A B.C. teen has a suspected case of H5N1 avian flu 91裸聊视频� the first known human to acquire the virus in Canada.

The provincial government said on the weekend that B.C.91裸聊视频檚 chief veterinarian and public health teams are still investigating the source of exposure, but that it91裸聊视频檚 91裸聊视频渧ery likely91裸聊视频� an animal or bird.

Human-to-human transmission is very rare, but as cases among animals rise, many experts are worried the virus could develop that ability.

The teen was being treated at BC Children91裸聊视频檚 Hospital on Saturday. The provincial health officer said there were no updates on the patient Monday.

91裸聊视频淚91裸聊视频檓 very concerned, obviously, for the young person who was infected,91裸聊视频� said Dr. Matthew Miller, director of the Michael G. DeGroote Institute for Infectious Disease Research at McMaster University in Hamilton, Ont.

Miller, who is also the co-director of the Canadian Pandemic Preparedness Hub, said there have been several people infected with H5N1 in the U.S.,and almost all were livestock workers.

In an email to The Canadian Press on Monday afternoon, the Public Health Agency of Canada said 91裸聊视频渂ased on current evidence in Canada, the risk to the general public remains low at this time.91裸聊视频�

WHAT IS H5N1?

H5N1 is a subtype of influenza A virus that has mainly affected birds, so it91裸聊视频檚 also called 91裸聊视频渂ird flu91裸聊视频� or 91裸聊视频渁vian flu.91裸聊视频� The H5N1 flu that has been circulating widely among birds and cattle this year is one of the avian flu strains known as Highly Pathogenic Avian Influenza (HPAI) because it causes severe illness in birds, including poultry.

According to the World Health Organization, H5N1 has been circulating widely among wild birds and poultry for more than two decades. The WHO became increasingly concerned and called for more disease surveillance in Feb. 2023 after worldwide reports of the virus spilling over into mammals.

HOW COMMON IS INFECTION IN HUMANS?

H5N1 infections in humans are rare and 91裸聊视频減rimarily acquired through direct contact with infected poultry or contaminated environments,91裸聊视频� the WHO91裸聊视频檚 website says.

Prior to the teen in B.C., Canada had one human case of H5N1 in 2014 and it was 91裸聊视频渢ravel-related,91裸聊视频� according to the Public Health Agency of Canada.

As of Nov. 8, there have been 46 confirmed human cases of H5N1 in the U.S. this year, the Centers for Disease Control and Prevention says. There is an ongoing outbreak among dairy cattle, 91裸聊视频渟poradic91裸聊视频� outbreaks in poultry farms and 91裸聊视频渨idespread91裸聊视频� cases in wild birds, the CDC website says.

There has been no sign of human-to-human transmission in any of the U.S. cases.

But infectious disease and public health experts are worried that the more H5N1 spreads between different types of animals, the bigger the chance it can mutateand spread more easily between humans.

WHAT ARE THE SYMPTOMS OF H5N1?

Although H5N1 causes symptoms similar to seasonal flu, such as cough, fever, shortness of breath, headache, muscle pain, sore throat, runny nose and fatigue, the strain also has key features that can cause other symptoms.

Unlike seasonal flu, most of the people infected in the U.S. have had conjunctivitis, or 91裸聊视频減ink-eye,91裸聊视频� said Miller.

One reason for that is likely that many have been dairy cattle workers.

91裸聊视频淎t these milking operations, it91裸聊视频檚 easy to get contamination on your hands and rub your eyes. We touch our face like all the time without even knowing it,91裸聊视频� he said.

91裸聊视频淎lso, those operations can produce droplets or aerosols, both during milking and during cleaning that can get into the eye relatively easily.91裸聊视频�

But the other reason for the conjunctivitis seen in H5N1 cases is that the strain binds to receptors in the eye, Miller said.

While seasonal flu binds to receptors in the upper respiratory tract, H5N1 also binds to receptors in the lower respiratory tract, he said.

91裸聊视频淭hat91裸聊视频檚 a concern 91裸聊视频� because if the virus makes its way down there, those lower respiratory infections tend to be a lot more severe. They tend to lead to more severe outcomes, like pneumonias for example, that can cause respiratory distress,91裸聊视频� Miller said.

WILL THE FLU VACCINE PROTECT AGAINST H5N1?

We don91裸聊视频檛 know 91裸聊视频渨ith any degree of certainty,91裸聊视频� whether the seasonal flu vaccine could help prevent infection with H5N1, said Miller.

Although there91裸聊视频檚 no data yet, it91裸聊视频檚 quite possible that it could help prevent more severe disease once a person is infected, he said.

That91裸聊视频檚 because the seasonal flu vaccine contains a component of H1N1 virus, which 91裸聊视频渋s relatively closely related to H5N1.91裸聊视频�

91裸聊视频淪o the immunity that might help protect people against H5N1 is almost certainly conferred by either prior infection with or prior vaccination against H1N1 viruses that circulate in people,91裸聊视频� Miller said.

HOW ELSE CAN I PROTECT MYSELF?

The Public Health Agency of Canada said as a general precaution, people shouldn91裸聊视频檛 handle live or dead wild birds or other wild animals, and keep pets away from sick or dead animals.

Those who work with animals or in animal-contaminated places should take personal protective measures, the agency said.