WEDNESDAY, Nov. 13, 2024 (HealthDay News) — Amid an ongoing outbreak of bird flu in American dairy herds and poultry flocks, Canadian officials have announced that a teen in British Columbia has been hospitalized in critical condition with what is believed to be bird flu.

It’s not clear how the teenager picked up the H5N1 virus because the patient is not known to have any contact with infected animals, officials noted. They added that this is the first human case of the virus reported in both the province and Canada.

“The positive test for H5 was performed at the BC Centre for Disease Control’s Public-Health Laboratory,” Dr. Bonnie Henry, provincial health officer of British Columbia, said in a statement. “Samples are being sent to the National Microbiology Laboratory in Winnipeg for confirmatory testing.”

“This is a rare event, and while it is the first detected case of H5 in a person in B.C. or in Canada, there have been a small number of human cases in the U.S. and elsewhere, which is why we are conducting a thorough investigation to fully understand the source of exposure here in B.C,” Henry added.

Testing has been performed on about three dozen people who were in contact with the teen, but none show evidence of infection, Henry said.

Meanwhile, a case of bird flu has been detected for the first time in a pig in the United States as officials scramble to contain the spread of the virus there.

“The U.S. Department of Agriculture [USDA] and Oregon state veterinary officials are investigating positive cases of H5N1 in a backyard farming operation in Oregon that has a mix of poultry and livestock, including swine,” the USDA said late last month in a news release announcing the case.

“The Oregon Department of Agriculture announced on Friday, Oct. 25, that poultry on this farm represented the first H5N1 detection in Crook County, Oregon,” the agency added. “On Tuesday, Oct. 29, the USDA National Veterinary Services Laboratories also confirmed one of the farm’s five pigs to be infected with H5N1, marking the first detection of H5N1 in swine in the United States.”

Although the pig did not show symptoms of infection, all five swine on the farm were tested for H5N1. All five were euthanized for further testing, according to the USDA. Results were negative for two of the pigs, while one of the other two pigs tested positive for bird flu, the USDA reported in an update.

The farm has been quarantined, but since it wasn’t a commercial farm, “there is no concern about the safety of the nation’s pork supply as a result of this finding,” the agency added.

Scientists have been worried that H5N1 might spread to pigs, which are considered a “mixing bowl” species for flu viruses because they carry the same kind of receptors on cells in their lungs as humans and birds.

In fact, the 2009 swine flu pandemic is believed to have been sparked by a virus that mutated in pigs in Mexico before it jumped to people.

Health officials also reported recently that a second person in Missouri who wasn’t exposed to either poultry or dairy cows has been infected with bird flu.

This person shared a home with a patient who was first hospitalized with bird flu in August, but antibody tests have since shown that symptomatic health care workers who cared for the patient were not infected with the H5N1 virus, the U.S. Centers for Disease Control and Prevention said in a bird flu update.

However, there was some reassuring news: There was no evidence that H5N1 had passed person-to-person because the fact that “these two individuals had identical symptom onset dates support a single common exposure to bird flu rather than person-to-person spread within the household,” the CDC noted.

“To date, human-to-human spread of H5 bird flu has not been identified in the United States,” the agency added. “CDC believes the immediate risk to the general public from H5N1 bird flu remains low, but people with exposure to infected animals are at higher risk of infection.”

Indeed, the number of human cases of bird flu connected to livestock is rising rapidly in the United States. In total, 46 people have been infected with bird flu in the United States this year, CDC data show.

The latest cases fuel growing concern among public health experts that the ongoing bird flu outbreak will eventually trigger human-to-human transmission of the virus.

Across the country, more than 492 dairy herds in 15 states have been infected since the outbreak in dairy cows was first confirmed in March. Avian influenza has been spreading in wild and domestic birds in the United States for several years.

“We should be very concerned at this point,” Dr. James Lawler, co-director of the University of Nebraska’s Global Center for Health Security, told the New York Times. “Nobody should be hitting the panic button yet, but we should really be devoting a lot of resources into figuring out what’s going on.”

More information

The CDC has more on bird flu.

SOURCES: British Columbia Ministry of Health, news release, Nov. 9, 2024; U.S. Centers for Disease Control and Prevention, news releases, Oct. 30, 2024; Oct. 24, 2024, Oct. 18, 2024; Oct. 3, 2024; New York Times

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