Cambodia has reported another case of H5N1 bird flu, bringing the total number of cases in the country this year to nine, according to the country’s Health Ministry.
A 16-year-old girl from Chantrea in the southeastern Svay Rieng province was confirmed to have H5N1 bird flu, with symptoms of fever, cough, sore throat, and shortness of breath.
This is the second such case in less than a month in the Southeast Asian country, local news website VietnamPlus reported.
"Laboratory results from the National Institute of Public Health showed on Saturday that the girl was positive for H5N1 virus," the statement released late Saturday said.
The patient, who is in severe condition, is getting intensive care from a team of doctors, it added. Health authorities are looking into the source of the infection and are examining any suspected cases or people who have been in contact with the victim in order to prevent an outbreak, the statement added.
Among the nine human cases of H5N1 bird flu so far this year were eight children, one of whom died, and an adult. All the patients reportedly had a history of exposure to sick or dead poultry prior to their illness.
The US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) has confirmed three more H5N1 avian influenza outbreaks in dairy cattle, raising the national total to 181 from 13 states.
The latest confirmations are from Colorado, South Dakota, and Texas.
In other updates, APHIS also reported more detections in wild birds in mammals. The group reported about more than 100 more H5N1 detections in wild birds across several states. Some were waterfowl taken by hunters and were sampled last fall. However, several were agency-harvested birds from Colorado's Weld County, which has been a recent hot spot for dairy cow outbreaks, poultry outbreaks, and human illnesses. Species in Weld County that tested positive included doves, sparrows, starlings, and pigeons.
Regarding mammals, APHIS over the past few days has reported 27 more detections, raising its confirmed number to 373. Most of the newly confirmed positives involve deer mice and house mice from Weld County in Colorado. The group also included three domestic cats from Larimer County in Colorado, plus a rabbit and a vole from Weld County.
A small study in Texas suggests that human bird flu cases are being missed on dairy farms where the H5N1 virus has taken off in cows, sparking an unprecedented nationwide outbreak.
The finding adds some data to what many experts have suspected amid the outbreak. But the authors of the study, led by researchers at the University of Texas Medical Branch in Galveston, went further, stating bluntly why the US is failing to fully surveil, let alone contain, a virus with pandemic potential.
"Due to fears that research might damage dairy businesses, studies like this one have been few," the authors write in the topline summary of their study, which was posted online as a pre-print and had not been peer-reviewed.
The study authors, led by Gregory Gray, were invited to two undisclosed dairy farms in Texas that experienced H5N1 outbreaks in their herds starting in early and late March, respectively. The researchers had a previously approved research protocol to study novel respiratory viruses on dairy farms, easing the ability to quickly begin the work.
Rare study
"Farm A" had 7,200 cows and 180 workers. Illnesses began on March 6, and nearly 5 percent of the herd was estimated to be affected during the outbreak. "Farm B" had 8,200 cows and 45 workers. After illnesses began on March 20, an estimated 14 percent of the herd was affected.
The researchers first visited Farm A on April 3 and Farm B on April 4, collecting swabs and samples at each. Based on the previously approved protocol, they were limited to taking nasal swabs and blood samples from no more than 10 workers per farm. On Farm A, 10 workers provided nasal swabs and blood samples. On Farm B, only seven agreed to give nasal swabs, and four gave blood samples.
While swabs from cows, milk, a dead bird, and a sample of fecal slurry showed signs of H5N1, all of the nasal swabs from the 14 humans were negative. However, when researchers looked for H5N1-targeting antibodies in their blood—an indicator that they were previously infected—two of the 14, about 14 percent, were positive.
Both of the workers with previous infections, a man and a woman, were from Farm A. And both reported having flu-like symptoms. The man worked inside cattle corrals, close to the animals, and he reported having a cough at the time the samples were taken. The woman, meanwhile, worked in the cafeteria on the farm and reported recently recovering from an illness that included fever, cough, and sore throat. She noted that other people on the farm had similar respiratory illnesses around when she did.
The finding suggests human cases of H5N1 are going undetected. Moreover, managing to find evidence of two undetected infections in a sample of just 14 workers suggests it may not be hard to find more. The Centers for Disease Control and Prevention estimates that around 200,000 people work with livestock in the US.
A “compelling case”
To date, the virus has infected at least 175 dairy farms in 13 states. The official tally of human cases in the dairy outbreak is 14: four in dairy farm workers and 10 in workers on poultry farms with infections linked to the dairy outbreak.
