The role of Yersinia enterocolitica in appendicitis in the southwestern United States.

Infection with Yersinia enterocolitica had been associated with acute appendicitis in approximately six per cent of patients in northern European countries. However, the incidence of Y. enterocolitica in patients with appendicitis in this country is uncertain. Therefore, this study was undertaken to ascertain whether Y. enterocolitica is a possible infectious agent in appendicitis in the southwestern United States. Fifty prospective patients (35 men and 15 women) with an average age of 22.3 years (range 3 to 62 years) underwent appendectomy for presumed appendicitis. Portions of each specimen were cultured for Y. enterocolitica with highly selective media (Cefsulodin-Irgasan-Novobiocin [CIN] agar). Pathologically, 44 of the patients had appendicitis and 6 patients had normal appendices. Four of the 44 patients (9.1%) with appendicitis were found to be culture positive for Y. enterocolitica, while it was recovered from none of the normal appendices. This indicates that Y. enterocolitica may represent the major pathogen in acute appendicitis in a small, but distinct, portion of indigent patients within Los Angeles County as it does elsewhere in the world.