What is yersiniosis?

Yersiniosis is a disease caused by bacteria called Yersinia. Three different species of Yersinia can cause illness in humans. These are Y. pestis, which causes plague, and Y. enterocolitica and Y. pseudotuberculosis, both of which cause gastrointestinal illness. This fact sheet provides information on the illnesses that are caused by Y. enterocolitica and Y. pseudotuberculosis.

Who gets yersiniosis?

Anyone can get yersiniosis, but it is identified more often in infants and children than in adults.

Where are Yersinia found?

Yersinia often live in animals, particularly pigs and therefore can be found in pig products. Usually the animals carrying the Yersinia bacteria are not sick. In addition to pigs, other animals carry Yersinia, including rodents, rabbits, sheep, cattle, horses, dogs, and cats. 

How are Yersinia bacteria spread?

  • By eating contaminated food, especially raw or undercooked pork products. The preparation of raw pork intestines (chitterlings) may be particularly risky because of the risk of cross- contamination.
  • Infants can be infected if their caretakers handle raw chitterlings and then do not adequately clean environmental surfaces and their hands before they handle the infant or the infant’s toys, bottles, or pacifiers.
  • By drinking contaminated unpasteurized milk or untreated water.
  • By contact with animals carrying the bacteria on their bodies.
  • As a result of the bacteria passing from the stools or soiled fingers of one person to the mouth of another person due to inadequate hand washing habits.
  • Through contaminated blood during a transfusion. This is extremely rare.

What are the symptoms of yersiniosis?

Infection with Y. enterocolitica can cause a variety of symptoms depending on the age of the person infected. Common symptoms in children are fever, abdominal pain, and diarrhea, which is often bloody. In older children and adults, right-sided abdominal pain and fever may be the predominant symptoms, and may be confused with appendicitis. They may also develop a skin rash and joint pains. Spread of the bacteria through the bloodstream to other parts of the body can occur, but it is very rare.  Young children and persons with weakened immune systems may have a more severe illness. Infection with Y. pseudotuberculosis is rare in the United States, but that species causes similar symptoms.

How soon after exposure do symptoms appear?

Symptoms typically develop three to seven days after exposure, and may last one to three weeks or longer.

How is yersiniosis diagnosed? 

Yersiniosis is generally diagnosed by laboratory tests that detect the bacteria in the stool. In people seriously ill with yersiniosis, the Yersinia may be found in blood and other body sites.

What is the treatment for yersiniosis?

Most people with yersiniosis recover on their own. Persons with diarrhea should drink plenty of fluids to prevent dehydration. Antibiotics are generally not recommended unless the illness is severe.

How can yersiniosis be prevented?

  • Wash hands with soap and water before preparing and eating food and after handling animals.
  • Prevent cross-contamination in the kitchen. Use separate cutting boards for meat and other foods. Carefully clean all cutting boards, counter-tops, and utensils with soap and hot water after preparing raw meat.
  • Be sure the pork and pork products that you eat are cooked thoroughly and milk and milk products are pasteurized
  • Use special care when preparing chitterlings. Using pre-cooked chitterlings is preferred; raw ones should be pre-boiled for five minutes before cleaning and cooking.
    • Follow instructions for cleaning and preparing the chitterlings.
    • Keep infants and children away from the kitchen while chitterlings are being prepared.
    • When finished, clean all kitchen surfaces, cutting boards and utensils thoroughly. Wash hands and fingernails carefully with soap and water before touching anything else in the kitchen and before handling infants or their toys, bottles, or pacifiers.
  • Dispose of animal feces in a sanitary manner.

How long can an infected person carry and shed Yersinia bacteria?

People carry the bacteria at least as long as symptoms exist, usually for two to three weeks. Untreated patients may shed the bacteria for two to three months. 

Should a person infected with Yersinia be excluded from work or school?

  • People with diarrhea should remain away from work or school until they have been without diarrhea for 24 hours. Young children with diarrhea should not go to child care centers.
  • Most infected people may return to work or school when the diarrhea stops, as long as they are careful to wash their hands with soap and water after using the toilet and before preparing food.
  • In some situations, people who are carrying Yersinia may be excluded from high-risk settings until follow-up stool cultures are negative for Yersinia. The local health department will determine when it is safe for the person to return to work or other normal activities.

How can I get more information about yersiniosis?

February 2018