[PulseNet Japan--network system for the utilization of epidemiological information and the results of pulsed-field gel electrophoresis].

Since 1996, we have been analyzing DNA pattern of enterohemorrhagic Escherichia coli(EHEC) O157: H7 isolates in Japan by the use of pulsed-field gel electrophoresis. The method, capable of discriminating genotypical difference of the isolates, enabled us to find the contaminated food such as salmon roe which was the causative agent for the multiprefectual outbreaks in Japan. These outbreaks which we are referring as diffuse outbreaks seem to be increasing in number, because it reflects that some of widely distributed or mass-produced food products are being contaminated by pathogens such as EHEC. In order to find a diffuse outbreak promptly and prevent it becoming large, we are constructing a network, called PulseNet Japan, for sharing the results of pulsed-field gel electrophoresis and epidemiological information among municipal public health institutes and National Institute of Infectious Diseases.