The trip took place this weekend and was arranged for the school's first-year students. Initially, around 60 people were reported to have fallen ill. Several of those affected were reportedly forced to relieve themselves in plastic bags during the trip home.
It is unclear exactly what made the people sick. Västervik Municipality is still awaiting results from samples taken from the food served during the trip.
"It can take many days of analysis and verification of certain parameters," writes the municipality's environmental and building manager Carolina Stalebrant to SVT.
