The following is from The Bug Bible - http://www.safefood.net.au/AudienceHierarchy/TheBugBible/Default.htm

Yersinia enterocolitica has been recognized as an important cause of foodborne disease since the late 1980s. It is found in the general environment as well as the gut of various animals, and is associated more with the temperate regions of the world.

Many foods have been implicated as a vehicle or source of infection. While Y. enterocolitica has been isolated from a wide range of domestic and wild animals and birds as well as from environmental sources, pigs are directly or indirectly the main primary source of the pathogenic serotypes that cause infections in man.

Contaminated food or water is regarded as the main source of human infections and there is a close association with consumption of raw or undercooked pork.

Water vegetables and fresh herbs have been linked to sporadic cases.

Yersinia enterocolitica is a cold tolerant organism and will survive frozen for extended periods and grow at refrigeration temperatures. Growth is slowed below 5ºC. It is not heat resistant and is destroyed by pasteurization 72ºC for 18 seconds.

The organism will most likely come into the kitchen environment on pork and pork products. The following measures are important in controlling this organism in the kitchen environment:

• All pork should be adequately cooked prior to consumption.
• Raw pork should be covered and refrigerated below cooked foods. Any drip should be promptly cleaned up.
• Prevent cross-contamination from raw to cooked foods.
• Ensure that cleaning equipment like sponges and dishcloths are disinfected.
• Wipe up meat juices with disposable paper towels.
• Wash hands thoroughly frequently and particularly after handling raw meats.