By Traci Badalucco and Christina Bucciere
Millions of avian flu-infected hens are expected to be euthanized on a major egg-producing farm in northwest Iowa with the help of the state.
Nearly 3 million hens will be euthanized with carbon dioxide on Sunrise Farms’ facility, said Dustin VandeHoef, communications director at the Iowa Department of Agriculture.
The Sonstegard Foods Company, which owns Sunrise Farms in Osceola County, said in a press release, “In accordance with our policy, we are working with the United States Department of Agriculture, state officials and the industry to take whatever steps are necessary to prevent the further spread of the disease.”
VandeHoef said the hens will be euthanized over several days in a set of houses on the facility. The state department is still coordinating with the USDA, Sunrise owners and the Iowa Department of Natural Resources to determine the best way to dispose of the carcasses.
“There have been talks of rendering, composting or burial, so it could be a combination,” VandeHouf said.
Kevin Baskins, spokesman for the Iowa Department of Natural Resources, said while euthanasia methods are up to Sunrise Farms, disposal methods are subject to state approval.
“Our concern is that it minimizes the potential to spread the disease and doesn’t put our national resources in jeopardy,” Baskins said, adding, “We kind of have a double whammy here. Obviously you want to make the right decision, but it needs to be made relatively quickly.”
Rendering is “a process for handling dead animals,” Baskins said. “Usually you’re trying to come up with some sort of value-added material at the end.”
Rendering converts dead animal tissue into a variety of safe and salvageable products for industrial goods.
Baskins said Sunrise Farms had an estimated 3.8 million birds and one million have died naturally from the disease.
Choosing a burial site is also a concern, said Baskins, and preventive measures must be taken to avoid water contamination, including placing a clay material under the carcasses, but it doesn’t pose any threats over the long term.
“When you think about it, birds, like us, are made up of phosphorus and nitrogen, and it will just decompose,” Baskins said. “Obviously there could be some of that virus in the soil, but that will die out as well.”
VandeHouf said workers are wearing protective gear including rain boots and coveralls to prevent spread, and the facility will be disinfected after the birds are removed.
The capacity for egg-laying hens at Sunrise Farms is 5.3 million, though the current population was an estimated 3.8 million. The number of infected hens is still unknown, but all 3.8 million will be euthanized.
The Iowa Department of Agriculture and Land Stewardship placed Sunrise Farms under quarantine until further notice.
Nearly 20 percent of the eggs consumed in the U.S. comes from Iowa, according to NPR.
Avian influenza or “bird flu” is a virus that infects domestic poultry. The H5N2 strain is affecting many other states, including Minnesota and Wisconsin, South Dakota and Kansas.
Experts believe the H5N2 strain is being spread by the droppings of wild birds, such as geese or ducks, migrating across the U.S., Dr. Kyoung-Jin Yoon, a veterinarian and professor at Iowa State University said.
Humans can unknowingly spread the droppings by tracking them through farms or trucks and cars whose wheels pick it up.
The virus may even be an aerosol from the droppings as the birds migrate, and in the warmer months when farmers open cage windows for better circulation, the birds could be more exposed, Yoon said.
The virus can cause low energy, diarrhea, sneezing, runny nose, purple discoloration of the legs, decreased egg production and sudden death in infected birds, according to the USDA.
The birds can die within 48-72 hours after infection, Yoon said.
Because of the rapid spread, depopulation of infected birds is necessary to prevent further spread of the virus “and is a way to rescue the diseased animals from their misery,” Yoon said.
There have been no reported cases of human avian influenza from the current outbreak in the U.S. so far, and the risk of human contraction is low, Yoon said.
“Circumstantial evidence indicates this virus is not high risk for humans at this point and there are other things in place around how we handle the infected flock and so on that further reduces the chance that it can transmit from the bird to the humans,” Yoon said.
The likelihood of bird-to-human transmission of bird flu strains depends on how well humans are protected against them, said David Meyerholz, a veterinary pathologist at the University of Iowa.
“Some of the the newer influenzas like this one, some of these have background immunity in our system from other viruses we’ve been exposed to that makes it so it’s not so transmissible,” Meyerholz said. “Each year we get vaccinated for several different strains they anticipate for the upcoming season and, over the years, we have some cross immunity to these newer viruses.”
But because viruses are constantly mutating, human immune systems must constantly adapt. When viruses undergo low-level mutations, known as antigenic drift, they are less transmissible, but when they go through major mutations, known as antigenic shift, they can affect humans.
“Major shifts of genetic material to make the virus into a new bug haven’t seen before,” he said.
The H5N2 strain, so far, has proven to be non-transmissible, Meyerholz said.
And because of the preventive measures taken to contain the virus, it is unlikely to contaminate the food supply. Even if it did, routine hygiene and handling of poultry would kill the virus when it’s cooked, Meyerholz said.
Iowa’s egg production industry is highly concentrated, with only 40 farms supplying 97 percent of the eggs, making it less likely the outbreak will affect prices if contained, said David Swenson, an Iowa State University economist.
“If it moves from large farm to large farm, it can have a rapid impact on the supply of hens or eggs, versus if it moves from small farm to small farm, their share is so small it wouldn’t affect prices very much,” Swenson said. “It would affect the farms but not the prices.”
The FDA says the chances of infected poultry or eggs moving into food chain is extremely low because of safeguards such as federal inspection program and the fact that infected hens generally stop laying eggs.
Swenson said because most of Iowa’s egg production is sold for Midwest consumption, the impact of the supply reduction will likely remain regional, unless consumers stop buying eggs.
“You and I can hoard all kinds of things, but you can’t hoard eggs. They have a shelf life. You really count on a continuous supply of this commodity and if the supply goes down we have to seek some of kind of substitutes,” Swenson said.