Types of yersinia
The 2 types of yersinia we talk about on this web page are:
- Yersinia enterocolitica
- Yersinia pseudotuberculosis
Their symptoms are almost the same and if you follow our food safety tips, it should keep you safe from both.
Yersinia enterocolitica infection
Symptoms vary between younger children, older children, and adults.
For children under 5 years old, symptoms include:
- diarrhoea
- vomiting
- fever and, less commonly, abdominal pain.
Older children and adults are more likely to experience abdominal pain as the predominant symptom, with pseudo appendicitis for older children.
Blood poisoning (infection of the blood) and other complications may occur in immunocompromised individuals.
Illness usually lasts 2 to 3 days, but it can go on for up to 3 weeks.
Yersinia pseudotuberculosis symptoms
- Abdominal pain (often on the lower right), that may mimic appendicitis.
- Fever.
- Sometimes diarrhoea, rash, and joint pain (appearing 1 to 3 weeks later and lasting up to 6 months).
- In rare cases, blood poisoning (infection in the blood) occurs, although this is more common in people with weakened immune systems.
How you can get sick from yersinia
Yersinia infections occur by contact with infected faeces, eating or drinking contaminated food or water, or contact with contaminated soil or infected animals, especially pigs.
High-risk foods include raw or undercooked pork meat and foods containing pork meat (for example, dumplings, sausages, and burgers).
Other high-risk foods are raw milk and raw vegetables.
Some other foods have also been responsible for outbreaks in other countries, for example, tofu, shellfish, fish.
How to lower your risk of getting sick from yersinia
Yersinia multiply quickly in warm, moist conditions, so it's important to store or refrigerate food properly to minimise bacteria growth. Unlike a lot of other bacteria, Yersinia can also multiply at the fridge's temperature, but more slowly than at warm temperatures.
Food handling tips to lower your risk
- Ensure food is properly cooked and still hot when served.
- Avoid raw milk and products made from raw milk.
- Wash fruit and vegetables carefully, especially if they'll be eaten raw.
- If you’re unsure about the safety of drinking water, boil it.
- Wash hands thoroughly and often with soap. Do this especially before and after handling risk foods, or after contact with pets or farm animals, or after going to the toilet.
Older people, sick people, younger children, and pregnant women should avoid high-risk foods.
Avoid cross-contamination
Harmful germs can spread to different food and surfaces. For example, if you cut raw pork meat then use the same knife and chopping board for other food, the germs can spread. This can increase the risk of getting sick. This is called cross-contamination.
To help avoid this, separate foods to prevent germs from spreading. Use different chopping boards and knives, and wash your hands.
Find out more about cross-contamination and how to avoid it
Find out more
Yersiniosis – Ministry of Health
Who to contact
If you have questions about yersinia, email info@mpi.govt.nz
