A virulent bird flu epidemic continues to spread across the US, with outbreaks detected at poultry farms in 32 states. More than 28 million chickens and turkeys have died or been destroyed since February, when the first case was detected at a turkey farm in Indiana.
The US Department of Agriculture called the ongoing outbreak of H5N1, a strain of highly pathogenic avian influenza, "a serious concern for our nation's poultry industry" and has approved nearly $263 million to support rapid response efforts.
The current epidemic has seen wholesale egg prices in the Midwest jump 85% in May to $2.20 a dozen. "Breaker" eggs, which are sold in liquid form to commercial bakeries and restaurant chains, have hit $2.58 a pound, up from 86 cents a pound in early March.
Eventually, that will lead to price increases for products that rely on eggs, like cakes, cookies, salad dressing and even mayonnaise.
What is bird flu?
Bird flu is, which spread naturally among waterfowl and can infect wild birds, domestic poultry and other animals, though rarely humans.
There are more than a dozen strains of bird flu, classified as either "low pathogenic" or "highly pathogenic," depending on their ability to spread disease and kill birds.
The strain bombarding the US right now, Eurasian H5N1, is considered highly pathogenic. It infects the respiratory and gastrointestinal tracts and can quickly tear through an entire flock. Symptoms include a lack of appetite, lethargy, swelling and reduced egg production.
The main source of infection is migratory waterfowl, such as ducks and geese.
"They get infected but don't get sick," Denise Derrer, public information director for the Indiana State Board of Animal Health, told CNET. "Then they shed the virus in their droppings or wherever the land."
Where have outbreaks been detected?
The current strain of H5N1 was first reported in Asia and Europe. In the UK, eggs can no longer be labeled free-range because hens have been cooped up for months to avoid infection.
The USDA confirmed the first US case in a wild duck in South Carolina in mid-January. The first case in a commercial farm came just weeks later in a turkey flock in Dubois County, Indiana. Since then, infections have been reported in farms and backyard flocks in at least 32 states, including Colorado, Connecticut, Delaware, Illinois, Idaho, Iowa, Kansas, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nebraska, New Hampshire, North Carolina, North Dakota, New Hampshire, New York, Ohio, Pennsylvania, South Dakota, Texas, Utah, Wisconsin and Wyoming.
As a result, over 28 million egg-laying hens, poultry chickens and turkeys have been or will soon be "depopulated," or killed, with more infections detected nearly every day.
Among the worst incidents:
- In Iowa, the US' top poultry state, HPAI detected in a commercial flock in Buena Vista County resulted in the destruction of 5.3 million egg-laying chickens, the largest culling at any factory farm in the US. Another outbreak in Osceola County resulted in another 5 million birds being killed.
- A single outbreak at a poultry farm in Wisconsin resulted in 2.7 million egg-laying chickens being killed.
- About 1.4 million birds were set to be destroyed in Pennsylvania in mid-April after an outbreak on a Lancaster County farm.
- More than 2 million hens were killed at a farm in northeast Nebraska after the virus was detected in late April
H5N1 has also been reported in wild birds in 34 states, resulting in the deaths of red-tailed hawks, snow geese, horned owls and at least 36 bald eagles. It's believed to have killed hundreds of cormorants and herons at Baker's Lake forest preserve, a birdwatching haven in Barrington, Illinois.
The last major bird flu epidemic
Between December 2014 and June 2015, the first bird flu epidemic in the US led to more than 50 million chickens and turkeys being destroyed in what the USDA called "the largest poultry health disaster in US history."
One in 12 turkeys died from either the virus or being culled, according to Gro Intelligence, along with one in eight egg-laying hens. Eighty percent of the birds -- some 39 million -- were euthanized between mid-April and mid-May 2015 alone, mostly in Midwestern states.
Prices quickly soared as a result: In the first five weeks of the epidemic, wholesale chicken breast prices increased 17% domestically, according to the USDA's Economic Research Service, and remained inflated for years.
The average cost of a dozen eggs rose 60% and exports plummeted sharply as numerous countries imposed import bans on US poultry.
This time, it could be worse
"If you look at the 2015 situation, at this point in the year there are a lot more wild birds now over a much wider area," biochemist Henry Niman, who has been mapping the locations of Eurasian H5N1 cases across the US. told CNET. "There's more outbreaks already. It's going to get much worse than it is now."
Niman says it's highly likely the record number of culled birds in 2015 will be broken this year.
Unlike the earlier epidemic, outbreaks have reached the Atlantic Flyway -- a major north-south migratory corridor that stretches down the Atlantic Coast from Greenland to South America -- and reached birds in the DelMarVa peninsula.
Poultry industry representatives say they're enforcing strict protocols to control the spread of the virus, including limiting foot traffic on farms, avoiding the sharing of equipment, closing up any holes in barns and making sure water and feed are covered and contaminant-free.
But biochemist Niman says it won't be enough.