"I am very confident there are more people being infected than we know about," Gray told KFF, which first reported on the study. "Largely, that’s because our surveillance has been so poor."
Known infections in humans have all been mild so far. But experts are anxious that with each new infection, the wily H5N1 virus is getting new opportunities to adapt further to humans. If the virus evolves to cause more severe disease and spread from human to human, it could spark another pandemic.
Federal officials are also worried about this potential threat. In a press briefing Tuesday, Nirav Shah, the CDC's principal deputy director, announced a $5 million effort to vaccinate farm workers—but against seasonal flu.
Shah explained that the CDC is concerned that if farm workers are infected with H5N1 and the seasonal flu at the same time, the viruses could exchange genetic segments—a process called reassortment. This could give rise to the pandemic threat experts are worried about. By vaccinating the workers against the seasonal flu, it could potentially prevent the viruses from comingling in one person, Shah suggested.
The US does have a bird flu-specific vaccine available. But in the briefing, Shah said that the use of that vaccine in farm workers is not planned for now, though there's still active discussion on the possibility. The lack of severe disease and no documented human-to-human transmission from H5N1 infections both argue against deploying a new vaccine, Shah said. "There has to be a strong and compelling case," he added. Shah also suggested that the agency expects vaccine uptake to be low among farm workers.
A 15-year-old girl from southeast Cambodia's Prey Veng province died of H5N1 avian influenza on Tuesday, the Ministry of Health said in a press statement.
The patient lived in Kanhchriech district's Por Marinh village.
Health experts were looking into the source of the infection and examining any suspected cases or people who have been in contact with the victim in order to prevent an outbreak in the community, said the statement.
According to the ministry, a total of 10 human cases of H5N1 bird flu have been recorded so far this year.
As bird flu spreads in cats, cows and other animals, it has more opportunity to adapt to easily infect humans.
(Excerpts)
The Colorado Department of Public Health announced on August 9 that six cat infections in the state have been confirmed this year. Two of those detections were in samples collected in May, but at least three were in samples collected in July. What’s particularly worrying about the new announcement is that two of the infected cats were indoor animals.
_________
In Colorado the disease appears particularly pervasive: more than eight million commercial chickens to date have died because of the outbreak, more than 60 dairy herds have confirmed cases of avian influenza, and 10 human infections have also been confirmed.
__________
If the first concern is the sheer quantity of avian influenza virus in the environment, the second is the number and variety of animals it is continuing to infect unchecked. Each new infection represents an opportunity for the dairy strain of the avian influenza virus to meet and mingle with whatever other flu viruses are present in the new host. Flu “viruses are notorious for developing mutations or taking genes from other viruses,” Barron says. “At what point is there risk that the virus changes and now makes people severely ill?”
As bird flu spreads in cats, cows and other animals, it has more opportunity to adapt to easily infect humans.
(Excerpts)
The Colorado Department of Public Health announced on August 9 that six cat infections in the state have been confirmed this year. Two of those detections were in samples collected in May, but at least three were in samples collected in July. What’s particularly worrying about the new announcement is that two of the infected cats were indoor animals.
_________
In Colorado the disease appears particularly pervasive: more than eight million commercial chickens to date have died because of the outbreak, more than 60 dairy herds have confirmed cases of avian influenza, and 10 human infections have also been confirmed.
__________
If the first concern is the sheer quantity of avian influenza virus in the environment, the second is the number and variety of animals it is continuing to infect unchecked. Each new infection represents an opportunity for the dairy strain of the avian influenza virus to meet and mingle with whatever other flu viruses are present in the new host. Flu “viruses are notorious for developing mutations or taking genes from other viruses,” Barron says. “At what point is there risk that the virus changes and now makes people severely ill?”
We were strongly critical of the Chinese Communist Party over its handling of the Covid outbreak, but I think we have to make an apology. It turns out that the US government is even worse with its deliberate cultivation of the nascent bird flu epidemic.
That certainly appears to be the case, to me it is astonishing the amount of freedom the US government has yielded to the H5N1 bird flu...I was shocked when I first read that indoor cats have caught the virus...Are there human carriers now or did the cats interact with infected mice who came from outside?...Or have the cats simply got out of the house once or twice accidentally and if so what are the odds an indoor cat catches H5N1 bird flu that one time it gets out of the house?...Perhaps H5N1 bird flu is more widespread in many various animal species in the US, more than currently understood, the revelations written in that article are very concerning...
