Chinese researchers are suggesting Canada’s first H5N1 flu patient may have contracted the bird flu virus passing through or near an illegal live bird market in Beijing.

Canadian scientists have published a report on the full genetic sequence of the virus taken from the Alberta woman, who died in early January after returning from a three-week trip to her native China.

The woman’s infection is a mystery. She spent her entire trip in Beijing, where H5N1 hasn’t been reported for some time, and her travelling companion says the woman did not have contact with live birds while she was there.

But scientists from Beijing’s Centre for Disease Prevention and Control are suggesting that illegal live bird markets may have been the source of the woman’s infection.

They say that even though Beijing banned live poultry markets in 2005, an illegal trade in live poultry continues in the city – and it’s possible the woman was infected while she was passing market stalls that sell live poultry.