For months, federal authorities have been tracking a highly contagious animal disease that has been inching closer to Pennsylvania.
Late Friday, the state Game Commission confirmed that a strain of highly pathogenic avian influenza (HPAI), commonly called “bird flu,” was detected in a bald eagle found dead in Chester County, west of Philadelphia.
The discovery marks the first time this particular variant has been detected in Pennsylvania since the virus was detected in North America in December 2021. During previous outbreaks in the United States, the disease caused the deaths of thousands of wild and domesticated birds.
The Chester County eagle may not be HPAI’s only Pennsylvania victim. The Game Commission said necropsy results are pending for the remains of five waterfowl recovered 90 miles northeast of Pittsburgh in Kahle Lake, on the border of Venango and Clarion counties. Four hooded mergansers were found dead, and another was euthanized after exhibiting neurological symptoms similar to birds dying from avian flu.
The risk to humans is undetermined. Three HPAI variants are known to have infected wildlife and commercial poultry in North America. Those strains, including the H5 variant that has entered Pennsylvania, cannot be contracted by humans, according to a website description of avian flu published by the Centers for Disease Control and Prevention.
“To date, no human infections with HPAI H5 viruses have been identified in the United States,” said the CDC overview. It referred to the disease as “an animal health issue.”
However, earlier this month, as avian flu was being tracked among commercial and backyard poultry in 13 states, and in wild birds in 14 states, CDC released an alert that subtly upgraded the risk to humans.
“Based on available epidemiologic and virologic information about these viruses, CDC believes that the risk to the general public’s health from current H5N1 bird flu viruses is low. However some people may have job-related or recreational exposures to birds that put them at higher risk of infection.”
The statement suggested that humans who have been infected with bird flu likely were in close contact with infected birds without taking recommended precautions, such as wearing protective equipment.
“Sporadic human infections with current H5N1 bird flu viruses would not be surprising,” said the CDC statement, “especially among people with exposures who may not be taking recommended precautions.”
The Game Commission said the monitoring and analysis of wild and domestic birds throughout the commonwealth was being conducted by its biologists, the Pennsylvania Department of Agriculture, U.S. Department of Agriculture, the Wildlife Futures Program at the University of Pennsylvania School of Veterinary Medicine and the Pennsylvania Animal Diagnostic Laboratory System. USDA, the organization that is posting avian flu updates, said in a statement the United States has the strongest avian influenza surveillance program in the world.
Avian influenza is naturally occurring and ever-present among wild birds, according to a Game Commission statement. Symptoms in the wild are nonspecific but may include neurologic dysfunction such as circling and difficulty flying.
“Preventing or controlling HPAI in wild populations is not feasible,” it said.
Birds may carry the disease without showing signs of illness, acting as reservoirs for the virus. Birds that appear healthy can spread the virus through bodily fluids, and it can cause sickness or death among waterfowl, avian scavengers, ruffed grouse, wild turkeys and raptors.
Thousands of Pennsylvania hunters are expected to be in physical contact with turkeys during the monthlong spring gobbler season, which begins April 30. Across the state, it’s hatching time for bald eagles. Last week on livestreaming cameras, three eaglets were seen pecking through their eggs at a nesting site in Hays, and two were hatched in a nest at the U.S. Steel Irvin works in West Mifflin.
Rachel Handel, spokeswoman for the Audubon Society of Western Pennsylvania, said bald eagles frequently eat other birds, and if their prey is infected with avian flu it could potentially spread to the eagle.
“While a bald eagle was impacted by the virus in Eastern Pennsylvania, it doesn’t mean that the Pittsburgh region’s bald eagles will fall victim to the illness,” she said. “Although bald eagles can get the disease, they are not necessarily any more susceptible to it than other birds.”
Because of the bald eagle’s national status and conservation recovery, she said, “diseases and other problems like lead toxicity are often detected in bald eagles because when a dead eagle is found, the authorities often try to determine the cause of death.”
The Pennsylvania Department of Agriculture has not commented on the arrival of avian influenza, or its threat to the state’s $7.1 billion poultry industry. But a spokeswoman said the disease has been on the department’s radar.
“I can tell you the response plan has been in place for several years and is regularly reviewed and updated,” said Shannon Powers, press secretary for the state Department of Agriculture.
In February, Russell Redding, Pennsylvania agriculture secretary, called the HPAI threat “imminent” and said commercial producers and backyard flock owners should take strategic measures to protect their birds, operations and personal health.
The most important thing for poultry owners to do, he said, is beef up their biosecurity. Keep other birds away from the flock, stay as far from poultry pens as possible, wear personal protection when in contact with the birds and post signs alerting others of the possible biosecurity risk.
John Hayes: jhayes@post-gazette.com.
First Published: March 29, 2022, 10:00 a.m.
Updated: March 29, 2022, 10:13 a.m.