A man in Missouri has become the first American to be diagnosed with H5N1 bird flu without coming into contact with animals, in a potentially worrying development.
They are the 14th person to become infected in the US since the strain hit livestock earlier this year - but the first not to have been directly exposed to an infected bird or cow.
It is still unclear how the Missourian was infected, but experts have been warning for months against drinking raw milk because of fears the virus can spread to people via this route.
Another option is that he caught the virus from someone who was sick - though state health officials insist 'the risk of sustained transmission or infection among the general public remains low'.
After being hospitalized on August 22, the unnamed Missouri patient was tested for a battery of illnesses, and the Missouri Department of Health and Senior Services (DHSS) reported that he had the H5N1 virus.
He told officials that he had not been exposed to animals, which means they are unsure where he got the virus from. The patient had several 'underlying medical conditions' but recovered in the hospital and was discharged and sent home.
Federal officials have confirmed that three California dairy herds have suffered outbreaks of H5N1 bird flu, due most likely to the transportation of cattle and not exposure to diseased birds.
Health officials announced last week that they suspected cows at three Central Valley dairies had contracted the illness, and were awaiting testing for confirmation. On Tuesday, officials said those tests revealed that the strain of virus that infected California herds was nearly identical to that found in Colorado dairy herds — suggesting the infections were the result of interstate transfer of cattle.
The B3.13 genetic sequence found in the infected cows was clearly the result of “anthropogenic movement; essentially zero chance it was an independent spill from wild birds into these dairies,” said Bryan Richards, the Emerging Disease Coordinator at the U.S. Geological Survey’s National Wildlife Health Center. “So, if anyone is trying to blame wild birds: Nope!”
In a statement from the California Department of Food and Agriculture, officials said there were no confirmed human cases of H5N1 bird flu in the state, and neither the U.S. Centers for Disease Control and Prevention nor state officials see this development as a significant public health threat; the risk to humans is considered low.
Reports of H5N1 bird flu outbreaks at California dairy herds are continuing to rise as the nation's largest milk producer scrambles to contain the spread.
On Monday, officials reported that the number of infected dairy herds in the Central Valley had doubled over the weekend, rising from 17 to 34.
A spokesman for the California Department of Food and Agriculture said they expect more cases to be announced in the coming days and weeks, as testing continues.
With roughly 1,100 dairy herds in California—and 90% located in the San Joaquin Valley—concern is palpable, say industry insiders. Outbreaks interrupt milk production at affected dairies. Not only are the infected herds quarantined, but special testing must be conducted at nearby dairy farms as well.
"Farmers are genuinely worried about the virus and do not feel it's under control," said Anja Raudabaugh, CEO of Western United Dairies, the trade association of California dairy farmers. She added the industry is hoping a vaccine for cows will be developed "that would protect our animals" and be compliant under trade agreements.
The threat to humans is considered low. However, infectious disease experts worry that the longer the virus remains present in dairy farms, the greater the likelihood it could mix with a human virus and pose a greater risk to people.
Both state and federal health officials say milk is safe to drink, as long as it has been pasteurized.
Steve Lyle, an agriculture department spokesman, said the agency's call to test dairies within six miles of infected herds, as well as dairies that share personnel or equipment with infected herds, has allowed officials to detect infected dairies "at about the time or just before they are showing clinical signs –- during their incubation period."
The U.S. Department of Agriculture is working on a bovine vaccination for bird flu, but noted in a statement that this does not mean efforts to control the virus have failed.
"The pursuit of bovine vaccine development does not mean that biosecurity measures have failed," the agency said in a prepared statement. "Nor does it mean that USDA believes the virus is here to stay. Vaccine development is one part of an overall strategy that includes enhanced and strengthened biosecurity efforts to contain the virus and help mitigate spread."
The statement went on to say that a vaccine could prove helpful in eliminating the virus from the nation's dairy cattle, but it's just one tool.
"We continue to deploy all available efforts, including biosecurity and mandating the testing of lactating dairy cattle moving across state lines," the statement said.
It is still unclear how the virus got into the state, but genetic sequencing suggests the virus is similar to that found in infected cattle in other states—and that it did not come from wild birds.
It is also unclear what impact the disease will have on milk production in the state, although Raudabaugh said it will not affect milk prices.
