Canada on Wednesday reported its first case of Tamiflu-resistant A/H1N1 flu virus, in a man who had been given the drug to prevent infection.

A 60-year-old man from Quebec province was given the flu antiviral after his son fell ill with the pandemic virus. But he came down with the flu anyway. It was believed the resistance arose in his body.

But he recovered quickly and did not require hospital treatment. There is no evidence he transmitted the resistant virus to anyone else.

A man leaves a school, attended by children from the five new confirmed cases of influenza A (H1N1), after collecting a box of Tamiflu in south London May 4, 2009. [Xinhua/Reuters]

 This is the world's fourth such case since the new A/H1N1 virus was discovered in April. Japan has since reported its second case, the world's fifth such case.

Jirina Vlk, spokesperson for the Public Health Agency of Canada, said on Wednesday the Quebec man's case appears to be an isolated one of Tamiflu resistance, adding her agency continues to be vigilant for similar cases.

Tamiflu is sometimes given to prevent infection but has been seen, on occasion, giving rise to resistant viruses, said Dr. Allison McGeer, an influenza expert at Toronto's Mount Sinai University.

She said given the amount of Tamiflu being used in the world right now, such cases are bound to arise. She said either the cases would continue to arise sporadically or there will be widespread Tamiflu resistance, and there is not much middle ground.

(Xinhua News Agency July 23, 2009)