Yersinia enterocolitica

Yersinia enterocolitica is a bacterium that can be found in animals such as pigs, birds, beavers, cats and dogs, and has been detected in environmental sources such as soil and water (e.g., ponds and lakes). It is not part of the normal human flora.

Y. enterocolitica grows well at low temperatures and can withstand freezing and survive in frozen foods for extended periods. Thus, Y. enterocolitica can grow easily at refrigerated temperatures in vacuum-packed meat, boiled eggs, boiled fish, pasteurized liquid eggs, pasteurized whole milk, cottage cheese, and tofu.



Infection caused by Y. enterocolitica results in a “relatively infrequent cause of diarrhea and abdominal pain,” according to the federal Centers for Disease Control and Prevention (CDC).  When it occurs, it is most often caused by eating contaminated food, especially raw or undercooked pork products,  The preparation of raw pork intestines (chitterlings) has been associated with outbreaks . Infants can be infected if their caretakers handle raw chitterlings and do not adequately clean their hands before handling the infant or the infant’s toys, bottles, or pacifiers.  Drinking contaminated unpasteurized milk or untreated water can also transmit the infection. Occasionally Y. enterocolitica infection occurs after contact with infected animals. On rare occasions, it can be transmitted as a result of the bacterium passing from the stools or soiled fingers of one person to the mouth of another person. This may happen when basic hygiene and hand washing habits are inadequate.

The incubation period for Y. enterocolitica typically ranges from one to 11 days, but in rare circumstances can last for several months. The most common symptoms of infection with Y. enterocolitica are diarrhea, fever and abdominal pain, but in some circumstances it may lead to autoimmune complications such as reactive arthritis.

Children under the age of five are most likely to have symptomatic infections. The illness most often lasts for a few days to three weeks. Most mild cases of yersiniosis resolve without treatment, but health professionals can prescribe antibiotics to treat it, if necessary.

Incidence of Illness

CDC monitors the frequency of Y. enterocolitica infections through the foodborne disease active surveillance network (FoodNet). In addition, CDC conducts investigations of outbreaks of yersiniosis to control them and to learn more about how to prevent these infections. CDC has collaborated in an educational campaign to increase public awareness about prevention of Y. enterocolitica infections.

According to CDC data, yersiniosis infection is relatively rare with 158 cases from all food sources reported in 2011 compared to 7,763 reported cases of Salmonella. Of those reported cases, 56 required hospitalization.  Most importantly, data show that Yersinia infections have declined in recent years.

Industry and Government Efforts to Reduce Yersinia on Meat

Meat plants use a variety of food safety practices and technologies to prevent Yersinia on meat products.  Strategies include scrupulous sanitation, sanitary dressing procedures, carcass washes, knife sterilization and more.  Declines in cases of yersiniosis suggest that efforts to enhance meat safety are contributing to these declines.

USDA’s Food Safety and Inspection Service (FSIS) oversees and inspects meat packing and processing continuously and monitors efforts to prevent bacteria contamination.  Only meat and poultry products deemed to be in compliance with federal requirements may bear the USDA inspection mark and enter commerce.

Preventing Yersiniosis

Strains of Y. enterocolitica can be found in meats (pork, beef, lamb, etc.), oysters, fish, crabs, and raw milk. However, the prevalence of this organism in soil, water, and animals, such as beavers, pigs, and squirrels, offers many opportunities for Yersinia to enter the food supply. For example, poor sanitation and improper sterilization techniques by food handlers, including improper storage, may be a source of contamination.

Thorough cooking of all meat and poultry products is always critical in ensuring that food is safe.  Fresh, whole muscle cuts like chops should be cooked  to 145 degrees Fahrenheit with a three minute rest period.  Ground meat products should be cooked to 160 degrees F.  In addition to thorough cooking, proper safe food handling techniques include washing hands with soap and water before eating and preparing food, after contact with animals, and after handling raw meat; using separate cutting boards for meat and other foods; and keeping food refrigerated at 40°F or lower.  The Food and Drug Administration inspects imported foods and milk pasteurization plants and promotes better food preparation techniques in restaurants and food processing plants. The Department of Agriculture monitors the health of food animals and is responsible for the quality of slaughtered and processed meat. The Environmental Protection Agency regulates and monitors the safety of our drinking water supplies.

Third Party Experts

Scott Hurd, Ph.D., DVM
Associate Professor and Director of Graduate Education
Veterinary Diagnostic & Production Animal Medicine
Food Risk Modeling and Policy Lab
Iowa State University
(515) 294-7905

John Sofos, Ph.D
Department of Animal Science
Colorado State University
(970) 491-7703

Keith Belk, Ph.D.
Center for Meat Safety & Quality
Department of Animal Sciences
Colorado State University
(970) 491-5826