"Dairy is a 'loss leader' at the grocery store," she said, and is often the major incentive for other items in the store.
A 'healthy' teenager is in critical condition after catching bird flu in Canada. And in a potentially alarming development, health officials say it's not clear how they became infected.
Health officials are still identifying the strain, but the patient is assumed to have H5N1, the virus that has infected dozens of Americans this year.
Almost all of the US cases were farm workers with direct contact with infected cattle or birds - but the case in Canada is different.
The teen had not visited farms but had been exposed to dogs, cats and reptiles, according to provincial health officer Bonnie Henry. 'That is absolutely an ongoing investigation,' said Henry.
The patient, who has not been identified, is currently being treated in a children's hospital in British Columbia. Henry said: 'This was a healthy teenager prior to this, so no underlying conditions.
'It just reminds us that in young people this is a virus that can progress and cause quite severe illness and the deterioration that I mentioned was quite rapid.'
The teen who is Canada's first bird flu victim in the latest outbreak - began suffering a fever, cough and 'pink eye' on November 2.
They were admitted to hospital on November 8, where their condition deteriorated further.
The patient is now suffering from severe lung damage making it hard to get oxygen around the body.
(Excerpt) A Canadian teenager who is in critical condition after contracting H5N1 bird flu was infected with a version of the virus that is different from the one circulating in dairy cattle in the United States, Canadian authorities announced Wednesday.
The National Microbiology Laboratory in Winnipeg confirmed the infection was indeed caused by the H5N1 virus. But genetic sequencing showed that it is of a genotype that has been found in wild birds, not the version that has been circulating in dairy cattle in the U.S.
California has declared a state of emergency for H5N1 bird flu amid fears that the virus could jump to people and start to spread. The move comes in response to a major outbreak of the virus among the state's cattle which has spilled over and infected dozens of dairy workers. The announcement follows news that an individual in Louisiana was hospitalized with H5N1, becoming the country's first severe case.
The declaration of emergency gives California state and local resources to contain the outbreak, including hiring staff or issuing contracts for things like tests or personal protective equipment (PPE). Governor Gavin Newsom said the move would free up funds and 'streamline and expedite' the state's efforts to tackle the outbreak. California also declared an emergency over the Covid pandemic, which was lifted in February 2023 after nearly three years.
California has identified H5N1 in 645 dairy herds since its first detection in late August and nearly half of those were reported in the past 30 days, highlighting the rapid spread of the virus. Thirty-four of the US' 61 human bird flu cases have also been in California. Many commentators, including officials at the World Health Organization, have criticized the U.S. response to the outbreak. Experts have described it as a pandemic 'unfolding in slow motion.' Until last month, nearly all testing of cattle and of people exposed to infected cows voluntary.
Announcing the state of emergency today, Newsom said: 'This proclamation is a targeted action to ensure government agencies have the resources and flexibility they need to respond quickly to this outbreak. 'Building on California's testing and monitoring system — the largest in the nation — we are committed to further protecting public health, supporting our agriculture industry [and] ensuring that Californians have access to accurate, up-to-date information. 'While the risk to the public remains low, we will continue to take all necessary steps to prevent the spread of this virus.'
The CDC also insists the risk of H5N1 to people is low and there is no evidence of human-to-human transmission, which would be needed to cause a large outbreak. There have been 61 official human cases since 2023, with the CDC identifying seven more 'probable' cases. Thirty-seven of the 61 cases have been traced to interaction with infected cattle, with the remaining infections caused either by diseases birds or an unknown source.The outbreak of H5N1 in dairy cattle is thought to have begun in Texas early this year. As of Wednesday, 865 infected herds had been identified in 16 states. But there is growing concern among experts that if allowed to spread unchallenged, the virus will evolve to infect people better. Every time the virus spreads, particularly between two different species, it acquires mutations which could change the way it behaves.
A record number of humans, cattle and birds have been infected with bird flu this year, in a wave that experts have called 'astounding.'
And this week, the US reported its first severe human case of H5N1 — with California declaring a state of emergency over the virus just hours later.
The CDC still says the virus poses a 'low' threat to the public, adding there is no evidence it has started to spread from person-to-person.
But infectious disease experts are alarmed over the figures, warning the scale of cases and every infection outside of birds raises the risk of the virus gaining mutations, allowing it to spread between people.
Dr Marc Johnson, a virologist at the University of Missouri, said on X: 'This virus might not go pandemic, but it is really trying hard, and it sure is getting a lot of opportunities.'
