Yersiniosis is a bowel infection caused by the Yersinia bacteria. It is usually caught from eating contaminated or poorly handled food, often pork.

Other sources are infected household pets and farm animals – especially pigs. Untreated water, or an infected person who handles food, can also spread Yersinia bacteria.

Yersiniosis causes flu-like symptoms, diarrhoea (runny poo), and severe abdominal (stomach) pain. Sometimes joint pains can develop, and for some people this pain can be severe and disabling.

If you are concerned about yersiniosis, call Healthline on 0800 611 116 or see your doctor or practice nurse.

People become infected when they swallow the Yersinia bacteria.

This can happen:

  • when handling food, especially undercooked pork or other meats and small goods
  • when consuming unpasteurised (raw) milk
  • when drinking from an untreated water supply, such as roof, tank or bore water
  • from contact with domestic or farm animals
  • from contact with infected people.

Yersiniosis is not usually serious, and most people recover quickly without having to see a doctor. If the symptoms are severe, a person may need to go to hospital, particularly if they are very young or elderly and get dehydrated (their body doesn’t have enough fluid to function properly).

Between one to 11 days after contact with the bacteria, flu-like symptoms develop. Diarrhoea then starts, with severe abdominal (stomach) pain. Nausea, vomiting and fever often occur.

Yersinia infection usually lasts for two or three days, but can last for up to three weeks. Sometimes joint pains can develop, and in a few people these are severe and disabling.

To prevent against yersiniosis

Look after food carefully:

  • thaw frozen meat completely
  • cook meat thoroughly
  • keep raw meat separate from other foods in the refrigerator
  • store raw foods underneath cooked foods to prevent cross contamination
  • thoroughly clean knives, cutting boards and other surfaces after contact with raw meats.


If you have yersiniosis

If you have yersiniosis you will need to avoid close contact with infants, the elderly or ill people, until you have been symptom free for 48 hours.

You should not donate blood within three months of Yersinia infection, as it can be transmitted through blood transfusions. If you have had a bloodstream infection with Yersinia (blood poisoning or sepsis/septicaemia) you should not give blood for six months.

To reduce the risk of spreading yersiniosis you should also wash and dry your hands carefully:

  • after going to the toilet or changing nappies
  • before handling food
  • after touching uncooked meats
  • after contact with domestic animals or pets



It's recommended you drink lots of fluids and get plenty of rest if you have yersiniosis. If your symptoms are severe you should contact your doctor. You can also call Healthline for free anytime on 0800 611 116.

Yersiniosis is a notifiable disease. This means that health professionals or laboratories will inform us when someone has it. This allows us to monitor the number of people who have the disease and give health professionals advice on how to reduce its spread.

People with yersiniosis who work in jobs where it could be easily spread, such as working with food, or in childcare or health care, will be contacted by us so we can talk to them about how to stop others from getting sick.


There are specific requirements for notifiable diseases in the Auckland region.

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Last updated 23.11.2022

For health advice call Healthline for free anytime on 0800 611 116
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