Foodborne, waterborne and soilborne diseases
Almost half the world's population suffers from diseases associated with insufficient or contaminated water and is at risk from waterborne and foodborne diseases, of which diarrhoeal diseases are the most deadly. They caused over three million deaths in 1995, 80% of them among children under age five. Typhoid fever causes about 16 million cases and over 600 000 deaths a year, about 80% of them in Asia. There are epidemics of cholera and dysentery, with cholera alone causing 120 000 deaths a year. Seventy-nine million people are estimated to be currently at risk of cholera infection in Africa. Worldwide, some 40 million people have intestinal trematode infections. However, dracunculiasis (guinea-worm disease) could be eradicated in the next few years; about 122 000 cases were reported in 1995 compared to 3.6 million in 1986.
Foodborne diseases have a major impact throughout the world. Estimates in the United States range from 6.5 million to 80 million cases a year. The leading foodborne bacteria worldwide are salmonellae, campylobacter, Escherichia coli and listeria. Foodborne viruses include hepatitis A, also common worldwide.
Soilborne infections affect several million people a year, intestinal worm infections being the most widespread. The most deadly soilborne disease is tetanus, which annually kills at least 450 000 newborn babies, and 50 000 mothers around the time of childbirth.