The latest cluster involves six secondary students who were part of a group of 36 teachers and students from a secondary school in the Kwun Tong district.
The exchange tour took place between March 13 and 15, during which the six students started developing symptoms.
Five of them sought medical attention in Xiamen, and none were hospitalised.
“Preliminary epidemiological investigations revealed that all six affected persons had not consumed any common food items other than the group meals and had no other common exposure history in Hong Kong prior to their departure,” the statement said.
“Hence, at this stage, the CHP could not rule out the possibility that the cases were infected by consuming contaminated food.”
The CHP is investigating the source of the outbreak and has collected stool specimens for testing, while also coordinating with mainland health authorities regarding the implicated restaurants.
The Education Bureau said it has instructed organising institutions to stop using the affected dining venues.
It has also reminded all organisers to immediately request that restaurants serving group meals refrain from offering high-risk foods like raw foods as well as cooked shellfish.
The bureau also said that that all participants of the tour have returned to Hong Kong.
Meanwhile, CHP said that three more students have developed gastroenteritis symptoms following an exchange tour to Shaoguan earlier this month, raising the total number of students and teachers affected to 55.
