The Public Health Protection Unit of NHS Greater Glasgow and Clyde, Health Protection Scotland, Food Standards Agency and Glasgow City Council Environmental Health is investigating these cases.
Initial investigations indicate that there is a link to the Hydro, and an association with the consumption of burgers, but other foods items are also being considered.
The unit said in a statement: “If anyone has attended the Hydro between Friday January 17th and Saturday, January 25th and has experienced, or is continuing to experience, symptoms including stomach cramps, diarrhea (often bloody), nausea and fever they should contact a GP or NHS out of hours service.”
All 11 cases are recovering at home. One case is from Greater Glasgow and Clyde, three are from Lanarkshire, four from Lothian, one from NHS Highland, one from Forth Valley and one from Cumbria.