It’s not clear how much the egg industry as a whole has spent on biosecurity in recent years. Some farmers and equipment suppliers said demand increased significantly after a bird flu outbreak in 2015 and again with the current surge, which began in 2022.

“There [were] a lot of firms that said ‘I cannot lose my farm’,” said Keith Bailey, with Hydro-Chem Systems, a manufacturer of truck wash equipment and detergent that’s seen its farmer inquiries at least double each year since 2022.

Preventive steps can be expensive, but failure is worse, farmers say. If one bird tests positive for influenza, the entire flock, sometimes millions of birds, must be culled – killed en masse – to prevent the highly contagious disease from spreading. A federal programme pays farmers for the cost of killed birds, but not for the protective measures they take or the income they lose in the months they’re rebuilding their flock.

“Basically, you’re out of business” when bird flu infects a flock, said Mike Puglisi, whose Delaware egg farm had an outbreak in 2022.

The Animal and Plant Health Inspection Service, which is part of the US Department of Agriculture, has spent about US$1.8 billion ($3.1b) on the current bird flu outbreak, including US$1.2b on payments for culled birds, US$353m for “depopulation, disposal and virus elimination activities,” and about US$82m combating avian influenza in cattle, said spokeswoman Lyndsay Cole.

Jared McCool estimated his Connecticut farm spent about 15 percent of its revenue on biosecurity last year, the most it ever has. His operation – which is raising 25,000 game birds for hunting and eating and has a slaughter-and-processing facility – sanitises animal crates with 180-degree water and organic chemicals, requires workers to wear protective gear and tracks where customers and animals go on the property, among other measures, he said.

There are limits to what the farm can do. McCool’s birds are often outside in big pens that migratory birds can defecate in.

“My no-fly-zone sign doesn’t really get enforced when it comes to migrating geese or ducks,” he joked.

The ramifications of an outbreak can be far-reaching.

Christian Alexandre’s California farm gets most of its income from dairy but had to lay off half of the 12 employees on the egg side of its business in 2022, shortly after its flock of 45,000 hens tested positive for influenza. Letting workers go was harder than six months without egg sales, Alexandre said.

“It’s our employees’ livelihood,” he said.

Of the roughly 160 million bird deaths from avian influenza since 2022, almost 30 million have occurred just in the first six weeks of this year. About 50 million birds died during the six-month-long 2015 outbreak.

Culling the birds – which can be done with carbon monoxide, firefighting-like foam and other means – can take an emotional toll on the farmers who raised them. “Your entire life you work to keep birds healthy and now you’re doing things that are completely contrary,” said Puglisi, the Delaware farmer.

There are active outbreaks in more than a dozen states, suggesting the influenza is widespread, said Michael Osterholm, director of the University of Minnesota’s infectious-disease research and policy centre. There’s nothing “shutting off the faucet” and stopping the virus from spreading through waterfowl, he said.

“These are not birds you can capture and vaccinate,” Osterholm said. “These are not birds that basically stay in any one location … There really is no other animal species that could spread a virus like this nearly as effectively.”

Agriculture experts and farmers say there are low-cost ways to reduce the risk of an outbreak, such as limiting unnecessary visitors and curtailing animals’ movement between barns.

But even well-protected flocks have had outbreaks, said Krouse, with MPS Egg Farms. “The reality, unfortunately, right now is that the disease is still finding a way through,” he said.

With few long-term solutions, some industry observers are urging the US Government to invest more in research or in developing a vaccine.

Vaccination can limit options for chickens to be traded abroad because that could make it harder to determine whether asymptomatic birds are infected. Fifteen to 20 per cent of broiler chickens, meant to be eaten rather than used to lay eggs, are exported, according to the US Department of Agriculture (USDA).

It’s now common at many farms to require employees to shower and change before entering henhouses, dredge their shoes through pans filled with disinfectant and put clothes in a washer and dryer before leaving.

At Puglisi’s farm, delivery people leave packages at the farm’s perimeter. Few contractors are brought in; the ones who do enter the premises must be away from other bird facilities for 72 hours first.

Haulers picking up or delivering loads must show proof of an interior and exterior wash; Puglisi’s farm pays the cost, typically around US$100.

To deter migratory birds, the farm uses netting, propane cannons, lasers, pyrotechnics, speakers playing predatory bird calls and a spray that makes grass taste bad.

“It just goes on and on and on and on,” Puglisi said. “And honestly, if somebody was to tell me that if I stood on my head for an hour a day I could keep the virus out, I would try it because [an outbreak is] awful.”

In February 2022, Puglisi’s farm called the Delaware state veterinarian after noticing higher-than-normal death rates in one chicken house. For the next few months, a crew cleaned the facility and disinfected it by keeping buildings heated to at least 38C for four days. The farm was given a clean bill of health at the end of May and began slowly rebuilding its flock in June.

But culling the hens left a mark on Puglisi.

“It’s devastating,” he said. “I’ll carry it to the grave with me.”

– Washington Post