B.C. warns doctors to watch for avian flu spreading to humans after spike in cases in birds

The B.C. Centre for Disease Control is asking doctors to be on the lookout for the unlikely possibility of highly pathogenic avian influenza spreading to humans after a recent spike in outbreaks on commercial farms in the Fraser Valley.

According to the Canadian Food Inspection Agency, there have been 48 sites in the region with infections involving the H5N1 subtype of the virus since Nov. 16.

A Dec. 2 communicable disease advisory from the BCCDC warns of "severe illness" among wild and domesticated birds.

"While HPAI [highly pathogenic avian influenza] does not typically infect humans, the increase in detection among birds over the last two weeks increases the potential for exposure and transmission to humans who, if infected, may experience symptoms of varying severity," the advisory says.

"Exposure to novel influenza viruses is concerning because of the potential for human adaptation and associated pandemic risk. Such risk may be considered a 'low probability, high impact' event."

So far, four human cases of the virus have been detected in North America and Europe, including one in the U.S., one in the U.K. and two in Spain.

The BCCDC says the possibility of avian influenza should be considered in patients who've had close contact with infected animals. Symptoms are similar to other cases of flu and could include cough, sore throat, fever, runny nose, fatigue, muscle pains, joint stiffness, headache, pink eye, shortness of breath and seizures.

British Columbians are being advised to avoid unnecessary contact with both domestic and wild birds, make sure eggs and poultry dishes are well cooked, stay away from surfaces contaminated with bird droppings, boil untreated water from areas where wild birds gather and get an annual flu shot.

Theresa Burns, B.C.'s chief veterinarian, said that this fall's outbreak is linked to migratory waterfowl like geese and ducks moving from north to south through the province.

"This is the largest outbreak that we've seen in British Columbia, and certainly, it's also the largest outbreak that we've seen globally," she told CBC.

She added that this year's strain is much more infectious than what is typically seen and causes more serious illness in poultry.