_____________________

Escherichia coli

Escherichia coli is a common and non-pathogenic bacterium found in the intestines of mammals. It is a gram-negative rod-shaped bacterium. There is, however, a strain that is pathogenic, and can cause a fatal infection in humans. Escherichia coli O157:H7 is unusually pathogenic in that it produces a powerful Shiga toxin. Although a minute percentage of people die of the estimated 70,000 infected each year, many must be hospitalized.

This illness was first recognized in 1982 from contaminated hamburgers from a restaurant. Undercooked beef is the most common source of infection. This strain lives in the intestines of healthy cattle, which can spread to the muscle tissue when slaughtered. Drinking unpasteurized milk can lead to this food poisoning. Also fecal material in water or unsanitary conditions may spread the disease. It is an easily contractible infection.

Symptoms include:

• fever,
• bloody diarrhea,
• abdominal cramps,
• and kidney failure.

	Escherichia coli can be contracted through beef and swimming in unsanitary swimming pools. Sometimes there are no symptoms and the illness passes after 5 to 10 days. Extra attention must be paid to young children and the elderly because a complication called hemolytic uremic syndrome can result from infection. This syndrome causes the red bloods cells to be killed and for the kidneys to fail.
Treatment for an infection may not be necessary. If anyone notices blood with diarrhea in their stool, they should get tested for Escherichia coli O157:H7. Most people recover without the use of antibiotics. In fact, in many cases, antibiotics do not improve the effects of the illness. Antidiarrheal medicine should also be avoided. People who develop hemolytic uremic syndrome, which is around 7% of E. coli infections, require more treatments. Often times they require the use of a dialysis machine and may have kidney complications.	_______

Prevention of infection can be maintained by:

	• thoroughly cooking ground beef. There is a greater chance of receiving the illness through ground beef rather than when eating a steak. Ground beef may come from a hundred different cattle, which in turn increases your odds of infection greatly, while a steak comes from only one cow.
• Make sure people wash their hands carefully when handling raw meat. • When preparing food in the kitchen involving raw meat, keep the meat separated from the rest of the food.	____________
• Do not use the same utensils on other food previously used with raw meat. There is no simple and quick way to tell if beef is contaminated because it looks and smells normal. • Wash fruits and vegetables well before eating because the people or animals that were in contact with them could spread the bacteria strain.	_________
• Infection can also spread between toddlers due to poor hygiene and hand washing routines. Parents and siblings who are often in contact with toddlers must be extra careful because it can pass through diarrheal stools. • Be sure to wash the hands of those who have been in a day care center. Even after someone recovers from the illness, it still passes through the stools for the next few weeks.
• Make sure that people with people with diarrhea wash their hands very carefully after using the restroom. • When swimming in a public pool or in a lake, avoid swallowing the water. • Prevention involves maintaining cleanliness, good hygiene, and caution in the kitchen.

References:
Bender JB, Hedberg CW, Besser JM, et al. Surveillance for Escherichia coli O157:H7 infections in Minnesota by molecular subtyping. N Engl J. Med 1997; 337:388-94.
Mahon BE, Griffin PM, Mead PS, Tauxe RV. Hemolytic uremic syndrome surveillance to monitor trends in infection with Escherichia coli O157:H7 and other shiga toxin-producing E.coli. Emerg Infect Dis 1997; 3:409-12.
Mead PS, Griffin PM. Escherichia coli O157:H7. Lancet 1998; 352: 1207-12.
Slutsker L, Ries AA, Greene KD, et al. Escherichia coli O157:H7 diarrhea in the United States: clinical and epidemiologic features. Ann Intern Med 1997; 126:505-13.
Boyce TG, Pemberton AG, Wells JG, Griffin PM. Screening for Escherichia coli O157:H7-a nationwide survey of clinical laboratories. J Clin Microbiol 1995; 33:3275-7.

BACK TO HOME