Test results revealed that Norovirus caused the gastrointestinal problems felt by more than 30 people at Camp Twin Echo, a facility operated by the Greater Pittsburgh Council of Boy Scouts of America.

Bob DeWitt, spokesman for the council, said 28 Boy Scouts and four adults became ill.

About 170 people attended the leadership training program at the camp, which ended Saturday. All of the affected people quickly recovered. Only one went home early.

Richard McGarvey, spokesman for the health department, said it’s likely that someone arrived at the camp already sick.