For the first time, scientists have identified fresh produce as
the source of an outbreak of human Yersinia pseudotuberculosis
infections, according to an article published in the March 1
issue of The Journal of Infectious Diseases, now available
online. The outbreak was identified in Finland and traced
epidemiologically to farms producing lettuce. Y.
pseudotuberculosis, first identified in 1883, causes infections
characterized by fever and abdominal pain that are often
confused with acute appendicitis. The microbe is well known in
veterinary medicine as the cause of illnesses in hares, deer,
and sheep, among other animals. Y. pseudotuberculosis infections
in humans are relatively rare, and while foodborne transmission
has long been suspected, attempts to trace the pathogen to a
concrete source of contamination in the past have been
unsuccessful. In October of 1998, two microbiology laboratories
in southern Finland discovered an alarming increase in
infections during routine surveillance of laboratory-diagnos