Septicaemia due to Yersinia enterocolitica biotype I in Hong Kong

The clinical histories of four patients with septicaemia due to Yersinia enterocolitica biotype I and the biochemical reactions of the isolates are reported. Three of the isolates were serotype 017 and one was non-typable. These are the first reports of Y. enterocolitica septicaemia from Asia and of septicaemia due to biotype I which has previously been postulated to be non-pathogenic. All four patients had an underlying illness (two with metastatic neoplasms and two with burns). All of the patients recovered fully despite the high mortality associated with this condition. It is postulated that biotype I is of low pathogenicity.