What is Yersiniosis?

Yersiniosis is an infection of the bowel caused by the Yersinia bacteria. There are two Yersinia species that cause infections of the human gut resulting in abdominal pain and diarrhoea. 

It is commonly caught from eating contaminated or poorly handled food. 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.

What are the symptoms?

Around 3 - 7 days after contact with the bacteria flu-like symptoms develop. Diarrhoea then develops, with severe abdominal pain. Nausea, vomiting and fever often occur. Yersinia infection usually lasts for 2 or 3 days, but can last for up to 3 weeks. Sometimes joint pains can develop. In a few people these are severe and disabling.

How are people infected?

People become infected when they swallow the bacteria. This can happen:

  • When handling food, especially undercooked pork or other meat, small goods or unpasteurised/raw milk
  • When drinking from an unsafe water supply e.g. roof or stream water
  • From contact with domestic or farm animals (including birds)
  • From contact with infected people, including children and babies.


How is it treated?

Usually extra fluid and rest are advised. However, a doctor should always be consulted and may recommend antibiotic treatment in selected cases.

How do I protect myself and others?

  • Avoid contact with infants, very elderly or ill people while you have diarrhoea.
  • Look after food carefully:
    • Thaw frozen meat completely
    • Cook meat and poultry thoroughly
    • Keep raw meat and poultry separate from other foods in the refrigerator
    • Store raw foods underneath cooked foods to prevent contamination
    • Clean knives, cutting boards and other surfaces after contact with raw meat and poultry
    • Don't handle food if you have diarrhoea - you could spread the illness
  • Remember to wash your hands:

    • After going to the toilet or changing nappies
    • After playing or working with animals
    • Before handling food
    • After touching raw meat or chicken

Do I need to take time off work, school or preschool?

  • Stay away from work, school or preschool when you have diarrhoea. 
  • Staff and children of early childhood centres should not return until they have been free from all symptoms for 48 hours.
  • People who work with food or in healthcare should not return until they have been free from all symptoms for 48 hours.


For more information about this illness contact a Health Protection Officer on 0800 221 555.