"This is just a little skirmish -- the major migration season hasn't even hit yet," Niman said. "The farms are gonna be carpet-bombed in a few weeks. I don't think they're gonna be able to control it, even with what they've learned."
How is bird flu affecting poultry and egg prices?
Rising inflation, labor shortages and supply chain issues have already contributed to meat prices rising across the board -- as has the war in Ukraine, a major supplier of grain used to feed livestock.
But the bird flu outbreaks are adding a premium: In early April, the average cost for a dozen large eggs was up 44% from the same time last year, according to the USDA
Between Feb. 18 and May 6, the wholesale price of broiler chickens shot up from $1.25 to $1.69, an increase of more than 33%. The price of pork only rose about 8% in the same period and beef actually dipped 20 cents a pound.
In March, cases of highly pathogenic avian influenza -- and subsequent cullings -- resulted in a 2.5% decrease in egg production, according to the USDA. At the start of the year, the wholesale price for a dozen eggs was $1.60. It's now nearly $3.00 and is expected to keep climbing. (During the 2015 pandemic, the price of eggs peaked at $2.75.)
Turkey production has fallen by some 150 million pounds, the agency said in an April report, with prices for whole frozen turkeys up almost 20% from last year.
"Prices were raised each quarter with the expectation that they will increase throughout the year," the USDA said in its report.
How the outbreaks will ultimately affect prices depends on which kinds of birds are hit hardest -- egg-laying hens, broilers or turkeys, Grady Ferguson, a senior research analyst at Gro Intelligence, told CNET.
Is bird flu dangerous to humans?
Human infection is rare, with fewer than 900 cases reported since 2003, according to the World Health Organization. Most have been among people working directly with infected birds.
Even if an infected chicken wound up at your local supermarket, avian influenza isn't a foodborne disease, so you couldn't contract it from eating contaminated poultry.
To date,. The case, reported on April 29, occurred in someone involved in the culling of infected poultry in Colorado. According to the US Centers for Disease Control and Prevention, the individual reported fatigue for several days and has since recovered after a course of the influenza antiviral drug oseltamivir.
The CDC said the risk to humans is still low. But the longer and larger the wave of H5N1outbreaks, the higher the chances it could mutate into a strain that's more infectious to humans.
US health officials continue to monitor the situation, and the CDC has produced a candidate vaccine virus as a precaution.
The industry is fighting back
There is no treatment for avian influenza in birds, only a containment protocol: Any fowl that may have come in contact with the virus is destroyed. In many cases, growers are forced to kill every bird on their farm, though the federal government typically reimburses them for some of the cost.
"The industry learned a lot of lessons from 2015," Derrer said. "They've improved biosecurity measures to prevent the virus from being introduced into farms and barns."
Birds infected with avian influenza will quit drinking water and become lethargic.
"That's the first sign that there's something wrong," Derrer added. "Farms can move faster now and test right away. Even in the middle of the night."
Tyson, which processes a reported 47 million chickens a week nationwide, did not return a request for comment.
A representative from Perdue Farms said the company is closely monitoring the situation, updating farmers daily about potential outbreaks and sending "company flock advisors" to visit farms and review biosecurity procedures.
The industry "remains on high alert," according to Tom Super of the National Chicken Council.
"Detailed plans are in place to control spreading among flocks and eliminate the virus completely," Super said in a statement. Farmworkers are wearing dedicated footwear in the barns, carefully disinfecting delivery trucks and sealing up holes where vermin might introduce the virus into an indoor population.
Federal officials have been testing wild birds, which acts as an "early warning system" for outbreaks among commercial flocks, according to the USDA. If an infection is detected in a farm, a six-mile "exclusion zone" is typically placed around the area, with shipments halted and birds tested daily.
The role of modern farming
As good as biosecurity measures may be, critics of the industry say factory farming -- which sees tens of thousands of birds crammed into huge sheds -- has created an environment where avian influenza can thrive.
"If you were trying to design a system to optimally spread disease, you couldn't design a better one than modern poultry farming," said Andrew deCoriolis, executive director of the sustainable-agriculture nonprofit Farm Forward.
A single farm can have anywhere from one to ten barns in a field, with 500,000 or more birds on the ground.
"The threat of housing animals by the tens of thousands is a huge risk. It gives viruses a huge population of hosts to prey on -- to mutate and to thrive," deCoriolis told CNET.
Aside from the farms themselves, he added, the industry has spent decades modifying the genetics of chickens and turkeys to get them as big as possible as fast as possible -- at the expense of their immune systems.
"They all have the same immune system -- or lack of an immune system," Dr. Gail Hansen, a public health veterinarian and former state epidemiologist for Kansas, told The New York Times. "So once a virus gets inside a barn, it's going to spread like wildfire."
Breeding genetically uniform birds is efficient from a profit perspective, deCoriolis said, "but it's incredibly dangerous."