Dr. Gerry Predy speaks about Alberta's first case of drug-resistant swine flu at a news conference in Edmonton Tuesday. (CBC)

Alberta has confirmed its first case of drug-resistant swine flu, provincial health officials announced Tuesday.

The case involved a woman who was treated for swine flu last month. She was not hospitalized but was given oseltamivir, commonly known by its trade name, Tamiflu.

She was being treated and monitored for another undisclosed medical condition. The drug-resistant H1N1 strain was only confirmed in the last couple of days after additional testing was done at the National Microbiology Laboratory in Winnipeg.

"If you have a resistant strain obviously it will affect the efficacy of the treatment and you have to know, if you're going to treat the individual, whether or not they are resistant," said Dr. Gerry Predy, the senior medical officer of health for Alberta Health Services,

"But again, because most people with H1N1 develop mild illness and they won't be treated with antivirals, it's really not significant to the majority of people who get infected with H1N1."

Provincial officials will investigate whether the patient had the drug-resistant strain when she first became sick, or if it developed while she was being treated for the other condition.

Predy would not say what part of the province the woman is from. She is now recovering and is no longer displaying symptoms. Health officials will do follow-up testing to confirm whether she is free of the virus. They also monitoring people she has come in contact with.

Other isolated cases are being reported around the world. In July, a 60-year-old Quebec man was discovered to have a strain of swine flu that was resistant to Tamiflu. The man recovered without requiring hospital treatment.