1, communities were asked to use the village heads as community-directed distributors (CDD), and the other communities (PD2) were asked to select female distributors, and both were instructed to use the house-to-house method of distribution. Community-designed communities, on the other hand, were asked to design their own approach. All study communities received health education, treatment guidelines, and training enabling them to determine appropriate dosage. A total of 1744 people were interviewed about their experiences after two treatment cycles. Communities preferred honest, reliable community members as CDDs, but few women were selected. The results show striking similarity between PD and CD villages in many respects. In the PD1 villages, where the programme designated the village head as CDD, the mode of distribution was changed from house-to-house to central point, and distribution took place in the compound of the village head. In the PD2 villages, where the programme specified distributors should be women, the women who were selected were replaced by their male children. These changes to the original design were consistent with the local cultural norms and made the arrangement for distribution more acceptable to the people. Programme-designed villages that used the village head as distributors performed better than those that used women, and the coverage in the former group compares well with that of CD villages. Only five villages achieved coverage > 60%, but dosage was correct in most cases (87.4%). Drug shortage was the most frequent reason for non-treatment. Communities devised means for ensuring equity and fairness in sharing their limited supply and freely altered the original designs to fit local norms and values. These changes to the original design were consistent with local norms and were acceptable to the people. The success of this strategy should be tested in other parts of Nigeria. Long-term success of ComDT, however, requires a reliable drug supply and inputs from professionals in the health system for minimal supervision. The core issues that determine sustainability of ComDT appear to be not so much in the structure, but in the process by which they are introduced. Communities will only sustain a programme where the process of implementation fits well with local norms and where communities are free to alter PD procedures that are inconsistent with local customs.

Call to consolidate achievements for onchocerciasis and lymphatic filariasis control.

The Bernhard Nocht Institute for Tropical Medicine and the UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases held an international conference to review recent achievements in research and control of onchocerciasis and lymphatic filariasis on 19-23 September 2001 in Hamburg, Germany.

Irreversible effects of ivermectin on adult parasites in onchocerciasis patients in the Onchocerciasis Control Programme in West Africa.

Ivermectin is an effective drug for the treatment of human onchocerciasis, a disease caused by the parasitic filarial nematode Onchocerca volvulus. When humans are treated, the microfilariae normally found in the skin are rapidly and very nearly completely eliminated. Nonetheless, after a delay, microfilariae gradually reappear in the skin. This study is concerned with the causes of this delay. Hypotheses are tested by comparing the results of model calculations with skin microfilaria counts collected from 114 patients during a trial of five annual treatments in the focus area of Asubende, Ghana. The results obtained strongly suggest that annual treatment with ivermectin causes an irreversible decline in microfilariae production of approximately 30%/treatment. This result has important implications for public health strategies designed to eliminate onchocerciasis as a significant health hazard.