Bird Flu Cases Are Surging in 2026. What Does It Mean?

Bird flu is back with a vengeance, after subsiding temporarily in the summer and fall. The virus has been detected in 28 U.S. states since the beginning of 2026, affecting about half as many birds as it did in three months during the fall of last year, and prompting the governor of Colorado to declare a disaster in the state.

The uptick in infections in the last two months does not likely signal any increase in the infectiousness or resilience of the virus itself. Nevertheless, the virus has proven remarkably persistent since hitting the United States in 2022, with egg prices soaring and almost 200 million chickens being culled as a result.

“It’s global and ubiquitous at this point, and by every definition that I know of, it’s endemic,” Maurice Pitesky, an associate professor and expert in poultry disease modeling at the UC Davis School of Veterinary Medicine, tells Sentient. A disease is considered endemic when it persists indefinitely at a baseline level even when no new infections are brought in from other places.

When bird flu is detected in a U.S. poultry flock, the entire flock is slaughtered. That’s the primary method being used to stop the spread of the virus, but some experts say it’s not enough.

Recent Bird Flu Developments

Over 4.8 million birds have been affected by bird flu in January and the first week of February, according to USDA data, most recently including 1.3 million at a single Colorado facility and 1.5 million at a Pennsylvania farm. By contrast, less than 1.4 million birds nationwide were affected by avian flu over the three months of September, October and November of 2025.

It isn’t just the United States, either. This strain of bird flu is a worldwide pandemic that’s hit every continent except for Australia. It was detected in cattle in Europe for the first time in January when a Dutch cow was found to be infected. Poland has been hit particularly hard by the virus this year: Less than two weeks into 2026, it was reported that 1.3 million chickens were housed at infected facilities since the beginning of the year, most of whom were culled. Then, just one week after that, an additional 1.5 million hens were killed at a single Polish farm due to avian flu.

While the recent wave of infections is concerning, it doesn’t indicate that the pandemic has changed in any fundamental way. Avian flu infections wax and wane with the seasons, Pitesky tells Sentient, and the uptick in detections over the last few months is mostly attributable to the migratory patterns of the wild waterfowl from which the virus originates.

“We get seasonal outbreaks at the highest rate from about November to March, and that coincides with when we have the migratory waterfowl that are in greatest abundance in the United States,” Pitesky says. In the summer, the United States typically sees a few avian influenza outbreaks, he says, “but nothing like what we get in the wintertime, and it completely coincides with the migratory waterfowl.”

How Are We Trying to Fight the Virus?

There are several things governments are doing to stop the spread of avian flu — and some things they could be doing that they aren’t.

Avian flu has a mortality rate of 90-100% in chickens, according to the CDC, and there’s currently no treatment or vaccine widely available for it in the United States. The primary way farms combat the virus is by culling entire flocks once the virus is detected. When they do this, they receive what are called indemnity payments from the federal government to compensate them for their losses.

But this is a reactive policy that can only be implemented after some damage has already been done, not a proactive method for preventing flocks from getting infected in the first place.

Biosecurity

One way for poultry farmers to preempt infections is to implement biosecurity measures at their facilities. This includes policies like limiting the number of visitors, requiring hand-washing by those who contact live birds, cleaning and disinfecting equipment before transporting it to new facilities and removing wild bird nests in and around farms.

“For the last five years, we’ve really been working with our poultry producers to ensure that everybody is implementing enhanced biosecurity,” Maggie Baldwin, the Colorado state veterinarian, tells Sentient. “That is really our biggest defense against introductions of avian influenza — trying to separate the potential introduction from wild birds into domestic poultry species.”

The goal of biosecurity is to “limit that interaction between wild birds and the domestic poultry flock,” Baldwin says.

Farms that have already been infected with bird flu must undergo a biosecurity audit in order to receive future indemnity payments from the government if they become infected again. Beyond that, however, there’s no federal law requiring poultry farms to implement biosecurity measures to stop avian flu.

The closest is a federal-state partnership program called the National Poultry Improvement Plan. Poultry producers that enroll in this program must adopt certain biosecurity measures and undergo audits to make sure they’re properly implementing them. Many international buyers will only purchase products from farms that enact this biosecurity program. But enrolling in the plan is voluntary, not required by law.

Although biosecurity measures differ from farm to farm, they typically focus on what’s going on within the facilities. But the pathogen itself is believed to originate in wild waterfowl, who might live miles away from the farms that ultimately become infected.

