Escherichia coli (E.coli)

E. coli are common germs (bacteria) normally found in the gut of warm-blooded animals and people.

There are many types of E. coli, most of which are harmless and are an important part of a healthy human intestinal tract. However, some types can cause illness.

One type of disease-causing E. coli is known as Shiga-toxin producing E. coli or STEC. This may also be referred to as Verotoxin E. coli (VTEC).

The types of E. coli that can cause illness can be transmitted through contaminated water or food, or through contact with infected animals or people. It usually takes between 2–10 days after the bacteria are ingested for the first symptoms to appear.

Symptoms of STEC infection

The symptoms of STEC infection varies for each person but often include:

  • severe stomach cramps
  • mild to severe diarrhoea (which may be bloody)
  • vomiting.

If there is fever, it usually is not very high (less than 38.5˚C).

Most people recover within 5–7 days. Symptoms are generally mild in healthy people, however, they can be severe in children, the elderly, and people with reduced immunity.

Complications of STEC infection

Around 8–10% of those who are diagnosed with STEC infection develop a potentially life-threatening complication known as hemolytic uremic syndrome (HUS) which affects the kidneys and bloodstream.

How is STEC spread?

Illness due to STEC occurs through:

  • eating contaminated raw food
  • drinking unpasteurized (raw) milk
  • drinking contaminated water
  • contact with infected animals
  • contact with the faeces of infected people.

STEC cases in New Zealand

STEC is a notifiable disease in NZ. In 2013 there were 207 cases of STEC in New Zealand and 20 paediatric cases of HUS reported.

STEC testing in New Zealand

In New Zealand screening for STEC is done by community laboratories. Positive cases are confirmed by testing at ESR.

More information

If you have concerns about someone that is unwell, please call your GP, practice nurse or Healthline 0800 611 116 for free health advice. Healthline is a free 24-hour telephone health information service for all families.

For more information on food safety and foodborne illnesses, go to Bacteria and viruses in food on the Ministry for Primary Industries website.

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