Yersiniosis Fact Sheet

October 2011

What Is Yersiniosis?

Yersiniosis is caused by the bacteria Yersinia enterocolitica (Y.enterocolitica). Infection with Y.enterocolitica can cause diarrheal illness. Yersiniosis is more common in young children. It is usually caused by eating contaminated foods, especially raw or undercooked pork products.

How Is Yersiniosis Spread?

People get infected by eating, drinking or touching and ingesting something that is contaminated with the bacteria. Raw animal foods may contain the bacteria and can cause illness if not properly cooked. Pork is the most common source of infection, but meat, poultry, raw milk, fish and seafood can also carry the bacteria. Y.enterocolitica can be spread to humans by infected puppies and kittens. Rarely, the bacteria can be transmitted through contaminated blood during a transfusion.

What Are the Symptoms of Yersiniosis Infection?

Symptoms of yersiniosis include:

• Fever
• Abdominal pain (the abdominal pain in older children and adults can mimic the pain of appendicitis)
• Diarrhea, which is often bloody

How Soon After Exposure to the Bacteria Do Symptoms Usually Start?

Symptoms usually begin 3 to 7 days after exposure to the bacteria. Symptoms can last for 1 to 3 weeks.

How Do I Know I Have Yersiniosis?

The signs and symptoms of yersiniosis are similar to other stomach infections. Yersiniosis can be confirmed through lab testing of stool samples.

How Is Yersiniosis Infection Treated?

Most individuals recover from their infection without medical treatment. It is important to drink extra fluids if you have diarrhea to prevent dehydration. For more serious infections, check with your healthcare provider who may prescribe antibiotics.

What Are the Possible Complications of Yersiniosis Infection?

Most people fully recover without complications. Some people may develop complications one month after infection including a red skin rash (erythema nodosum) and/or painful swelling of the joints in the knees, ankles and wrists (reactive arthritis). These complications resolve after 1 to 6 months. The bacteria can also spread to the blood where it causes a more severe infection.

Can I Still Go to School or Work If I Am Infected?

Yes. Most individuals with yersiniosis can continue with normal activities if they are well enough, but everyone is reminded that it is best to stay home when you are ill to reduce the risk of passing this infection to others. It is important that food handlers, healthcare workers and those who work or attend a childcare centre where there are children in diapers stay home and away from work or daycare for at least 24 hours after symptoms have gone away.

What Can Be Done to Prevent the Spread of Yersiniosis Infection?

There are a number of steps you can take to protect yourself and those around you:

• Thorough hand washing is the best prevention. Since the bacteria is passed in stool, the single most important prevention activity is careful hand washing after using the washroom, handling diapers, before and after preparing food and before eating and after handling pets, especially sick puppies and kittens.
• Do not prepare food for others if you have diarrhea.
• Keep raw foods cold until they are to be cooked. Refrigerate or freeze raw meat immediately after purchase.
• Prevent cross-contamination: separate raw meat and poultry from ready-to-eat foods at all times, including in the shopping cart, grocery bags, refrigerator and during preparation.
• Clean using soap and water and then sanitize all utensils and work surfaces with a mild bleach solution (5 ml/1 tsp. bleach per 750ml/3 cups water). Consider using a plastic cutting board. Place it in the dishwasher to disinfect.
• Drink only pasteurized milk.
• Cook meat and especially pork products thoroughly. Use a food thermometer to cook foods to a safe internal temperature.
• Wash fruits and vegetables thoroughly before eating.
• Drink water from a safe supply. If you drink water from a well, have it tested to ensure it is safe.

What Is the Role of Toronto Public Health in Investigating Yersiniosis?

Yersiniosis is a reportable communicable disease. Individuals residing in Ontario who test positive for yersiniosis must be reported to their local health department by either the lab or their healthcare provider. In Toronto, residents who are infected with yersiniosis will be reported to Toronto Public Health. Toronto Public Health will send a notice to you asking for additional information about your illness to help determine the source of your infection.

This information can be helpful in ensuring that contaminated food or water does not cause illness to other people.

More Information

Call Toronto Public Health at 416-338-7600 (TTY at 416-392-0658) or speak to your health care provider.