Commonly referred to as E. coli, Escherichia coli is a bacterium that is typically found in a number of environments including various foods, soil and animal intestines. E. coli is very diverse and belongs to the genus Escherichia.
Most types of E. coli are harmless and even help keep your digestive tract healthy. But some strains can cause diarrhoea if ingested.
E. coli not only causes food poisoning, you can also get pneumonia and urinary tract infections from the different types of the bacteria. In fact, 75% to 95% of urinary tract infections are caused by E. coli. Some versions of E. coli make you sick by making a toxin called Shiga. This toxin damages the lining of your intestine. The strains of E. coli that make the toxin are sometimes called STEC, which is short for “Shiga toxin-producing E. coli.”
O157:H7 is an especially bad strain of E.coli and can make you very sick. It causes abdominal cramps, vomiting and bloody diarrhoea. It is the leading cause of acute kidney failure in children. It can also cause life-threatening symptoms such as:
- Adult kidney failure
- Fever
- Bleeding
- Confusion
- Seizures
These symptoms are life-threatening and if displayed immediate emergency medical help must be sought.
Transmission (Infection)
You can become infected through the ingestion of E. coli bacteria. Among the ways this can happen:
Minced-meat: You eat ground meat that carries E. coli, and the meat wasn’t cooked enough to kill the bacteria. When meat is processed, sometimes bacteria from the animals’ intestines make their way into the meat. This happens more with ground meat because it comes from more than one animal.
Untreated milk: You drink unpasteurised milk, which hasn’t been heated to a temperature that kill bacteria. E. coli can get into the milk from the cow’s udder or from milking equipment.
Vegetables and fruit: You might eat fresh vegetables or fruit that’s been contaminated by water that has the bacteria. This happens most often when manure from nearby animals mixes with the water supply.
Other foods and beverages: You might also get E. coli from unpasteurised fruit juices, yogurt and cheese made from raw milk.
Water: You swallow water that contains E. coli, perhaps while swimming in a pool, lake, or pond.
Other people: You might get E. coli from another person who has it, such as a child. The bacteria can be passed to you if you clean up after an infected person and then don’t wash your hands really well before you touch your mouth.
Animals: It can be found at petting zoos or animal exhibits at fairs.
At home: You can also contaminate food in your own kitchen if you allow a knife or cutting board that has touched uncooked meat (like chicken) to come into contact with food that will be eaten raw (like a salad).
Symptoms
Symptoms usually appear 2 to 5 days after you’ve ingested the E. coli bacteria. The most common symptoms are:
- Abdominal cramps
- Diarrhoea, which may be bloody
- Nausea
- Constant fatigue
You may have a slight fever. Healthy people infected with E. coli usually feel better within a week, while others can develop a serious complication called haemolytic uraemic syndrome, which affects the kidneys. This is more likely to happen to older people and children.
Treatment
Before treatment can commence, the E.coli bacterium must first be confirmed as the causative agent of the illness. Confirmation is done by a laboratory analyses of the patient’s stool sample. The infection usually goes away on its own.
For some types of E.coli associated with diarrhoea, such as the watery travellers’ diarrhoea, antibiotics can shorten the length of time you have symptoms and might be used in moderately severe cases.
But if you have fever, bloody diarrhoea or if your doctor suspects Shiga toxin-producing E. coli, antibiotics should not be taken. They can actually increase the production of Shiga toxin and worsen your symptoms.
It’s important to rest and get plenty of fluids to replace what your body is losing through vomiting or diarrhoea.
Don’t take over-the-counter medications that fight diarrhoea. You don’t want to slow down your digestive system, because that will delay your body’s shedding of the infection.
When you start to feel better, stick to low-fibre foods at first such as toast, eggs and rice.
Dairy products and foods that are high in fat or fibre can make your symptoms worse.
Prevention
One of the most important things you can do to protect yourself and your family against E. coli is wash your hands, particularly in these situations:
- Before you prepare food
- Before preparing bottles or food for infants or toddlers.
- Before touching anything, such as a dummy, that goes into a small child’s mouth.
- After you’ve used the bathroom or changed a nappy.
- After you’ve had contact with animals, even your own pets.
- After handling raw meat.
You can also prevent E. coli infections by being careful about the foods that carry the greatest chance of contamination:
- Cook burger patties until they’re 71 degrees Celsius inside.
- Drink only pasteurised milk, juice, and cider.
- Wash all of your produce before you eat it. Be especially careful to get dirt off leafy greens such as lettuce and spinach.
In your kitchen, a couple of simple rules will help keep you safe:
- Wash: Clean knives, counters, and cutting boards with hot, soapy water after raw meat has touched them.
- Keep raw and cooked separate: Use different cutting boards for food that you eat raw, such as vegetables and fruit. Don’t put cooked meat back on the same plate you used for raw meat without washing the plate first.
- Swimming: When you’re swimming, try not to swallow the water, whether it’s a pool, a lake, or the ocean. It may be contaminated.
PREVENTING FOOD POISONING:
Wash your hands, utensils and food surfaces.
Separate raw and ready-to-eat foods.
Cook foods at safe temperatures.
Keep cold foods cold and hot foods hot.
Refrigerate or freeze perishable foods promptly.
Defrost foods safely.
SOURCES:
CDC: “E. coli.”
Johns Hopkins Health Library: “Escherichia coli O157:H7,” “Escherichia coli.”
National Institute of Allergy and Infectious Disease: “E. coli.”
Mayo Clinic: “Diseases and Conditions — E. coli.”
KidsHealth.org (Nemours Foundation): “E. coli.”
World Health Organization: “E. coli Fact Sheet.”
Chris Hayhurst (2004) E. Coli.