[Yersinioses].

The principal clinical syndromes caused by Yersinia (Y. pseudotuberculosis and Y. enterocolitica) are described. It is likely that they are zoonoses transmitted to man by ingestion. Fever, abdominal pain and diarrhea are the commonest symptoms, and patients are often operated upon for suspected appendicitis. The symptoms associated with these infections include arthralgia and erythema nodosum, particularly in adults. Most cases are benign, but some may be severe. Fortunately, however, many antibiotics are active against Yersinia. At present these diseases are uncommon in Switzerland but appear to be endemic in Scandinavia. Their relative incidence may increase if physicians become more aware of this possible etiology.