In the farm belt of the upper Midwest, farmworkers are shoveling millions of chickens and turkeys into incinerators, burying them in mass graves, or dumping some into landfills as a bird flu epidemic wends its way through the region.
Losses have skyrocketed to nearly 40 million birds since the virus first reached US shores in December, according to the US Department of Agriculture's Animal and Plant Health Inspection Service. Those losses have mounted as the bug sweeps through large commercial growers in states like Iowa, where one chicken farm had to have 5.7 million birds destroyed.
"It's a brand-new type of avian influenza virus, and it seems to spread much more easily than other types," Iowa State University veterinarian and microbiologist Jim Roth told VICE News. The virus is believed to have originated in Asia and mingled with another strain after reaching the Pacific shores of North America.
"When it started on the West Coast, it was mostly in wild birds," said Roth, who leads the Center for Food Security and Public Health at Iowa State. It then spread to small backyard chicken flocks, then began decimating big farms in the Midwest.
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It's only the fourth bird flu outbreak to hit the United States, and the first highly virulent one to hit the Midwest. Although big farms take extensive precautions to keep disease from spreading, Roth said, "Now we have all of these really large operations and we're finding out how vulnerable they are."
"It's an outbreak unlike any we've had before, because of the number of birds affected," he said. "It's bigger, and it's not done yet."
Scientists are still trying to determine how it's spread — perhaps by air, perhaps in feed, perhaps on the boots or vehicles of farm workers.
"There's a need for very strict biosecurity," he said.
Workers on contaminated premises are wearing masks, Tyvek coveralls and gloves, changing clothes, and showering to avoid spreading the illness.
The number of new cases has dropped sharply in the past few weeks, with only about a third as many birds being put down in the past week, University of Illinois agricultural economist John Newton told VICE News. No cases have been reported in humans, and the US Centers for Disease Control says there's little risk of that happening.
But it's likely to have a big economic impact: The outbreak has driven up the prices of eggs by about a dime a dozen and prompted some US trading partners to ban the sales of American-raised chicken, Newton said.
In Minnesota, where turkey farms make up most of the losses, the University of Minnesota's extension service estimated the losses at $309 million by early May. The impact is rippling outward from the farms to trucking companies and processing plants, and the estimate could more than double if the outbreak continues, the service concluded.
Even as huge as the numbers are, they're a small fraction of the more than 8 billion-plus chickens that are slaughtered every year.
"Some people interpret this as 'Hey, it's a not a big deal. It's a very small fraction of what we're consuming.' Other people say this is potentially enormous," said Todd Kuethe, who co-authored a recent article on the outbreak with Newton. "But everybody's in agreement that for the farms where this does occur, it's absolutely catastrophic. They have to liquidate their entire inventory."
For critics of industrial farming like Michael Greger, it was only a matter of time before those chickens came home to roost.
"If you were trying to create conditions to ratchet up the virulence of this virus, you would pack tens of thousands or hundreds of thousands birds into a facility with no windows," said Greger, a physician and director of public health and animal agriculture at the Humane Society of the United States. "Keep it damp, keep it dark, and then you have massive numbers of hosts to generate a huge quantity of viruses."
Airborne microbes often struggle to remain alive in the open air before finding a new host, Greger told VICE News. "But when the next beak is inches away in some of these industrial confinement systems, there's kind of no limit to how virulent the virus can get," he said.
Though there's no sign this virus will jump to humans, industrialized farming makes it more likely that a future strain might, he said.
"Migratory birds can be thought of as providing the fuse, but these kind of industrial facilities are the explosive," Greger said. The only long-term solution, he argues, is to defuse that risk by getting rid of the "factory-farm powder keg."
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But Roth said large chicken operations — particularly those that house egg-laying hens — "have very, very good biosecurity — we thought." But somehow the virus is getting around those measures, "which we didn't anticipate."
"Those birds are very healthy. They have excellent nutrition — they have to, to produce the number of eggs they do," Roth told VICE News. "But once it gets into a building like that, where you've got 200,000 in one building, it explodes, because there's so many birds and it's so highly lethal."
Farmers have a natural ally in sunlight, which viruses don't tolerate well. As summer brings warm, bright days, the outbreak is likely to recede, Roth said. But he said authorities around the country need to be ready for a possible resurgence in the fall.
"Hopefully it won't come back, but we need to be prepared in case it does," he said. "And the whole US needs to be prepared in case it does."
Follow Matt Smith on Twitter: @mattsmithatl