Atypical Yersinia enterocolitica: clinical and epidemiological parameters

Abstract

Infections due to biochemically typical Y. enterocolitica usually present as gastroenteritis, mesenteric lymphadenitis, terminal ileitis and septicemia often with visceral abscesses. In these instances, the isolates were biochemically typical and of well-established serotypes, namely 0:3 or 0:9 and, in the USA, 0:5 or 0:8. The recovery, recognition and significance of biochemically and serologically atypical Y. enterocolitica in human infections proceeded more slowly. From an analysis of the clinical histories of 20 patients infected with 21 such aberrant Y. enterocolitica, it appears that these strains are of restricted pathogenic potential, producing various clinical entities such as localized skin abscesses, conjunctivitis, self-limiting enteritis, and wound and urinary tract infections in hosts with predisposing factors. Epidemiologically, whereas episodic acquisition of atypical strains by hospitalized patients is indicative of nosocomial transmission, in the present series sporadic isolations over a 4-yr period, mainly from ambulatory patients, suggest an occult reservoir in the community serviced by The Mount Sinai Hospital [New York, New York, USA]. In contrast to typical Y. enterocolitica, which has become well adapted in animal and human hosts, it appears that environmental strains may be in the evolutionary process of becoming adapted to humans.