Thirty-one tongues from apparently normal, freshly slaughtered pigs were assayed for the presence of Yersinia enterocolitica by different enrichment and postenrichment techniques. Sixteen different isolates were recovered, including six of serotype 0:8, four of serotype 0:6,30, two of serotype 0:3 phage type IXb, and one each of serotypes 0:13,7, 0:18, and 0:46. One isolate was not typable. Cold enrichment in phosphate-buffered saline followed by treatment with dilute KOH or subsequent enrichment in modified Rappaport broth recovered 12 and 7 isolates, respectively. Four of the same isolates were recovered from the same tongues by both procedures. Cold enrichment without a selective postenrichment treatment recovered two isolates. Direct enrichment in modified Rappaport broth or modified selenite broth was ineffective in recovering yersiniae, as no isolates were obtained by either method. All of the serotype 0:8 isolates were virulent to mice, causing the death of adults after oral challenge. This is the first report that associates Y. enterocolitica serotype 0:8 with a natural reservoir.

The role of Yersinia enterocolitica as a human pathogen has been documented in publications from over 30 countries, and Y. enterocolitica has been recognized increasingly to cause gastrointestinal disease in children. In 1979, an Australian survey yielded only three isolates of Y. enterocolitica from 3298 faecal specimens obtained from adults. We screened all stool specimens received during a 22‐month period for Yersinia by means of a recently developed selective agar medium. Y. enterocolitica was isolated from 32 of 4136 (0.7%) specimens. Most isolates were of serotype 0:3, biotype 4. During the study, 154 Salmonella spp. (3.7%), 196 Campylobacter spp. (47%), seven Shigella spp. (0.2%) and 27 Aeromonas spp. (0.9% of 2779) were recovered. Children infected with Y. enterocolitica presented with acute diarrhoea associated with fever and pharyngitis; chronic or recurrent diarrhoea; or pain in the right iliac fossa associated with mesenteric adenitis. Gastrointestinal symptoms usually resolved spontaneously within two weeks, however, some children were treated successfully with cotrimoxazole.