An outbreak of Campylobacter jejuni subsp. jejuni infection via tap water.

*Corresponding author: Mailing address: Aizu Branch of Fukushima Institute of Public Health, 7-40 Oute-machi, Aizuwakamatsu, Fukushima 965-0873, Japan. E-mail: abe_tamaki_01@pref. fukushima.jp A total of 71 patients demonstrating abdominal pain, diarrhea, and fever were reported to Kooriyama City Health Center and Aizu Health Center in Fukushima Prefecture, Japan, in August 2006. All the patients had been drinking tap water supplied by a small village in the town of Inawashiro (Fig. 1), and there were no foods commonly eaten by the patients. The health center found that the tap water had not contained chlorine for about a week due to the failure of a chlorine injection system, and that the pace of incoming patients peaked during that time. It was suspected contaminated tap water was the source of this outbreak of food poisoning. Thirteen stool specimens of patients, and samples of original untreated water from a spring, treated water at the filtration plant, and tap water in a patient’s home were investigated by the Fukushima Institute of Public Health and at the Aizu Branch of the institute. Campylobacter jejuni strains were isolated from 11 stool specimens and from the original untreated water. Confirmation of the C. jejuni was done by biochemical analyses and multiplex PCR (Fig. 2). Serological tests indicated that all of the isolates belonged to the Z6 serotype. Further, all isolates from the stool samples and from the water demonstrated the same pattern by SmaI-digested pulsed-field gel electrophoresis (Fig. 3). It was concluded that C. jejuni originally present in the water was the cause of