Case report/Case history
A 28-year-old man with severe diarrhea and nausea visited our emergency room after consuming food at a restaurant, along with 31 colleagues; as per the survey of the staff at the Izumo Health Center, 10 out of 32 individuals developed acute gastrointestinal symptoms several hours after the meal (attack rate, 31.3%; incubation period ≈ 7 h; incubation distribution, 2–12 h) with diarrhea and nausea being the most common symptoms (60.0%), followed by abdominal pain (50.0%), and fever (40.0%); the average number of bowel movements per day was approximately six (range: 4–8), and mean temperature was 37.4 °C (range: 37.0–37.8 °C).
As all the patients had consumed sashimi prepared using juvenile PBT, food poisoning was suspected, and meal leftovers and stool specimens from the patients were submitted to the Shimane Prefectural Institute of Public Health and Environmental Science, Japan. PCR analysis revealed that four of the seven stool (three samples were missing) samples and leftover sashimi samples harbored Kudoa hexapunctata. In addition, Kudoa hexapunctata was observed microscopically in two samples collected from the leftover. (Fig. 1). No suspected food poisoning-related pathogens other than K. hexapunctata were detected in the stool samples. This diagnosis was made as all patients presented with transient diarrhea and vomiting, within a few hours of consuming sashimi containing juvenile PBT.