An integrated system for the control of the major human helminth parasites.

Disease due to virtually all of the human helminth parasites can be prevented simultaneously by a simple system based on the following premises: 1) helminths do not multiply within their definitive hosts, and their distribution in host populations is overdispersed; 2) disease manifestations occur largely in the small proportion of hosts, often school children, with heavy worm burdens; and 3) a few single-dose, broad-spectrum anthelmintics given in low doses at prolonged intervals can maintain worm burdens below pathogenic levels for almost all of the major human helminth parasites. The three drugs might be albendazole or one of the other benzimidazoles for hookworm, ascaris and trichuris; ivermectin for the filaria, including onchocerca and many other nematodes such as strongyloides; and praziquantel for virtually all trematodes and cestodes. The target group would be school children treated at intervals set to maintain worm burdens below the disease-inducing threshold. It is possible that all three drugs could be administered in low doses simultaneously at yearly intervals. Studies will be necessary to examine drug interactions, development of drug resistance, optimal dosages and timing, and effects on morbidity.