A new technique for the determination of microfilarial densities in onchocerciasis.

Precise measurement of the parasite load in helminthic infections makes it possible to correlate morbidity, the individual response to treatment, and the best control methods. A membrane filtration technique was recently developed for quantifying Wuchereria bancrofti microfilaraemia. The present paper describes its application to onchocerciasis in a study on 107 patients in northern Togo. The technique is cheap and simple to apply under field conditions, and is extremely efficient at recovering microfilariae from skin snips.