A highly contagious virus that began with widespread outbreaks among poultry in factory farms took little time to cross over to wild bird species and then trickle into mammals.
More commonly known as the bird flu, the highly pathogenic avian influenza continues to leave its impact on livestock and wildlife around the world, barreling its way through a growing number of species each day. Last week, a Texas laboratory confirmed the state’s first mammal to test positive for the H5N1 bird flu strain.
According to the Texas Parks and Wildlife Department, the report came after a Carson County resident found themselves in the pathway of a disoriented striped skunk which approached them with a seemingly more comfortable disposition than typically seen among wildlife.
“It’s been found in other states, and all the animals have been showing neurological signs. They’re uncoordinated and just look drunk,” TPWD Veterinarian Dr. Sara Wyckoff said. “This skunk was exhibiting all of those symptoms and walking up to people.”
Closely matching the behavioral symptoms of a mammal with rabies, the agency tested the striped skunk for both rabies and avian flu and discovered the latter as positive.
Though there are no other confirmed cases in the state, Wyckoff said it’s “definitely a good assumption” that other wildlife species in proximity to the skunk — which was found just on the outskirts of Amarillo — are infected.
A wildlife epidemic
Though the discovery of the virus tracks back to 1996 via infected waterfowl in Southern China, the avian flu’s reemergence and most recent surge was identified in Europe in 2020, according to the Centers for Disease Control and Prevention.
In the existing strain’s earliest days, the virus primarily took over large-scale factory farms and the occasional backyard chicken flock, killing more than 59 million poultry — the industry’s largest hit since another major outbreak took the lives of more than 50 million birds in 2014-15 — and 6,400 wild birds since its arrival to the U.S. last January.
According to CDC data, this includes 200 wild birds and five commercial flocks in Texas.
Wildlife officials have also detected the virus in 16 wildlife mammal species across the nation, including the American black bear, bobcat, bottlenose dolphin, coyote, fisher, grey seal, grizzly bear, harbor seal, kodiak bear, mountain lion, North American river otter, raccoon, red fox, skunk, striped skunk, and Virginia opossum.
The virus has also spread to two endangered species in captivity: an Amur leopard at the Rosamond Gifford Zoo in Syracuse, New York, and an Amur tiger at the Riverside Discovery Center in Scottsbluff, Nebraska.
The local NBC Station in Scottsbluff reported in December that the tiger’s infection was likely linked to an outbreak that resulted in the death of a grizzly bear and four big cats — two tigers and two mountain lions — though the zoo confirmed only one of each species.
There have been no reported cases among domesticated dogs and cats, and Wyckoff said it remains very unlikely.
“Mammals can’t pass it to each other, but of course, if an animal does eat an infected mammal carcass, that probability increases,” Wyckoff said.
Minimal risk to humans
Coming on the heels of the COVID-19 pandemic that’s shaken our world for more than three years now, many individuals have become wary of the possibility for another epidemic passed from animal to human, especially as experts recently began to cite raccoon dogs as the coronavirus’ likely origin.
The avian flu, like the coronavirus, is considered a zoonotic, meaning it has the potential to spread to humans, but experts say that’s not likely, and only one human case has been reported in the U.S.
“Technically, this strain is (possible for humans), but there has been little risk to people,” Wycoff confirmed.
According to the CDC’s announcement in April, the single positive case came from a Colorado resident who was a poultry worker with direct exposure to the culling of chickens that were presumptively infected with avian flu. The only symptom the patient reported, according to the CDC, was fatigue which he recovered from within a few days.
Still, experts recommend humans don’t put themselves in close contact with a potentially infected animal.
“You definitely shouldn’t approach the area or touch it. You still want to practice caution and don’t want to put yourself at a rabies health risk,” Wyckoff said. “Contact your local game warden or biologist (if you come across an infected animal).”