[A diffuse outbreak of enterohemorrhagic Escherichia coli O157:H7 related to the Japanese-style pickles in Saitama, Japan].

We have experienced an outbreak of enterohemorrhagic E. coli O157:H7 (Shiga-like toxin 1 & 2 producing) in child independence support facilities in the all dormitory system, in Saitama August 2001. There were 13 patient and EHEC O157s were detected in a total of 29 specimens. As a result of epidemic inspection and microbiological investigation. We recognized that the causative food was Japanese-style pickles named "Wafu-Kimuchi" which had been sold in Saitama and Tokyo area. As the same period, several infections caused by EHEC O157 were considered the same origin in Saitama (8 patients in 5 families). Furthermore some infections happened also in Tokyo. It was made clear this outbreak was a part of a diffuse outbreak caused by Wafu-Kimuchi. In diffuse outbreaks, it is important to grasp a common feature of the individual cases in a wide area. The exchange of epidemic information between two or more municipalities and the guess of the identity in the DNA levels of strains were the key role to the elucidation of this case.