Experts have sounded the alarm about a 'very concerning' development in America's bird flu outbreak which could lead to a new super virus. In Nevada, officials have discovered that a second, more deadly strain has jumped from birds to cows, marking only the second time such an event has occurred. Experts now fear if both strains of H5N1 infect the same cow, the viruses could merge to form a new pathogen that is more infectious or deadly in people.
This so-called 'recombinant event' is common among avian flu and is what led to the 2009 swine flu epidemic. Dr Krutika Kuppalli, an infectious disease physician at the University of Texas Southwestern Medical Center, called the development 'very concerning' in an X post, as it 'may be connected to more severe disease in humans.'
The US Department of Agriculture (USDA) said Wednesday it detected the D1.1 form of H5N1 - bird flu - in milk samples from six cattle herds. It's unclear where in the state the herds were located.
This is a different strain from B3.13, which has infected over 900 cattle herds in 16 states. Up until this point, D1.1 had only been found in wild birds and poultry.
Dr Louise Moncla, an evolutionary biologist who studies H5N1 at the University of Pennsylvania, told The New York Times: 'This is not what anyone wanted to see. 'We need to now consider the possibility that cows are more broadly susceptible to these viruses than we initially thought.'
In November, an otherwise healthy 13-year-old girl from British Columbia, Canada, was infected with D1.1 bird flu from an unknown source. She had not been exposed to any birds or cattle, and her only risk factor was obesity. She went into respiratory failure and had to be placed on life support, though she eventually recovered. And a 65-year-old patient in Louisiana died last month after being hospitalized with severe respiratory symptoms from D1.1.
As of February 5, 67 Americans have been infected with H5N1 in 10 states, with the majority in California, according to the latest CDC data. And 957 dairy herds in 16 states have been infected, with most in California and Colorado.
The same version of the bird flu that has caused the most serious human illnesses in North America has now turned up in dairy cows. Cattle in Nevada tested positive for the H5N1 viral variant D1.1, which has been circulating in poultry and wild birds. It’s the first time this version has been detected in dairy cattle, the U.S. Department of Agriculture announced February 5.
“What [experts] are concerned about is that it could indicate another independent spillover event into dairy cows,” says veterinarian and environmental epidemiologist Meghan Davis of the Johns Hopkins Bloomberg School of Public Health. The risk of H5N1 still remains low for most people, she notes.
For about a year, a different H5N1 variant called B3.13 has been wreaking havoc among dairy cattle in the United States. Nearly 1,000 herds across 16 states have tested positive for H5N1. Cow infections led to 40 of the 67 confirmed human cases of highly pathogenic avian influenza in the United States since early 2024, according to the U.S. Centers for Disease Control and Prevention. None were caused by human-to-human transmission.
Most human infections have been in farm workers who presented mild symptoms, such as pink eye, fever and a cough. Two serious cases arose late last year, in a Louisiana man over the age of 65 and a Canadian 13-year-old girl. The Louisiana man became the first person in the U.S. to die with H5N1, while the Canadian teen is now in recovery. Both patients caught the D1.1 version of the virus, the one newly identified in cows.
Science News spoke with Davis to learn more about the implications of finding a second H5N1 variant in dairy cows. The conversation has been edited for length and clarity.
SN: What does finding the H5N1 variant of bird flu called D1.1 in dairy cattle mean?
Davis: For the past year, the hypothesis has been that there was a single spillover event in late 2023 and subsequent cow-to-cow spread. If we now have a new spillover event, there are two things that we immediately need to think about.
The first is it’s happening more often than we think. Are we going to see these sporadic cases on dairy farms? These would be on farms that might not have risk factors that we’ve been working to identify to date. We may need to be thinking far more seriously about improving the level of biosecurity on dairy farms.
Another concern I have is that when we are looking at disease related to [B3.13], this has been by and large mild. But we have seen more severe human illness with the D1.1. I do worry that the clinical presentation in [dairy] workers and other people exposed to the dairy cows or their products could be different and potentially more severe.
SN: What does this finding mean for H5N1 spread in humans?
Davis: We’re talking about a strain that we have seen in poultry, so we have had exposures in poultry workers.
We don’t know yet what kind of presentation we’re going to see in the cows. If [many copies of the D1.1 virus are] in the milk, then we could have those same splash exposures in the milking parlor [as seen with the B3.13 version]. There could be other ways in which dairy worker exposure could be different than poultry worker exposure. That could influence not only whether they’re exposed, but the route of exposure that could influence disease.
