Bird flu infections appear to be on the rise, alerting the poultry industry and raising concerns about the pandemic potential of the virus, health organizations say.
According to the U.S. Centers for Disease Control and Prevention, since 2014 — when the first bird flu infection in a person was detected in China — 51 infections of the H5N6 subtype of avian influenza have been reported, including 21 during 2021 alone as of Oct. 29.
"Most of the cases of influenza A(H5N6) reported in China during 2021 have had exposure to birds prior to illness onset," the CDC wrote in a report published on Nov. 1.
In Europe, Belgium’s government recently put the country on high alert for bird flu following the detection of the virus across the continent, Reuters reported Monday.
"I have to make sure that we prevent the contamination of our poultry with avian flu at all costs," Belgium’s agriculture minister David Clarinval said on Twitter.
Earlier this month, poultry farmers in France were ordered to keep flocks indoors following more than 100 outbreaks of bird flu in recent months, according to Reuters.
The World Organization for Animal Health (OIE) told Reuters that an outbreak of another strain of bird flu, H5N1, infected a flock of 7,000 birds.
According to the CDC, avian influenza — or bird flu — typically impacts aquatic birds worldwide and can also infect domestic poultry. Like COVID-19, there are several strains of the virus that have been reported globally.
While bird flu viruses don’t normally infect humans, there have been reports of sporadic human infections.
"This is concerning because of the possibility that bird flu viruses could change and gain the ability to spread easily between people, with the potential to cause a flu pandemic; therefore, continued monitoring for human infections of bird flu and person-to-person spread is extremely important for public health," the CDC explains.
In June, a man in eastern China contracted what might have been the world’s first human case of the H10N3 strain of bird flu. At the time, the government assured the public that the risk of large-scale spread was low.
The 41-year-old man in Jiangsu province, northwest of Shanghai, was hospitalized April 28 and was reported to be in stable condition, the National Health Commission said on its website.
No human case of H10N3 had been previously reported elsewhere, the commission said.
"This infection is an accidental cross-species transmission," its statement said. "The risk of large-scale transmission is low."
The news of bird flu outbreaks come amid heightened awareness of the threat of emerging diseases as the COVID-19 pandemic continues to claim lives around the world.
But unlike with coronaviruses, there are global influenza surveillance systems that watch for human cases of bird flu, since a strain named H5N1 cropped up in the late 1990s in Hong Kong’s crowded live-poultry markets.
Between 2013 and 2017, another bird flu named H7N9 infected more than 1,500 people in China through close contact with infected chickens.
With that history, authorities aren’t surprised to see occasional human cases of various bird flu strains and they monitor closely for any signs one is spreading between people.
This story was reported from Los Angeles. The Associated Press contributed.