Life cycle The parasite responsible for bilharzia has a life cycle which is dependent on an intermediate host-a common species of water snail-for transmission to the final host. Eggs from the mature parasite are continually excreted by infected persons or animals. If they reach water, they hatch into an intermediate form which seeks out a snail host. In the snail, after further transformations, the parasite begins to release numerous 'cercariae' the form which affects man. These cercariae can penetrate skin, so any contact with infected water is enough to transmit the disease. Bilharzia can be controlled by eradicating the snails by keeping humans (and their waste) away from water bodies that could be infected. Treatment itself is of little value for even if all human carriers were temporarily cured, the parasite population could be maintained by infected animals. Even if all affected communities were provided with safe water, washing facilities and toilets, farmers and fishermen would still be vulnerable and children would still swim in rivers. So in practice, snail eradication has to be the focal point of any control programme. Activity 2.4: Instruction: Answer the following questions in your group. 1. Make notes on the ideas in the above two paragraphs. Then, a) How do express the life cycle of bilharzia in one or two sentences?​