Never been to Sudan but I have been to Tanzania (and elsewhere in Africa). During my first visit (1981) we were on a drive from Arusha to Ngorongoro Crater. Driving along a dusty "road" with very little to see apart from semi-desert we happened upon a woman standing there selling corn with a young child at her side. The child had red/orange hair,a huge belly and little stick legs. I had never seen anything like it before. I only found out later that that's what a black child with chronic severe malnutrition looks like. I mention black because you'd expect such a child to have black hair.
It's an image that will stay with me until the day I die.