EARTH A New Wild | Clip | A Natural History Detective Story: Encountering a Snail
In Lake Malawi Bilharzia parasites grow and develop inside snails. The parasite can penetrate the skin of people wading, swimming, bathing, or washing in contaminated water. Within several weeks, worms grow inside the blood vessels of the human body and produce eggs and make the person sick. Unfortunately the cichlid which eats these snails has been overfished so the problem is growing.