First N America H5N1 bird flu death confirmed in Canada

China has been vaccinating poultry against the H5N1 virus

Canadian health officials have confirmed the first known fatal case of the H5N1 avian influenza strain in North America.

Canadian Health Minister Rona Ambrose said the deceased person was an Alberta resident who had recently travelled to Beijing.

Calling the death an "isolated case", Ms Ambrose said the risk to the general population was low.

Ten people have died in Alberta this season from swine flu, or H1N1.

H5N1 infects the lower respiratory tract deep in the lung, where it can cause deadly pneumonia.

The World Health Organisation (WHO) says it is difficult to transmit the virus from person to person but when people do become infected, the mortality rate is about 60%.

In the latest incident, the infected person first showed symptoms of the flu on an Air Canada flight from Beijing to Vancouver on 27 December, officials said.

The passenger continued on to Edmonton and on 1 January was admitted to hospital where they died two days later.

Dr Gregory Taylor, deputy chief public health officer for Canada told CBC News Network that the patient was relatively young, with no underlying health conditions.

People usually most susceptible to H5N1 are older with underlying health problems which make them weaker and less able to deal with the virus.

Ms Ambrose said Canadian officials were working with Chinese authorities on the case. But she stressed: "The risk of getting H5N1 is very low. This is not the regular seasonal flu. This is an isolated case."

Canadian authorities have followed up with all close contacts of the infected person and offered Tamiflu as a precaution. None of them have symptoms.

They said the infected person had not been to a poultry farm or had much contact with birds whilst they were in Beijing, so it is unclear how they caught the virus - which is usually contracted through very close contact between infected bird and humans.

According to the WHO, between 2003 and December 2013 there were 648 confirmed human cases of H5N1 infection in 15 countries, leading to 384 deaths.

Experts say that if the H5N1 virus were to mutate and become easily transmissible between humans, the consequences for public health could be very serious.

Timothy O'Leary, a WHO spokesperson, said the organization would not be changing its risk assessments on H5N1 in view on this development.

He said: "It usually takes two to eight days for symptoms of H5N1 to show up. So if anyone else were infected then we'd probably know about it by now.

"There is reason to be concerned but this appears to be an isolated case. It was imported from outside of northern America. We would be surprised if there were any cases related to this one from China. It's hard for people to get it."

Prof Nick Phin, a flu expert fro Public Health England, said: "H5N1 has been circulating in poultry over the last decade and occasionally humans are infected.

"Infection of humans causes severe illness with a high death rate, but the virus does not transmit readily from person-to-person."