Health officials say they have confirmed the steaks that made four people sick in Edmonton originated from an XL Foods plant and were sold at a Costco store in the northeast part of the city.

CIFA is recalling beef steaks sold at the northeast Edmonton Costco under the Kirland brand. (CIFA)

The steaks were sold at the Costco store on 50th Street and 136th Avenue under the Kirkland brand and were contaminated with E. coli.

Alberta Health Services (AHS) linked the striploin grilling steaks with four cases of E. coli illness announced last week.

"We know the food source. What we don’t know at this point is the source of the contamination," said Dr. Gerry Predy, Alberta's senior medical health officer.

He said health officials were able to link the illness to the store after testing a steak provided by one of people who became sick.

The Canadian Food Inspection Agency has issued a health alert over the meat but it is still unclear how and where the meat became contaminated.

The steaks were sold between Sept. 4 and Sept. 7, and are marked with one of the following "Packed On" dates:

• 12 / SE / 04
• 12 / SE / 05
• 12 / SE / 06
• 12 / SE / 07

Consumers are urged to check meat they have in their freezers to see if it is covered by the alert.

Predy said AHS isn't releasing any information on the condition of those who got sick.

"Because of the small number of cases, we aren’t releasing any information … that could violate their privacy."

Tenderization process may be to blame

Predy said during their investigation, it was discovered that Costco stores across the province used a tenderization process that may have played a role in the E. coli illnesses.

The stores would run steaks through a machine that would strike them with a meat tenderizer with a needle-like surface.

Predy says if E.coli bacteria was on the surface of the meat, the process may have forced it deeper into the steak, where it would be more difficult to kill while cooking.

“Our public health message has been that if you’re eating steak, it’s OK to eat it rare,” said Predy.

“If this process is going to be used, then the public needs to know it has been used so the public can use necessary precautions."

He said the process doesn’t violate health codes, but AHS has asked stores in the province to stop using the machines as a precaution.

Steaks came from Brooks plant

The steaks came from the XL Foods processing plant near Brooks in southern Alberta, said Canadian Food Inspection Agency spokesperson Tim O'Connor.

That's the same facility where 250 ground beef products have been recalled from stores across the country.

No direct link between E. coli illnesses and the plant has been established, said O'Connor.

"There are many steps in-between and, while it is possible, we cannot say conclusively at this time that that [facility] is the source of contamination," he said.

In a statement, XL Foods said it is co-operating with the CFIA and AHS in their investigations.

The company said a recent review of its operation found two "deficiencies" that could have played a part in the contamination. It says it has since changed those procedures.

"Food safety is simply too important to our customers, our employees and our business," the company wrote.

Richard Arsenault, director of meat inspection for the CFIA, says investigators believe that cows carrying higher-than-normal amounts of the E.coli bacteria entered the plant at the end of August.

“The controls in the plant are designed to deal with normal. This was an outlier."

Arsenault says increased sampling and testing has made the meat inspection more accurate in recent years. He says now the problem is that the data isn't being analyzed as well as it should be.

"The issue isn’t the number of inspectors. The issue isn’t if the inspectors were doing their job properly," he said.

“We need to do a better job of managing this data and finding these trends ahead of time … as opposed to having to respond to a crisis like this.”