E. coli O157:H7

E. coli bacteria are commonly found in human and animal feces. They are a good indicator that sewage contamination has occurred. Like many other bacteria, they are transferred via the fecal-oral route, when contaminated feces is ingested by another person, and may cause illness in humans.

E. coli O157:H7 bacteria are the most virulent strain of E. coli bacteria.

Once ingested, the E. coli O157:H7 bacteria grow in the intestine and produce a toxin which causes severe abdominal pain, and watery diarrhea, with little or no fever. Learn more about diarrheal infections.

The young and elderly are more likely to develop hemorrhagic colitis (gastrointestinal bleeding caused due to colon inflammation). They may also experience a reduction in red blood cells, reduction in platelets (clotting agents) and acute kidney failure.

These complications may cause death.

E. coli O157:H7 is sometimes present in contaminated water. It is more commonly found on raw meats (poultry, pork, ground meat) that may have been contaminated in the slaughtering process. Raw (unpasteurized) milk is another potential source of E. coli O157:H7.

There is no real treatment except for supportive care, such as avoiding dehydration. Drink plenty of fluids and monitor the illness for signs of dehydration.

Signs of dehydration include:

• thirst
• dry lips and mouth
• dark coloured urine with a foul smell
• headache
• lack of energy
• dizziness
• flushed skin
• increased heart rate

• wash hands after using the toilet and before preparing foods
• clean and sanitize counter-tops and utensils after contact with raw meats and poultry, especially before using these areas for preparation of ready-to-eat foods
• if possible, separate work areas for preparing raw and cooked foods
• cook meats thoroughly to safe internal cooking temperatures (Government of Canada)
• drink only pasteurized milk
• never let children sample raw milk from an animal
• drink water from a safe (potable) supply
• avoid preparing or handling food if you have diarrhea
• keep cold foods at 4° C or less
• keep hot foods at 60°C or more
• in a hospital or institutional setting isolate individuals with diarrhea and follow proper infection prevention and control practices