For this reason, Pitesky is a proponent of what he calls “outward facing biosecurity.” This involves surveilling and monitoring the environments that surround bird farms to determine how the virus makes its way to farms and prevent it from doing so.

“The thing that we all have to realize is that the farm doesn’t change location, but the habitat around the farm changes,” Pitesky told Sentient last March. “Until we really understand what’s going on outside the facility, we’re just going to be reactive. We’re going to see which places get affected, and then we’re going to respond. But then a year later, it’s going to be something 50 kilometers to the west or east that gets hit.”

But Pitesky says the data that would be necessary to implement this kind of biosecurity — specifically, information on “the spatial and temporal relationship of waterfowl in close proximity to [bird] farms” — isn’t easily accessible. An investigation by Sentient last year confirms this. Crucial information that could help researchers combat the flu, including geospatial data about bird farms and demographic information about the birds themselves, is either not tracked, poorly tracked or shielded from public release through state and federal laws.

“I understand we want to protect farmers’ personal data, including farm location data, but we’ve taken that to this illogical conclusion,” Pitesky says. “We’re protecting their data, ostensibly to help farmers, and it’s not helping. We’re four years into an outbreak, and you have maybe a handful of people on the planet that have access to knowing where all the cases of [highly pathogenic avian influenza] in the United States are. That’s a problem, right?”

The Trump Plan

Last March, the Trump administration announced a “five-point plan” to fight avian flu and, in doing so, reduce egg prices. The plan included expanding several Biden-era programs, rolling back animal welfare laws, and restricting imports.

One of the Biden-era programs that the Trump administration extended is called Wildlife Biosecurity Assessments. This involves sending USDA staff to egg-laying facilities to identify any wildlife living on the premises and suggest strategies to remove them.

Assessments are provided free of charge to producers, but the program has some significant limitations. Only commercial egg-laying facilities are eligible, and the inspection only takes place on-site, without examining the surrounding environment. Perhaps most limiting, these assessments are not available to farms that have already been hit with avian flu.

What About a Vaccine?

“Vaccination, absolutely, is the biggest thing that I would like to see, and I would like to see it soon,” Baldwin tells Sentient. “We’ve been trying to ask USDA to get that approval process expedited, so we can start implementing that here in Colorado.”

Although some countries, such as France and Mexico, have had a degree of success in vaccinating their birds against the flu, the United States has only granted a conditional license to one company, Zoetis, for its bird flu vaccine, and has not approved the vaccine for commercial use. No bird flu vaccines are currently authorized for widespread use in the United States — and even if they were, it’s unclear whether or not poultry producers would use them.

That might sound counterintuitive, but some poultry companies are wary of a bird flu vaccine. Some experts fear that a vaccine could give the virus more chances to mutate into newer, more dangerous strains. Others argue that the farmworkers administering the vaccine to birds would themselves need to be vaccinated, and the United States has not released a bird flu vaccine for humans. All of this would be very expensive.

More broadly, many in the industry are concerned that the use of a vaccine could trigger trade bans against U.S.-produced chicken, which would cripple U.S. exports. The United States has done this to other countries: it implemented restrictions on European poultry after France began using a bird flu vaccine on ducks.

The United States did this for a reason. “The challenge in vaccination — not just for avian influenza, but for a lot of diseases — is that vaccination can sometimes mask disease,” Baldwin says. “So you might still have low levels of disease circulating in a vaccinated population.”

If this happens, a worry for importers might be that if they buy U.S. chicken that appears to be free of avian flu, it could still contain low levels of the disease and thus spread it to other nations. Baldwin says that if a bird flu vaccine were deployed in the United States, American producers would need to develop methods of ensuring that exported chicken was actually free of the disease, and not just free of its symptoms.

“It’s just a question of: can we get the surveillance that would be required to satisfy our international trading partners and ensure that our products are safe?” Baldwin says.

The Bottom Line

Amidst all of these concerns, it’s worth highlighting that the nature of the poultry industry itself bears a good deal of responsibility for avian flu’s spread.

Birds in poultry farms are housed in cramped and unsanitary conditions, often for their entire lives. The selective breeding of chickens to maximize their productivity results in lower biodiversity in flocks, and the factory farm model leads to hundreds of thousands of birds being housed in the same enclosures. All of these factors help bird flu spread faster than it otherwise would.

Mitigation strategies are constantly developing, and there may come a day when U.S. birds are vaccinated en masse against the virus. But as long as we’re producing and eating poultry products, it’s entirely possible that bird flu, and all of the havoc it causes, will simply become an enduring fact of life.