Questions and Answers

What are Yersinia?

Yersinia are bacteria that can cause illnesses in humans.

What are Yersinia enterocolitica?

Y. enterolitica are the most common species causing human enteric (intestinal) yersiniosis.

Pigs are the major animal reservoir for the few strains of Y. enterocolitica that cause human illness, but rodents, rabbits, sheep, cattle, horses, dogs, and cats also can carry strains that cause human illness.

What is yersiniosis?

Yersiniosis refers to the illnesses caused by Y. enterocolitica and less often by Y. pseudotuberculosis infections.

What are the symptoms of yersiniosis?

The symptoms of yersiniosis depend on the age of the person infected. Infection occurs most often in young children. Common symptoms in children are fever, abdominal pain, and diarrhea, which is often bloody. Symptoms typically develop 4 to 7 days after exposure and may last 1 to 3 weeks or longer. In older children and adults, right-sided abdominal pain and fever may be the predominant symptoms and may be confused with appendicitis. Complications are rare, and may include skin rash, joint pains, or spread of bacteria to the bloodstream.

How do people get yersiniosis?

Most people become infected by eating contaminated food, especially raw or undercooked pork, or through contact with a person who has prepared a pork product, such as chitlins. For example, babies and infants can be infected if their caretakers handle contaminated food and then do not wash their hands properly before handling the child or the child’s toys, bottles, or pacifiers. 

People occasionally become infected after drinking contaminated milk or untreated water, or after contact with infected animals or their feces.

On rare occasions, people become infected through person-to-person contact. For example, caretakers can become infected if they do not wash their hands properly after changing the diaper of a child with yersiniosis.

Even more rarely, people may become infected through contaminated blood during a transfusion.

How common is yersiniosis?

CDC estimates that infections with Yersinia enterocolitica cause almost 117,000 illnesses, 640 hospitalizations, and 35 deaths in the United States every year. Children are infected more often than adults, and the infection is more common in the winter.

How is yersiniosis diagnosed?

Yersiniosis usually is diagnosed by detecting the bacteria in the stool of an infected person. Many laboratories do not routinely test for Yersinia, so it is important that the clinician notifies the laboratory when yersiniosis is suspected so that special tests can be done.  

How is yersiniosis treated?

Yersiniosis usually goes away on its own without antibiotic treatment. However, antibiotics may be used to treat more severe or complicated infections.

Are there long-term consequences of yersiniosis?

Most symptoms go away completely. However, some people may experience the following:

• Joint pain, called reactive arthritis, most commonly in the knees, ankles, or wrists. These joint pains usually develop about 1 month after yersiniosis illness begins and generally goes away after 1 to 6 months.
• A skin rash, called "erythema nodosum," on the legs and torso. The rash is more common in women and usually goes away within a month.

How can I help protect myself and my family from infection?

• Avoid eating raw or undercooked pork. Learn more about the safe minimum cooking temperature for pork.  
• Consume only pasteurized milk and milk products, such as soft cheese, ice cream, and yogurt. Find out about the dangers of raw milk.
• Wash hands thoroughly with soap and water before eating and preparing food, after contact with animals, and after handling raw meat. See how handwashing can help keep you healthy.
• After handling raw chitlins, clean hands and fingernails carefully with soap and water before touching infants or their toys, bottles, or pacifiers. Someone other than the person handling food should care for children while chitlins are being prepared. Get more tips on staying safe when preparing chitlins.
• Prevent cross-contamination in the kitchen by using one cutting board for raw meat and another cutting board for fresh produce. Carefully clean all cutting boards, countertops, and utensils with soap and hot water after preparing raw meat. Learn four simple steps to food safety.
• Dispose of animal feces (poop) in a sanitary manner. Get tips to help keep you and your pets healthy.

What are public health agencies doing to prevent and control yersiniosis?

Many agencies work together to prevent and control yersiniosis: 

• Public health departments investigate outbreaks of yersiniosis to stop them, and to learn more about how to prevent infections. 
• CDC and public health departments have conducted educational campaigns to increase people’s awareness about yersiniosis and how to prevent infection, especially while preparing chitlins.  
• CDC monitors Y. enterocolitica infections through the Foodborne Disease Active Surveillance Network (FoodNet).
• The U.S. Food and Drug Administration inspects imported foods and milk pasteurization plants and promotes good food preparation techniques in restaurants and food processing plants. 
• The U.S. Department of Agriculture monitors the health of food animals and is responsible for the quality of slaughtered and processed meat.
• The U.S. Environmental Protection Agency regulates and monitors the safety of drinking water supplies.

 Top of Page