A new focus of onchoceriasis in the Sudan.

A new focus of onchocerciasis is reported from Upper Atbara River area in the Sudan. This river is a known seasonal breeding place of Simulium damnosum. The area was sparsely populated in the past but now, following agricultural development, is inhibited mainly by immigrants from Northern Nigeria and Chad. Clinically the common features are skin changes of the legs, thighs buttocks, arms and trunk. Other features are corneal opacities and small often deeply placed subcutaneous nodules. Choroido-retinal degeneration, genital elephantiasis and hydrocoele, commonly associated with onchocerciasis in other parts of the Sudan, are absent.