All but one of those affected by E. coli live in Scotland, with one living in Cumbria. All are said to be recovering at home.
Last week, NHS Greater Glasgow and Clyde (NHSGGC) said seven cases had been identified, with four more confirmed on Monday and a further four today.
Investigators are looking particularly at the three days between January 17 and 19 at the Hydro, but advised anyone who visited the venue between January 17 and 25 and has experienced symptoms including stomach cramps, diarrhea, nausea and fever to contact their GP.
The shows at the complex during the period were Top Gear, Del Amitri and Celtic Connections.
Two of the cases are from the greater Glasgow area, three are from Lanarkshire , five from the Lothian area, two from the Highlands, two from the Forth Valley and one from Cumbria.