Escherichia coli (E. coli)

The CDC estimates that between 7,600 and 20,400 people become ill and 120 to 360 people die each year from Escherichia coil (E. coli) infection. Found as a normal inhabitant of the intestinal tract, E. coli can nevertheless cause problems when fecal matter from cattle and infected humans gets into the food or water supply. Most infections have been linked with under-cooked meat, since contamination often occurs as a result of the meat coming into contact with the intestinal tract during the butchering of a carcass. Under-cooked hamburger is the most common meat source of E. coli contamination. Unlike a cut of meat where bacteria, if they are present, are usually on the surface, ground beef has had its surface mixed with the inside. A 1993 E. colt outbreak in a northwest fast food restaurant caused by the consumption of under-cooked ground beef brought about a prompt response from the U.S. government. A new safety program was instituted, featuring more rapid testing of ground beef, tighter controls at slaughterhouses and processing plants, and the labeling of fresh meat products with instructions for safe handling and preparation, including increasing final cooking temperature of ground meats from 140° to 160°F ,60° to 71°C). Health officials recommend that ground beef be cooked until no pink remains; even when thoroughly cooked, it should not touch any contaminated surface. Color is not the best criterion of doneness, however. Some ground beef is slightly brown even before being cooked, either from being temperature-abused, stored excessively long, or ground from the meat of older animals, and some contains seasonings or flavorings that cause the meat to stay pink well above its final recommended cooking temperature.

Undercooked hamburgers are not the only source of E. coli infection. Other foods or food-handling practices implicated in E. coli O157:H7 out-breaks include the following:

• Raw milk
• Un-pasteurized apple juice/cider
• Dry cured salami
• Fresh produce
• Produce from manure-fertilized garden
• Yogurt
• Sandwiches
• Water

E. coli may also be transmitted to children in childcare centers because of poor hand washing after diaper changing. Ideally, those who change the diapers should not be the same ones who prepare the food. Other outbreaks have been reported from an improperly chlorinated swimming pool and contaminated water systems. An increasing number of E. coli outbreaks involve fruits and vegetables. In one such case, fresh-pressed apple juice (cider) was made from apples that had fallen in cow manure, and in other cases fresh produce was contaminated with animal compost.

Certain strains of E. coli cause infant diarrhea, traveler’s diarrhea, and bloody diarrhea. E. coli may also cause hemorrhagic colitis - severe abdominal cramps, vomiting, diarrhea, and a short-lived fever followed by watery, bloody diarrhea - and hemolytic uremic syndrome (HUS), characterized by kidney dysfunction and the leading cause of acute renal failure in children; it can even result in death. Scientists began identifying E. coli 0157:H7 in the early 1980s, but it was not until the publicized outbreak in the Pacific northwest that national attention and preventative efforts were focused on the problem.