Distribution of Yersinia pseudotuberculosis in Japan and Epidemiology of Human Infection

Experiments were performed and reviewed literatures about the isolation and serotyping of Yersinia pseudotuberculosis in Japan and epidemiology of human infection with the organisms.A total of 421 strains, 224 strains from human, 191 strains from 11 species of animals, 1 strain from pork and 5 strains from drinking waters, were examined. Latent infection is frequent in cattle, swine, dog, cat and rat, whereas monkey, goat, rabbit and guinea pig were diseased. The organisms were divided into 12 serovars. The most of strains belonged to serovar 4b, followed by serovars 3, 1b, 5b and 5a.The monthly prevalence of human infection was showed a higher incidence in colder months, November to May. Human infections with the organism were concentrated in 1 to 16 year old, with peak in the 1 to 3 year old. No relationship between serovar and sex-age incidence, and clinical manifestation was found.Some characteristics were noted about hosts and serovars of Y. pseudotuberculosis and age incidence of the infection in Japan compared with those of European countries.