Faecal carriage rate of Yersinia species.

A total of 1,203 unselected routine faecal samples from 1,006 patients were cultured for Yersinia species by a cold enrichment technique. Seventy-five specimens (6.1%) from 63 patients were culture-positive for Yersinia spp. Fifty-two were Yersinia enterocolitica, 22 Yersinia frederiksenii and 1 Yersinia intermedia. The predominant Y. enterocolitica isolates belonged to biotype 1 - serotype 0:6, 30 or serotype 0:5, 27. Y. frederiksenii strains were non-typable. Forty isolates were recovered from 33 patients with gastroenteritis. During the study period 83 Salmonella spp. from 33 patients, 17 Shigella sonnei from 13 patients and 13 Campylobacter jejuni from 12 patients were cultured. Yersinia spp. was isolated in association with salmonella on three occasions, twice with rotavirus and once each with Shigella sonnei, Campylobacter jejuni and Trichuris trichiura.