Yersiniosis is an infectious disease caused by a germ (bacteria). Most human illness is caused by the species Yersinia enterocolitica. Pigs are the main animal that carries the strains that cause human illness. However, other strains are also found in other animals. Yersiniosis is not very common. It is more common in children than adults. It is more likely to occur in the winter.


Most often, infection is caused by eating contaminated food, especially raw or undercooked pork products. Infection can also occur:

  • In infants if their caretakers handle raw pork or other animal products and do not properly clean their hands before touching the infant, toys, bottles, or pacifiers.

  • From drinking contaminated, unpasteurized milk or untreated water.

Less commonly, infection can occur:

  • After contact with infected animals.

  • When bacteria are passed from the stool or soiled fingers of one person to the mouth of another person.

  • From receiving contaminated blood during a transfusion.


Infection with this bacteria can cause a variety of symptoms. Problems depend on the age of the person infected. Common symptoms in children are:

  • Fever.

  • Abdominal pain.

  • Diarrhea, which is often bloody.

Symptoms usually begin 4 to 7 days after exposure. They may last 1 to 3 weeks or longer.

In older children and adults, the main symptoms are right-sided abdominal pain and fever. These problems may be confused with appendicitis. Rarely, patients can develop skin rash, joint pains, or the bacteria can spread to the bloodstream and other organs.


This diarrheal illness is often diagnosed when the bacteria is detected in the stool. Most labs do not routinely test for this bacteria, so special tests may need to be done. If infection spreads out of the bowel, the bacteria may also be detected in other sites such as the throat, lymph nodes, joint fluid, urine, bile, and blood.


Uncomplicated cases of this diarrheal illness often resolve on their own. In more severe or complicated cases, medicines that kill germs (antibiotics) may be useful.


  • Avoid eating raw or undercooked pork.

  • Consume only pasteurized milk or milk products.

  • Wash hands with soap and water before eating and preparing food, after contact with animals, and after handling raw meat.

  • Prevent cross-contamination in the kitchen. Use separate cutting boards for meat and other foods. Carefully clean all cutting boards, countertops, and utensils with soap and hot water after preparing raw meat.

  • Dispose of animal feces in a sanitary manner.


  • Follow all your caregiver's instructions.

  • If you are infected, wash your hands with soap and water before preparing food for others.

  • Only take over-the-counter or prescription medicines for pain, discomfort, or fever as directed by your caregiver.


  • Symptoms seem to be getting worse rather than better or new symptoms develop.

  • You have questions or concerns.