Onchocerciasis--a potential revolution in its treatment.

Onchocerciasis is a major blinding disease affecting at least 28 million people in Africa and Latin America. Although a large-scale vector control program has been highly successful in limiting transmission of infection in West Africa, there has not been a satisfactory form of treatment available for those already infected or those living in other areas. Despite the fact that two drugs, diethylcarbamazine and suramin, are active against the filarial parasite that causes onchocerciasis, their use is severely limited by their toxicity and the reaction they induce. A newly developed drug, ivermectin, appears to offer a major revolution in the treatment of onchocerciasis. In a series of clinical trials, ivermectin has been shown to be an extremely effective microfilaricide which induces only minimal side effects. Ivermectin is given as a single oral dose which can be repeated on an annual basis. In view of its safety and efficacy and its ease of administration, it seems likely that ivermectin will be suitable for use in mass chemotherapy programs against onchocerciasis.