Burgers that were recalled in Canada last week for potential E. coli contamination have now been linked to five illnesses, reported health officials Monday. The same strain of E. coli O157:H that was isolated from five patients in Alberta and Ontario was also found in Butcher’s Choice brand Garlic Peppercorn beef burgers, according to the Canadian Food Inspection Agency, reports CBC News. One lot of these burgers was recalled December 12, before the recall was expanded two days later to include all burgers of this variety. Two other types of frozen, pre-made beef patties  — Butcher’s Choice brand Hickory Barbecue and Cardinal Select brand Prime Rib Beef Burgers — were also recalled last week. All three burger varieties are manufactured by Cardinal Meat Specialists Ltd. of Brampton, Ontario. They are sold at Loblaw grocery stores across Canada. These two additional recalled products have not been linked to illnesses to date, reported the agency. Canadian health officials said they knew about these E. coli cases as early as October, but were not able to link them to a source until recently, according to CBC News. “The identification of a case of illness with no source of the particular food associated, while it triggers investigations, cannot lead to a recall at that time,” said Paul Mayers, vice president of programs for CFIA at a press conference Monday. “Indeed, we took samples of the Butcher’s Choice product at the time. All of those tests came back negative.”