Yersinia pseudotuberculosis

Yersinia pseudotuberculosis is a bacteria that can cause acute stomach illness. Yersinia pseudotuberculosis is normally rare in New Zealand.


There are 3 Yersinia species that cause illness in humans.

The other species are:

  • Yersinia enterocolitica – this is a more common cause of stomach illness in humans
  • Yersinia pestis – this is the organism which causes plague. It hasn’t been reported in New Zealand since 1911.

How it’s spread

If you’ve been infected with Yersinia pseudotuberculosis, it usually takes 5–10 days for the symptoms to develop (but sometimes up to 21 days).

Animals and humans can both get Yersina pseudotuberculosis. It can be spread by:

  • contact with infected faeces (poos)
  • eating or drinking contaminated food or water
  • contact with contaminated soil and infected animals.

Foods that have been known to cause outbreaks of Yersinia pseudotuberculosis include raw grated carrots, lettuce and contaminated chocolate milk.

The disease can still be present in faeces weeks after the symptoms have gone.


The first symptoms of Yersinia pseudotuberculosis include:

  • abdominal pain (often on the lower right), which may mimic appendicitis
  • fever
  • sometimes diarrhoea.

About 1–3 weeks later, you may get a rash and joint pain. The joint pain can last up to 6 months.

In rare cases Yersinia pseudotuberculosis infection can lead to sepsis (infection in the blood). This is more common in people with weakened immune systems.

See your doctor, or call Healthline on 0800 611 116 for advice if you think you might have Yersinia pseudotuberculosis. There’s a laboratory test which can check for the disease.


Yersinia pseudotuberculosis is normally rare in New Zealand.

These tips can help you protect your family from Yersina pseudotuberculosis and other foodborne illness.

  • Wash fresh fruit and vegetables before eating.
  • Avoid eating raw or undercooked meat.
  • Only use pasteurized milk or milk products.
  • Wash hands with soap and water:
    • before eating and preparing food
    • after contact with animals
    • after visiting the toilet
    • after changing nappies
    • after handling raw meat.
  • Prevent cross-contamination in the kitchen by:
    • using separate cutting boards for meat and other foods
    • carefully cleaning all cutting boards, counter-tops and utensils with soap and hot water after preparing raw meat.
  • Dispose of animal faeces in a sanitary manner.
  • More information on food safety is available on the Food Safety NZ website.
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