Studies on the concentration of Onchocerca volvulus microfilariae in the skin in relation to the nodule

The concentration of microfilariae in the skin over and at distance sup to 10 cm from the onchocercal nodule was studied in eight patients with established onchocerciasis. In spite of wide variations in microfilarial counts from snips taken from the same patient no significant differences were found in respect of distance or direction from the nodule. It is concluded that microfilariae are uniformly distributed in the skin around and onchocercal nodule in established infections.