A formidable foe : malaria.

Malaria still remains a major threat to human life at the end of the 20th century, especially in Africa and tropical countries around the world. Nearly 400 million people are affected by malaria each year. Ancient Sanskrit medical texts described high fever caused by mosquitoes. Hippocrates associated intermittent fever with marshes. The film shows various stages of malaria: the initial cold and shivering stage; the rising temperature stage; the sweating fever stage. Dr. Ripley Ballou, Walter Reed Army Institute of Medical Research, USA, explains how parasites travel in the blood stream and multiply. The first effective treatment of malaria was discovered from barks of the Peruvian cinchona tree. Quinine extracted from cinchona bark was the only treatment for the African blackwater fever known as ague. By the 1950s malaria was eliminated from Europe and North America by draining marshes and providing better housing. In the 1940s DDT became widely available. It was sprayed inside the houses and on mosquito-breeding marshes which, along with quinine, effectively controlled malaria. Dr. Robert Gwadz, National Institute of Health, USA, and Samui Dadzie, Maxwell Appawu, Dr. Kwadwo Koram and Adeline Assoku, researchers at Noguchi Institute, Tokyo, talk about the search for a malaria vaccine which has gone on for over 30 years. In 1997, the Walter Reed team discovered a vaccine which, in experimental situations, proved to give protection to some volunteers. Small field trials are taking place in sub-Saharan Africa, especially in the Gambia. The film shows how the vaccine is developed. International efforts to find out which antigens create natural immunity continues. Dr. David Kaslow, U.S. National Institutes of Health, talks about a 'transmission blocking vaccine'. But scientists think it will be years before an effective vaccine can be created.