Community outbreak of Yersinia pseudotuberculosis

An outbreak of Yersinia pseudotuberculosis in Kurashiki, Japan is described. This is the first conclusive report of a community outbreak of this microorganism. A total of 535 pupils, five teachers, and one food attendant contracted the organism. Causative organisms were detected in 19 out of 30 patients. All isolated strains belonged to serotype VA. Out of 653 sera of the pupils, 488 showed elevated agglutinin titers ranging from 1:80 to 1:1,280 or more within a period of 3 months.