Escherichia coli, or E. coli, are bacteria found in the human gut. Most strains of E. coli are harmless; however, several can cause severe illness. Shiga toxinproducing E. coli (STEC) are bacteria that make a toxin that causes disease. STEC may also be referred to as Verocytotoxin-producting E. coli (VTEC) or enterohemorrhagic E. coli (EHEC). One strain in this group, EHEC O104:H4, caused a large outbreak in Germany in 2011.
STEC live in the guts of many animals that are typically not adversely affected by the bacteria. However, if humans drink water or eat fruits and vegetables contaminated with microscopic amounts of feces from these animals, they can become ill. Other means of transmission include eating contaminated or undercooked meat, drinking raw milk, drinking or swimming in contaminated water, working closely with cattle, touching the environment in petting zoos and other animal exhibits, eating food prepared by people who did not wash their hands well after using the toilet, or coming into contact with human feces.
The symptoms of STEC infection usually begin about 3 to 4 days after ingestion of the bacteria and include cramps, diarrhea (often bloody), vomiting, and fever. Most people recover within 5 to 10 days; however, a small percentage of infections lead to complications and fatal diseases. One of these diseases, hemolytic uremic syndrome (HUS), develops about 7 days after the initial symptoms and may result in acute kidney failure. Patients developing HUS often feel tired, urinate less, and lose facial coloring.
There is no treatment for E. coli infections other than staying well hydrated. Patients should not take antidiarrheals because diarrhea is important for removing the bacteria from the intestine. Antibiotics should also be avoided; they have not been found to be beneficial and may increase the risk of developing HUS.
Because E. coli is spread through animal and human feces, care should be taken to avoid consumption of products that may be contaminated. An easy way to prevent E. coli infections is by washing your hands with soap after using the bathroom and before working with or eating foods. E. coli can live in environments with temperatures up to 160°F (70°C); therefore, meats should be thoroughly cooked, and milk and juices should be pasteurized before consumption. After preparation of raw meat, wash your knives and cutting boards to prevent contamination of other foods that touch the same utensils. Drinking-water sources should be protected from animal waste, and drinking water that has not been tested for contaminants should be avoided. Finally, avoid swallowing water when swimming or playing in lakes, ponds, streams, swimming pools, and backyard “kiddie” pools.