When the lethal H5N1 chicken flu virus made its first look at a U.S. poultry farm in February 2022, roughly 29,000 turkeys at an Indiana facility had been sacrificed in an try and avert a bigger outbreak.
It didn’t work. Three years later, extremely pathogenic avian influenza has unfold to all 50 states. The variety of industrial birds which have died or been killed exceeds 166 million and the worth of eggs is at an all-time excessive.
Poultry producers, infectious illness consultants and authorities officers now concede that H5N1 is probably going right here to remain. That recognition is prompting a few of them to query whether or not the long-standing observe of culling each single chicken on an contaminated farm is sustainable over the long-term.
As an alternative, they’re discussing such methods as focused depopulation, vaccinations, and even the relocation of wetlands and our bodies of water to lure virus-carrying wild birds away from poultry farms.
However every of those options entails quite a lot of logistical, financial and environmental prices that will eclipse the meant financial savings.
“People talk about common-sense solutions to bird flu,” mentioned Dr. Maurice Pitesky, a veterinarian and industrial poultry professional at UC Davis. “But that’s what mass culling is. There’s a reason we’ve been doing it: It’s common sense.”
The present model of the chicken flu — often called H5N1 2.3.4.4b — is each extremely contagious and extremely deadly. It has has plowed by the nation’s industrial chickens, turkeys and geese with a mortality charge of practically 100%.
“There’s a reason why they call it ‘highly pathogenic avian influenza,’” mentioned Angela Rasmussen, a virologist on the College of Saskatchewan’s Vaccine and Infectious Illness Analysis Group. “It just goes straight through a flock like a hot knife through butter.”
And it’s why most researchers and veterinarians promote mass culling, describing it as humane and cost-effective.
A pure dying from H5N1 just isn’t nice for a rooster, mentioned Rasmussen. The virus produces a gastrointestinal an infection, so the birds wind up dying of diarrhea together with respiratory misery.
“It’s like Ebola without the hemorrhage,” she mentioned.
Sparing birds that don’t look sick is of venture. They could be contaminated and in a position to unfold the virus by their poop earlier than they’ve any outward indicators of sickness. The one approach to know for positive is to check every chicken individually — an costly and time-consuming prospect. And if even a single contaminated chicken is missed, it might unfold the virus to a whole flock of replacements, Rasmussen mentioned.
In addition to, she mentioned, all the additional work that might go into ensuring some chickens can keep alive would solely drive up labor prices and finally make eggs dearer.
It additionally has the potential to extend the entire quantity of virus on farms, which is harmful for human poultry employees, mentioned Dr. Ashish Jha, dean of the Brown College Faculty of Public Well being.
“One of the reasons to cull early is that you don’t want a lot of bird-human exposures,” he mentioned. “The more infections we introduce to humans, the more mutations we’re going to see that increase the risk for a broader epidemic or pandemic.”
For all of those causes, worldwide commerce agreements require mass culling — also referred to as “stamping out” — in order that importers don’t get a facet of H5N1 with their poultry, mentioned Dr. Carol Cardona, a veterinarian and avian influenza researcher on the College of Minnesota.
That’s not the one monetary incentive for mass culling. The USDA reimburses farmers for eggs and birds that need to be killed to include an outbreak, however not for birds that die of the flu.
But at instances, this has meant killing greater than 4.2 million birds, most of which can have been wholesome.
Invoice Mattos, president of the California Poultry Federation, mentioned a extra focused strategy might be possible when all birds should not residing below the identical roof. In California, for example, farms that elevate broiler chickens sometimes function a number of stand-alone buildings with separate air flow programs, entryways and exits.
Biosecurity measures like these can hold pathogens from spreading between barns, Cardona mentioned. Dangers might be decreased additional by requiring employees to alter their garments and boots when shifting from barn to barn, or by assigning employees to a single barn, she mentioned.
However others, together with Dr. John Korslund, a veterinarian and former USDA researcher, are skeptical that such a observe may work, contemplating the virulence of H5N1.
“Chickens are infected and shedding virus very early, often before visible evidence of clinical illness,” Korslund mentioned. “Odds are that ‘healthy’ buildings on infected premises may be in reality in the early stages of incubating infections,” he mentioned.
Whereas it was potential some buildings may stay virus free, and a few birds might be salvaged, the downsides of this strategy are large, Korsland mentioned. “A lot of additional virus will be put into the environment,” he mentioned.
Certainly, flu particles from one facility can escape exhaust followers and journey nice distances, mentioned Michael Osterholm, director of the Heart for Infectious Illness Analysis and Coverage on the College of Minnesota. Research have proven that “the movement of virus from farm to farm was associated with wind direction and speed,” he mentioned.
Chook flu vaccines might supply some safety. Each China and France use them, and the USDA granted a conditional license this month for an H5N2 vaccine designed for chickens, in line with Zoetis, the corporate that developed it.
Whereas some are heralding vaccines as a possible device to inoculate the nation’s poultry farms, others say the prices might be an excessive amount of.
Most U.S. commerce companions should not eager to import poultry merchandise from nations that vaccinate their birds on account of issues that the pictures can masks the presence of the virus. And most will blackball a nation’s whole poultry portfolio, even when only one area or sort of poultry is contaminated.
The U.S. exports greater than 6.7 billion kilos of rooster meat annually, second solely to Brazil, in line with the Nationwide Hen Council. So so long as international patrons are immune to vaccination, the pictures in all probability received’t be deployed even when egg-laying hens are getting worn out by the virus.
As members of the U.S. Congressional and Senate Hen Caucuses wrote in a letter this month to the USDA, “if an egg-laying hen in Michigan is vaccinated for HPAI, the U.S. right now would likely be unable to export an unvaccinated broiler chicken from Mississippi.”
The brand new H5N2 vaccine may allay such issues. Whereas it could supply safety towards H5N1, it could elicit antibodies that look distinct from those that come up from an precise an infection, Cardona mentioned.
Pitesky mentioned that none of those measures will work if we don’t do a greater job with flu surveillance and farm placement.
Wildlife and agriculture officers ought to ramp up their testing of untamed birds to find out the place the virus is shifting and the way it’s evolving, he mentioned. That can require international coordination as a result of contaminated birds can journey forwards and backwards between the U.S., Canada, Russia, East Asia and Europe.
Poultry farms close to ponds, lagoons or wetlands that appeal to wild birds ought to be on excessive alert throughout migration season, Pitesky mentioned. Farmers ought to use apps equivalent to eBird, BirdCast or the Waterfowl Alert Community to maintain tabs on when the birds are close by to allow them to step up their biosecurity measures as wanted, he mentioned.
It could be potential to lure wild birds away from agricultural services by bolstering wetlands in additional distant areas, he mentioned.
“I keep pushing the idea of starting to reflood some of those wetlands, but we haven’t done it in any kind of strategic fashion,” Pitesky mentioned.
The thought is smart, however has been dismissed as “pie in the sky, which I push back on,” he mentioned. “I’m like, what we’re doing right now is obviously not working.”