POTENTIAL SOURCES OF SPORADIC HUMAN INFECTION WITH YERSINIA-ENTEROCOLITICA SEROVAR-O 8 IN AOMORI PREFECTURE, JAPAN/

In November 1992 and June and August 1993 rectal contents from 204 sma ll mammals living in the wild were collected and examined for the pres ence of Yersinia enterocolitica serovar 0:8 to clarify the source of h uman infections caused by this microbe in the Tsugaru Region of Aomori Prefecture, Japan. Serovar 0:8 was isolated from 10 (5.2%) of 193 wil d rodents trapped in June 1993 (9 of 107) and August 1993 (1 of 23) bu t not from animals trapped in November 1992 (0 of 63), This serovar wa s not isolated from II moles, From May to September 1993, 12 human pat ients were found;to have become iii and to be infected with Y. enteroc olitica 0:8. The patients lived in the same districts where the, wild rodents harboring serovar 0:8 were trapped. Two different patterns by restriction enzyme analysis of the virulence plasmid were observed, On e pattern obtained by restriction enzyme analysis of the virulence pla smid was observed in 20 isolates from 11 human patients and 9 wild rod ents, and the other was observed in 2 isolates from 1 human patient an d 1 wild rodent. These findings indicate that wild rodents seem to pla y an important role as a source of human Y. enterocolitica 0:8 infecti on.