Typhoid fever is contracted by drinking or eating the bacteria in contaminated food or water.
People with acute illness can contaminate the surrounding water supply through stool, which contains a high concentration of the bacteria. Contamination of the water supply can, in turn, taint the food supply. The bacteria can survive for weeks in water or dried sewage.
About 3%-5% of people become carriers of the bacteria after the acute illness. Others suffer a very mild illness that goes unrecognized. These people may become long-term carriers of the bacteria - even though they have no symptoms - and be the source of new outbreaks of typhoid fever for many years.
Keyword: causes typhoid fever