What Canada is doing to monitor H5N1 bird flu

A teenager in British Columbia diagnosed with bird flu is the first domestically acquired human case of H5N1 bird flu, the Public Health Agency of Canada says.

Because influenza A or flu viruses are named after the animal where they are most commonly found, avian viruses are naturally found in birds.

H5N1 is a highly transmissible and usually mild disease in geese, swans and gulls, as well as domestic birds such as chickens and turkeys. It has also spread to mammals.

Scientists at the National Microbiology Laboratory in Winnipeg have sequenced the genome of the infected BC teen's virus to confirm it is H5N1. The tests showed the version of the virus is related to the bird flu viruses from the ongoing outbreak in British Columbia's poultry, the Public Health Agency of Canada said Wednesday.

The version is not the same as the one spreading among dairy cattle in the US, PHAC added.

What are the risks for humans?

The H5N1 form of bird flu remains a virus that mainly occurs in birds.

“Based on current evidence, the risk of avian influenza infection to the general public remains low at this time,” PHAC said. “The risk of infection with bird flu is greater for those who have unprotected exposure to infected animals.”

That's why officials are encouraging people who work closely with livestock, such as poultry and dairy farmers, to wear personal protective equipment such as goggles, masks and gloves.

In British Columbia, provincial health officer Dr. Bonnie Henry said at a press conference on Tuesday that people can become infected by 'inhaling the virus in aerosols, in droplets that end up in the eyes, at the back of the throat, nose or deep in the lungs. .”

The only known human case in Canada involves a teenager in B.C. who is in critical condition, Henry said. About three dozen people who were in contact with the teen have been tested for the virus and none have evidence of infection.

Globally, “there are very few that have been transmitted from person to person, so in some ways this is reassuring because this virus does not seem to spread easily between people if they get infections. But it also causes very serious diseases. , especially in young people,” Henry told reporters.

Henry said it's very likely the BC teen's infection occurred due to exposure to a sick animal or something in the environment, but it's a “real possibility” that investigators will never determine the source.

What are some ways to try to stay safe?

Since the spring of 2022 millions of poultry birds have been culled in Canada to contain an outbreak of highly pathogenic avian influenza (HPAI), including flocks in B.C.'s commercial poultry sector.

'One of the important things we need to do now, recognizing that this virus is circulating among wild birds, especially geese and ducks, is to make sure that if you come into contact with sick birds or dead birds, “Don't touch them directly,” Henry advised.

This is also recommended to people keep pets away from dead birds since pets, including a dog recently in Ontario, became infected by biting or eating a dead bird.

“If you have flu-like symptoms you should report it to a healthcare provider immediately and if you have been in contact with sick animals you should especially emphasize this so that appropriate testing can be done,” says Dr. Brian Conway, medical specialist. director of the Vancouver Infectious Diseases Centre, proposed.

How was the human case identified in BC?

Dr. Theresa Tam, Canada's chief public health officer, noted that the detection was picked up through hospital surveillance. People with respiratory illnesses are tested for COVID-19, RSV and flu while hospitalized, infectious disease doctors say.

What types of surveillance are there for H5N1?

said Henry wastewater testing searches for H5 flu in BC

But current wastewater testing makes no distinction between human and animal sources. The tests also do not distinguish between low-pathogenic bird flu and highly pathogenic viruses that can cause many illnesses or deaths, researchers report.

The federal government's wastewater monitoring dashboard for respiratory activity like influenza includes a map of locations across the country submit wastewater samples.

PHAC said provincial and territorial public health authorities must report both “confirmed and probable” H5N1 cases within 24 hours.

What is Canada doing to keep the American version of H5N1 at bay?

Bird flu has affected more than 450 dairy farms in 15 US states since March. The U.S. Centers for Disease Control and Prevention lists 46 human cases of bird flu since April no cases of human-to-human transmission.

The Canadian Food Inspection Agency (CFIA) has also tested milk for signs of H5N1 in dairy cows. No cases of H5N1 have been reported in dairy cattle in Canada.

There is also no evidence of bird flu in commercial milk samples. “Milk and milk products that have been pasteurized are safe to consume,” according to the Public Health Agency of Canada.

As of April 29, CFIA has her export certificate requirements for breeding livestock from the US, such as the certification that lactating cows have tested negative for the influenza A virus.

For poultry, the CFIA has limited the rules since February 11, 2022 import of bird by-products from areas with active outbreaks to try to keep out forms of bird flu that are pathogenic to birds.

The CFIA also requires farmers to report if they suspect that their poultry or livestock has bird flu. The agency says there are currently 28 properties in B.C bird flu infectionsalong with two in Alberta and one in Saskatchewan.