Per CDC:
KEY POINTS
Yersinia are bacteria (germs) that can make you sick.
Infection with Yersinia is often linked to eating raw or undercooked pork.
Symptoms depend on the age of the person with the infection.
Overview:
Yersinia are bacteria (germs) that can make people ill.
Two kinds of Yersinia can cause diarrhea. They are:
Yersinia enterocolitica
Yersinia pseudotuberculosis
The illness these kinds of Yersinia can cause is called yersiniosis.
Causes:
People can get infected after swallowing Yersinia. Children are more likely to get Yersinia infection than adults.
Common causes of infection:
Contaminated food, especially raw or undercooked pork
Contact with a person who has prepared a pork product, such as chitlins
Keep in mind:
Germs can spread from hands to infants and toddlers. If you've been preparing food, be sure to wash your hands well before touching a child or a child's bottles, pacifiers, or toys.
Handwashing tips
Less common causes of infection:
Drinking contaminated milk or untreated water
Contact with animals, their environments, or their poop
Contact with another person (for example, by not washing hands thoroughly after changing the diaper of a child with an infection)
For more information visit: About Yersinia Infection | Yersinia Infection | CDC