Skip to content


Reportable Disease Toolkit Badge

Reporting Obligations

Confirmed and suspected cases shall be reported to the local Health Unit.

Reporting Form Button


Aetiologic Agent

Yersiniosis is caused by a Gram-negative enterobacteriacae of the genus Yersinia. Two species, Y. entercolitica (most common in Canada) and Y. pseudotuberculosis, are the causative agents of yersiniosis.

Clinical Presentation

Y. entercolitica infections typically manifest as fever and diarrhea in young children. Stool often contains leukocytes, blood and mucus. In older children and adults a pseudoappendicitis syndrome, with fever, abdominal pain, tenderness in the right lower quadrant of the abdomen and leukocytosis predominates.

Y. pseudotuberculosis presents with fever, scarlatini-form rash and abdominal symptoms and acute pseudo-appendicieal abdominal pain is common. Clinical features can mimic those of Kawasaki disease.

Complications include post infection arthritis and systemic infections.

Modes of Transmission

Fecal-oral transmission via contaminated food and water or by contact with infected people or animals, such as puppies and kittens; raw pork and pork products are known sources of infection.

Strains of Y. enterocolitica can be found in meats (pork, beef, lamb, etc.), oysters, fish, and raw milk. There are many opportunities for Yersinia to enter the food supply due the prevalence of this bacterium in soil, water, and animals. Poor sanitation, improper storage, or poor sanitizing practices by food handlers may also be a source of contamination.

Y. enterocolitica persists longer in cooked foods than in raw foods, due to increased nutrient availability. Y. enterocolitica can grow easily at refrigeration temperatures in vacuum-packed meat, boiled eggs, boiled fish, pasteurized liquid eggs, pasteurized whole milk, cottage cheese, and tofu. Growth of the microorganism also occurs in refrigerated seafood – oysters, raw shrimp, and cooked crab meat. Outbreaks, worldwide, have been associated with milk, tofu and pork chitterlings.

Nosocomial transmission of Y. enterocolitica has occurred, as has transmission by transfusion of stored blood from donors who were asymptomatic or had mild gastrointestinal illness.

Incubation Period

Probably 3–7 days, generally less than 10 days.

Period of Communicability

Secondary transmission appears rare; fecal shedding occurs as long as symptoms persist, usually 2–3 weeks; if untreated, persons may shed 2–3 months; prolonged asymptomatic carriage has been reported.

Risk Factors/Susceptibility

Diarrhea is more severe in children; complications in adolescents and older adults are more severe and septicemia occurs more often in people with iron overload or immunosuppression.

  • Consumption of raw/unpasteurized milk/milk products
  • Consumption of potentially contaminated water
  • Consumption of raw/undercooked pork/pork products
  • Animal contact (pets, farm animals, petting zoos)
  • Failure to wash hands after handling raw pork/meat
  • Poor hand hygiene
  • Travel outside the province/country

Diagnosis and Laboratory Testing

Diagnosis is usually made through stool culture. Stool cultures generally are positive during the first two weeks of illness. Enteric culture specimens are accepted only from health units at the Public Health Lab. If you are a clinician, please use a community laboratory to perform your testing. Confirmation and speciation performed at Public Health Lab.

Y. entercolitica and Y. pseudotuberculosis can be recovered from stool, throat swabs, mesenteric lymph nodes, peritoneal fluid, and blood. Y. entercolitica also has been isolated from synovial fluid, bile, urine, cerebrospinal fluid, sputum and wounds.

Testing Information and Requisition Button

Treatment and Case Management

Treatment is under the direction of the attending health care provider. Contact precautions are indicated for diapered or incontinent children and hospitalized cases for the duration of diarrheal illness. Provide personal preventative measures (thorough cooking and safe handling of meats; proper hand hygiene practices after toileting, handling meat or animals; only consume pasteurized milk and milk products). Inform patients that symptomatic cases will be excluded from conducting activities in high-risk settings such as the food industry, healthcare, or daycare until at least 24 hours after cessation of diarrhea or 48 hours after completion of antibiotic therapy or anti-diarrheal medications. Advise household members who are symptomatic to seek medical care.

Patient Information

Patient Fact Sheet Button

Additional Resources

Heymann, D.L. Control of Communicable Disease Manual (19th Ed.). Washington, American Public Health Association, 2008.


Ministry of Health and Long-Term Care, Infectious Diseases Protocol, 2022.