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.