Producers have killed more than 37 million chickens and other poultry species to contain an outbreak of highly contagious avian influenza virus that first reached commercial poultry farms in February, according to the most recent U.S. Department of Agriculture data.
And, in late April, the avian flu was detected in a human for the first time since the outbreak began.
The man, who is incarcerated at a Colorado state prison, contracted the virus while he was slaughtering infected chickens at a commercial poultry farm while on work release, according to the Colorado Department of Public Health and Environment.
The man was largely asymptomatic and it’s possible the virus was detected in his nose without causing an infection, Colorado officials said.
In a statement to Investigate Midwest, the Centers for Disease Control and Prevention said that the single case of avian flu detected in a human doesn’t change the risk level for the general public, which is low.
The current strain of bird flu emerged in Europe in fall of 2020 and became the dominant virus strain worldwide by the end of 2021, the CDC said in a statement.
In January, the USDA detected the Eurasian strain of avian flu in a wild bird for the first time since 2016. The agency announced that the virus reached a commercial flock in Indiana on February 9.
“So far, current H5N1 bird flu viruses lack changes seen in the past that have been associated with viruses spreading easily among poultry, infecting people more easily, and causing severe illness in people,” the CDC wrote. “There is little information about the spectrum of illness that could result from human infections with current H5N1 bird flu viruses.”
The virus is transmitted through the manure and body fluids of infected poultry. That means poultry workers are at a higher risk than the general public for contacting the avian flu, though the overall risk is still low even for poultry workers, said Jeff Bender, director of the Upper Midwest Agricultural Safety and Health Center.
“We need to be monitoring though, because we have seen types of influenza viruses that actually can be lethal,” Bender said. “It's important to have mechanisms in place to not only try to control the disease so that we don't get spread, but also mechanisms to be able to follow up with those most at-risk. And those most at-risk are those that are actually in direct contact with active birds.”
Bender added that the detection of avian flu in an asymptomatic poultry worker is a sign that monitoring and testing procedures are working.
A significant percentage of poultry workers are immigrants, or speak languages other than English, posing communication challenges for public health officials, Bender said.
“If you think back to the COVID cases back in May of 2020, and the impact especially on the immigrant workforce, we need to think about innovative resources and ways to reach that population to really explain the disease as well as provide them appropriate protective measures,” Bender said.
People working with poultry should avoid direct contact with birds as much as possible, and wash their hands with soap and water after touching birds or potentially contaminated surfaces, the CDC said. The CDC also recommends using gloves, masks and eye protections when working with infected birds.
Because the virus is also infecting wild birds, all people should avoid coming into contact with dead birds and bird feces outside, and should wash their hands if contact occurs, the CDC said.
Flu hits egg-laying hens and Iowa the hardest
More than a third of the cases have been reported in Iowa, resulting in a loss of more than 13 million birds. And, according to data provided to Investigate Midwest by the National Chicken Council, egg-laying hens account for nearly 80% of affected birds.
Cases have also been reported in backyard chickens and wild birds.
A representative from Perdue Farms, one of the country’s largest chicken companies, said the company had outbreaks at two turkey farms in Indiana. None of the company’s other poultry facilities have been affected.
“We know biosecurity remains the best defense to ensure the safety and welfare of the birds in our care, including the spread of AI and other poultry-related diseases,” the spokesperson said in a statement. “We continue to work with our farm partners to ensure we remain mutually vigilant in adhering to heightened biosecurity best practices.”
Representatives of three other major American chicken companies — Tyson Foods, Sanderson Farms and Pilgrim’s Pride — did not respond to requests for comment.
The USDA’s Animal and Plant Health Inspection Service — the division of the USDA responsible for responding to the avian flu — also did not respond to a request for comment.
Because of the highly contagious nature of the virus, all poultry at an impacted facility should be culled within 24 to 48 hours of a presumptive positive case of avian flu in order to minimize the risk of disease spread, according to the American Veterinary Association’s guidelines.
“I want to (assure) people that the risk to them is extremely low, and that it is safe to eat poultry products,” said Dr. Ashley Peterson, senior vice president of scientific and regulatory affairs at the National Chicken Council in a statement to Investigate Midwest.
The CDC has also reiterated that properly prepared poultry and eggs remain safe to eat.
Top image: Pasture-raised Red Sexlink Hens on a farm in Bryantown, Maryland. photo: USDA/FPAC photo by Preston Keres