Rift Valley fever retinitis.

A 57-year-old Dutch woman, who had lived and worked in Tanzania for 26 years, developed serious, progressive bilateral retinitis after suffering from a fever of unknown origin. Fundus abnormalities in both eyes suggested that the woman had been infected with Rift Valley fever virus. Serologic studies confirmed this suspicion. White macular lesions accompanied to extensive vasculitis appear to be specific for Rift Valley fever retinitis.