SN: What are viral variants, and how can different versions of a virus act differently?
Davis: When we think about genetic relatedness, [D1.1 and B3.13] are very close, like siblings. There are some ways in which they’re going to behave the same, and some ways they may behave differently. Even within a strain, if you have mutations, that could set up new characteristics.
These changes [can] set up a selective advantage for the virus — so it’s good for the virus, in terms of transmission, or is bad for us in terms of antiviral resistance or the ability to cause more severe disease. If there is a competitive advantage, these strains could become more dominant, and that’s a problem.
SN: What do we need to do to stay on top of the H5N1 bird flu outbreak in dairy cattle?
Davis: The identification of [D1.1 in cattle] was through an enhanced surveillance program that’s just come online relatively recently. Through [the USDA’s National Milk Testing Strategy], there is testing by states of bulk milk tanks and sometimes of individual farm bulk milk. This is a way to do high-level screening of your herds.
I think what this shows us is that if we can get new spillover events, then we need to maintain much more rigorous active surveillance and passive surveillance programs for this so that we are able to identify new spillover events as they occur.
America's food supply is under attack. It is long past time to fight back. I'm a third-generation poultry farmer in Saranac, Michigan. Over nearly seven decades, my family farming operation has grown to be the 10th largest egg producer in America. Herbruck's Poultry Ranch raises nearly 11 million birds in operations across Michigan, Indiana and Pennsylvania. You may even have purchased some of our eggs at your local grocery store. Believe me when I say the poultry industry is in crisis.
Since 2022, 153 million commercial, backyard and wild birds across 48 states have been infected by H5N1 – a novel strain of bird flu. Millions more animals have been euthanized to stop the spread of the virus. I liken this avian flu scourge to a terrorist attack because it undermines one of the country's most critical systems – our food supply. And poultry farms have been fighting this battle for years. But regrettably there's no end in sight to this war. And now American consumers are sharing the burden.
A recent surge in the virus has triggered more culls, devastated farms and resulted in skyrocketing grocery prices. A dozen eggs, which should wholesale for about $2, have spiked to $8 and higher. At Herbruck's Michigan farm, we experienced an outbreak in April 2024. All of us at Herbruck's were devastated to learn about the detection, and as someone who has cared for and depended on egg-laying hens for more than 60 years, I'm heartbroken by the loss of any hen.
Once avian flu is in the flock, it moves with frightening and deadly speed. We first detected the virus the day before Easter when we lost 70 birds in one of our barns. By Easter Sunday, 700 were dead. The following day, the death toll had climbed to 10,000. By Tuesday, two other farms within five miles of each other were also hit - that was when the United States Department of Agriculture (USDA) moved in.
After it is confirmed that avian flu has infected a farm, the USDA essentially takes over – and their policy is to 'stamp out' the virus. Within a week, we lost 6.5 million hens, which means 6 million fewer eggs per day were being produced and sold in the market. To a family farmer – that's emotionally and financially devastating. To the American consumer – it's a gut punch. These culls are not easy to bounce back from.
It will take months to repopulate our farm. After working with federal and state regulators and ensuring our farm was free and clear of the virus in June, we are still only operating at 70 percent of our full production capacity. Coupled with biosecurity protocols, the USDA policy of ‘stamping out’ the avian flu has worked to control the spread of bird flu in the past. But with new strains of bird flu, and the unprecedented infections of dairy cattle, we can no longer rely solely on biosecurity to protect our flocks.
America must start to vaccinate its poultry populations against avian flu just as we’ve vaccinated against Newcastle disease, infectious bronchitis and a handful of other illnesses for decades. Why is avian flu allowed to persist? Even though H5N1 vaccines exist and are made in America, we are not allowed to give them to our birds. Our federal government must take urgent, critical measures to help address this crisis, and that means implementing an aggressive strategy on vaccines.
We need enhanced, universal biosecurity requirements across the agriculture industry, and a strategic initiative that engages experts in the industry to expand our knowledge on bird flu and how we can further mitigate this crisis. If we effectively address bird flu, customers will see relief at the grocery store. And Americans will no longer have to pay the price for this preventable disease.
It will take a renewed scientific and political will to address the vulnerability of our nation’s food supply. But it can be done. We can't delay – or our goose may be cooked.
