From Wyoming to Maine, outbreaks of highly contagious bird flu have spread through farms and backyard flocks in the United States this year, prompting millions of chickens and turkeys to be culled.
Iowa has been particularly hard hit, with disasters declared in some counties and the state canceling live bird shows in an order that could affect the popular state fair.
Here’s what we know about bird flu.
What is bird flu?
Avian influenza, commonly known as bird flu, is a highly contagious and deadly virus that can prey on chickens, turkeys, and wild birds, including ducks and geese. It is spread through nasal secretions, saliva and fecal droppings, which experts say makes it difficult to contain.
Symptoms of the virus include a sudden increase in herd mortality, reduced egg production, and reduced feed and water consumption.
Eurasian H5N1 virus is closely related to an Asian strain that has infected hundreds of people since 2003, most of whom worked with infected poultry. Its spread in the United States is not unexpected, as outbreaks have been previously reported in Asia, the Middle East and Europe.
Should a person be concerned about injury?
The risks to humans are very low, said Ron Keane, a faculty member and extension specialist at the University of Wisconsin in the Department of Animal and Dairy Sciences in Madison.
“It is not impossible for humans to be infected with this virus, but it is very rare,” Professor Kane said.
The Centers for Disease Control and Prevention said it is monitoring people in the United States who have been exposed to infected poultry and other birds. So far, no cases of H5N1 infection have been found among them, the Centers for Disease Control and Prevention said.
Is it safe to eat poultry and eggs?
Yes, according to the USDA, which said that properly prepared and cooked poultry and eggs should not pose a risk to consumers.
The chance of infected poultry entering the food chain is “extremely low,” the agency said. Under federal guidelines, the Food Safety and Inspection Service, part of the USDA, is responsible for inspecting all poultry sold in interstate and foreign trade. Inspectors are required to be present at all times during the slaughter process, according to the service, which indicated that inspectors have unrestricted access to those facilities.
According to the Inspection Service, egg production facilities subject to federal regulations are required to undergo daily inspections once per shift. Government inspection programs, which examine poultry products sold only within the country in which they were produced, are additionally monitored by the USDA
Experts say that due to the mandatory culling of infected flocks, the virus is primarily a health problem for the animal at this time.
However, the USDA recommends cooking poultry to an internal temperature of 165 F to reduce the potential for foodborne illness.
Can I expect to pay more for poultry products?
Egg prices soared when outbreaks swept the United States in 2014 and 2015. Recently, the average price of a great white premium egg has been “sliding sharply up,” according to the March 25 National Retail Report from the USDA. Experts said there may be some shortages of eggs. White and dark chicken meat prices are also up, according to USDA experts, who also warn that turkey prices may also become more volatile.
How is the virus detected?
Testing for bird flu usually involves swabbing the mouths of chickens and turkeys, and the area of their windpipe. Samples are sent to diagnostic laboratories for analysis.
Outbreaks of the disease have been detected in more than a dozen states.
A tracking page maintained by the USDA showed that as of March 31, the highly pathogenic form of bird flu had been detected in 22 states.
According to the agency, the total number of birds in affected flocks – the commercial and backyard type – reached more than 22 million. A spokesman for the US Department of Agriculture confirmed that those birds will need to be euthanized to prevent the spread of the virus.
Two commercial egg production facilities in Iowa, one in Buena Vista County and one in Osceola County, make up the largest infected flocks. The US Department of Agriculture said each is made up of more than 5 million chickens.
The egg producer in Jefferson County, Wisconsin, was the third largest infected flock, with more than 2.7 million chickens.
How do these outbreaks compare with previous outbreaks?
The 2014 and 2015 outbreaks in the United States were blamed for $3 billion in losses to the agricultural sector and were considered the most devastating in the country’s history. Nearly 50 million birds have died, either from the virus or due to having to cull them, most of them in Iowa or Minnesota.
The current footprint of the outbreak, stretching from the Midwest and Plains to northern New England, has raised concerns.
“I think we’re definitely seeing more geographic spread than we saw in 2014-2015,” said Dr. Andrew Bowman, assistant professor at The Ohio State University College of Veterinary Medicine.
What can be done to stop the spread of the virus?
Early last year, the US Department of Agriculture warned of the potential for bird flu outbreaks and stressed tightening “biosecurity” measures to protect flocks of chickens and turkeys.
Biosecurity measures include limiting access to herds and requiring farm workers to practice strict hygiene measures such as wearing disposable shoes and jackets. Experts say sharing farm equipment could contribute to the spread of the virus. So can farm workers who handle wild birds, including when hunting.
“Whether it’s limiting access to the forage and water source, even truck routes, how we try to limit those connections that might spread pathogens between herds, it’s all really important,” Dr. Bowman said. “At this point, everyone who produces poultry should think about how to improve their biological security.”
Is it necessary to kill millions of chickens and turkeys?
Affected birds can experience complete paralysis, swelling around the eyes, and twisting of the head and neck, according to the USDA. The virus is highly contagious, experts say, and there is no choice but to get rid of infected herds.
Methods include spraying chicken and turkey with foam that causes choking. In other cases, carbon dioxide is used to kill birds whose carcasses are often composted or placed in a landfill.
“It’s arguably more humane than letting them die from the virus,” Professor Kane said.