Onchocerciasis in Malawi. 2. Subjective complaints and decreased weight in persons infected with Onchocerca volvulus in the Thyolo highlands.

In the course of an onchocerciasis survey in southern Malawi, body weight was recorded for 10,335 persons aged 20 years and older, and the body mass index was calculated for 5572. A history of symptomatic complaints was elicited from 5653 persons 20 years of age and older. Persons with microfilariae in the skin snips weighed significantly less than persons with negative skin snips. Symptomatic complaints of musculoskeletal pains, itching, dizziness and poor vision were reported more commonly in the group with microfilariae. These findings suggest that onchocerciasis should no longer be considered a disease affecting the eye and skin only but an infection which produces systemic effects as well. Systemic effects of onchocerciasis may lessen productivity of an endemic region by a process distinct from the effects of visual impairment.