The progression of the species-jumping disease has been unprecedented, including the first-ever U.S. cases of infections in dairy cattle and heightened pandemic risks.
The bird flu that has been growing more pervasive during the last few years has infected more than 500 species, including 485 avian and at least 70 mammal.
The outbreak is being described as the fastest spreading and largest ever, posing a significant threat to biodiversity worldwide. The avian invader is pushing the boundaries of what we thought we knew about animal diseases. The highly transmissible bird flu, also known as H5N1, has been sweeping across the United States leaving a trail of dead chickens and empty egg cartons, and worried public health officials.
The virus has infected over 138 million birds across all 50 states and Puerto Rico, and spread to millions more on five more continents.
What started as a typical bird flu outbreak four years ago has evolved into a cross-species threat that's ruffling far more than feathers. As 2025 gets underway, the avian flu is ramping up. Jumping species. Dolphins and polar bears have it. So do smaller mammals such as wild foxes, skunks, and seals, leaving many dead or with neurological symptoms.
The progression of the bird flu in America since 2021 has been unprecedented, including the first-ever cases of infections in dairy cattle and raising heightened pandemic risks.
Chris Walzer is the Wildlife Conservation Society’s director of health and a board-certified veterinarian who has been warning of avian influenza’s devastating and worldwide impact on wildlife for more than a year. He is also a professor of conservation medicine at the University of Veterinary Medicine in Vienna, and said bird flu is highly transmissible, spread through droplet and feces-borne infections, and exacerbated by climate change-altering migration schedules for birds and its circulation, again and again, through domestic poultry.
“The bird flu outbreak is the worst globally and also in U.S. history, with hundreds of million birds dead since it first turned up in domestic waterfowl in China in 1996,” Walzer said in a statement one year ago. “H5N1 now presents an existential threat to the world’s biodiversity."
'A nightmare'
For the poultry industry, it's been a nightmare. Bird flu has wiped out entire flocks of egg-laying hens – and bears, coyotes, cows and raccoons. On Jan. 17, Georgia confirmed its first H5N1 outbreak at a commercial farm. The spread occurred at a broiler farm housing 45,500 birds in Elbert County, in the northeastern part of the state.
This event is particularly significant because Georgia is the nation's leading state for chicken production. In response, Georgia officials implemented a ban on poultry exhibits, including sales of live birds at markets and other gatherings featuring live birds.
Rose Acre Farms, the nation's second-largest egg producer, this week confirmed an avian flu outbreak at its facility in Seymour, Indiana, with 2.8 million birds, sure to further strain the already tight egg supply.
The widespread losses in bird populations are expected to have a substantial impact on egg prices. Predictions indicate that egg prices may reach record highs later this year. This month, consumers were already encountering vacant shelves and escalating prices for eggs in grocery stores across the nation. Each time a flock of egg-laying hens has been wiped out, farmers must scramble for new chicks. The result? Empty shelves and sky-high prices at the grocery store. Your morning omelet might soon require a small loan.
'Unprecedented'
The virus is showing an alarming ability to jump species. In 2023, it made its arctic debut, claiming a polar bear in Alaska. It's now been found in at least 48 mammal species, many of which had never been diagnosed with avian influenza before.
The bird flu primarily hitches a ride with migratory birds, especially ducks and geese. These frequent flyers serve as nature's viral delivery service, spreading H5N1 across vast distances during their seasonal travels "This is an unprecedented situation," said Nichola Hill, an infectious disease ecologist at the University of Massachusetts Boston. "We've never seen a bird flu virus persist in wild birds for this long or spread this widely."
The virus poses a threat not only to poultry but also to various animals, including house pets, who like other animals can become infected by consuming contaminated birds or through exposure to infected environments. The best way to prevent your pets from catching bird flu is to minimize the risk of being infected by it. To do that, health authorities recommend:
• Avoid contact with sick or deceased birds or animals.
• Refrain from consuming raw milk or meat.
• Do not feed pets raw or contaminated food.
• Backyard bird enthusiasts should wear gloves and disinfect bird-feeders.
• Keep pets away from wild animals.
Cats, in particular, are susceptible to H5N1. They can contract the virus by snacking on infected birds or hanging out in contaminated environments. Dogs aren't off the hook, either, though they seem less likely to catch it than their feline counterparts. The fatality rate for the current strain of H5N1 in cats hovers around 67%.
