A hospital in Lloydminster, Sask., has been reusing syringes to inject medication into intravenous lines, a practice that recently raised widespread concern in Alberta.

On Thursday, the province's chief medical health officer, Dr. Moira McKinnon, confirmed that Lloydminster Hospital has been reusing syringes this way. The border-town hospital serves patients from both Alberta and Saskatchewan.

Saskatchewan's Ministry of Health has launched an investigation to determine whether other health regions are also reusing syringes. Health officials said they don't know how long the practice has been going on. Nor can they say how many patients may have been exposed to risk.

"The risk, as I said, is extremely low and we've got experts working on exactly what that risk is," said McKinnon.

"We will move to testing if that's necessary, if the risk shows that that's necessary."

In the meantime, McKinnon has issued a cautionary alert to the province's health regions about reusing syringes.

Although needles should be used only once, the risk of acquiring an infection from a syringe used twice in an IV line is exceptionally low, McKinnon said.

"You're not actually penetrating the patient, you're only putting it into a tube that follows down to the patient's arm. There is a theoretical risk that there can be some back flow of that blood and contamination, but it's a theoretical risk only," she said.

On Friday, the Canadian Patient Safety Institute said the provinces should work together to find out what happened and look at the risk to patients.

It's understanding … what has actually gone on, what has happened, understanding exactly the process and the risks associated with contamination," said the institute's chief executive, Philip Hassen.

"That needs to be done very, very carefully and very quickly so that we can then determine what patients, if any, are at risk and what you do about it."

The Alberta government issued a similar alert Thursday, saying it had discovered another instance of a health professional practising in Saskatchewan and Alberta who had reused single-use syringes to administer medication through an IV line.

"We know that a physician who practises in the Lloydminster and Vermilion hospitals has been administering multiple doses of medication through IV lines to multiple patients," Alberta Health and Wellness said in a release.

Earlier this week, tests were ordered for thousands of people who received treatment in High Prairie, Alta., after it was learned that a hospital there had been reusing syringes for years.

The province said it learned nurses at the High Prairie Health Complex had been routinely injecting drugs into patients' intravenous lines with the same syringe.

Alberta Health Services said it would be contacting patients by phone and registered mail for followup blood testing. Patients will be tested for HIV and hepatitis B and C.

With files from the Canadian Press