School children in Africa can be treated for intestinal worms and schistosomes - the parasites that cause bilharzia - in association with school feeding programmes for as little as 20 US cents per year, an expert from the World Health Organisation (WHO) said on Wednesday. Bilharzia is transmitted by parasites present in snails that live in still fresh water and is a major problem for communities that live near lakes and dams. The WHO reckons it is directly responsible for the death of 200,000 people per year in Africa alone.