Spread to humans
As of this month, 67 human cases of H5N1 have been reported in the United States. One man died. Despite those numbers the risk to public health remains low, but health officials are closely monitoring the situation due to the virus's ability to infect mammals, including humans. Job-related or recreational exposure to infected birds increases the risk of human infection. People at higher risk include farmers, poultry workers, backyard flock owners, animal care workers and public health responders.
The scientific community remains vigilant about the potential for the H5N1 virus to mutate and acquire the ability to spread efficiently between humans, which could potentially lead to a pandemic. Similar outbreaks in Europe and North America underscore recurring risks driven by migratory pathways, with ongoing viral evolution and reassortment leading to over 100 genotypes.
Each new infection gives the virus an opportunity to randomly mutate as it replicates, and if different strains of the virus infect a new host simultaneously, there is a risk of Patient Zero. The Centers for Disease Control and Prevention and other health agencies are closely monitoring the situation, tracking factors such as virus transmission patterns, disease severity, case distribution and genetic changes in the virus.
The bird flu outbreak is so devastating it has caused billions of dollars in losses in the U.S. alone from poultry culling and decreases in agricultural productivity, and it has renewed calls for vaccination strategies and improved biosecurity worldwide.
The virus has evolved so many times and jumped dozens of species it has researchers in several peer-reviewed journals, such as the Journal of the American Veterinary Medical Association, Emerging Infection Diseases and Emerging Microbes and Infections, warning that the scientific community has to stay abreast of any mutations and share all the information possible to ensure a future version does not set into humans and become the next global pandemic.
The virus is reshaping ecosystems, affecting everything from endangered species to entire food chains. It's a stark reminder of the delicate balance of nature and how easily it can be disrupted, as it was during the height of the COVID pandemic. Nobody wants to see what that might look like.
A woman in Wyoming was hospitalized with H5N1 bird flu, according to health officials who say she was likely infected by handling sickened birds in a backyard flock. According to a statement from Wyoming's public health department, the woman is "an older adult" and has "other health conditions," which may have made her more susceptible to the disease. She is being treated in another state.
This marks the first human case of bird flu in Wyoming and the 70th human case in the United States since 2024. Although the U.S. Center for Disease Control and Prevention's website lists only 68 human cases on its website, it does not yet include this case or another announced earlier this week in a poultry worker from Ohio. She is also the fourth person in North America to have been hospitalized with the disease. One person in Louisiana died from the infection.
It is not clear whether she was infected with the D1.1 version of the H5N1 virus, which is now widespread in wild birds, poultry and cattle herds in Nevada and Arizona — or the B3.13 version, which is associated with the vast majority of dairy herds.
According to the U.S Department of Agriculture, 968 dairy herds have been infected across 16 states — this does not include the herd in Arizona that was reported earlier this week. “While this is a significant development as bird flu activity is monitored in Wyoming and across the country, it is not something we believe requires a high level of concern among most Wyoming residents,” said Dr. Alexia Harrist, state health officer and state epidemiologist with the Wyoming Department of Health.
H5N1 has been reported in wild birds in Wyoming. There have also been reported infections in the state's commercial poultry and dairy cattle. Harrist and the CDC say there is no evidence of human-to-human transmission of the virus, and the risk for the general public remains low. She recommended that people do not eat raw or undercooked eggs, meat or other animal products, that they avoid contact with wild birds, and that they don't touch sick or dying wild or domestic birds. She also said people should not drink raw milk or raw milk dairy products.
Leading health experts have warned that the US is staring down the barrel of another pandemic as bird flu spirals out of control on US farms.
So far, the H5N1 outbreak has affected nearly 1,000 dairy cow herds and resulted in more than 70 human cases, including the first confirmed death.
The US poultry industry is at significant risk, say experts from the Global Virus Network (GVN), particularly in areas with high-density farming and where personal protective practices may be lacking.
Since 2022, more than 168 million poultry in the US has been lost or culled due to the bird flu outbreak in America, which has caused the price of eggs to skyrocket.
Although human-to-human transmission has not yet been observed, experts caution that mutations and reassortments — when two viruses simultaneously infect a host and exchange genetic material — could raise the risk of it occurring.
The GVN is now urging world governments to confront the threat of H5N1 avian influenza by strengthening surveillance efforts and enforcing stricter biosecurity protocols.
The organization also warns that countries must prepare for the possibility of human-to-human spread to avoid a chaotic chain of events reminiscent of the early days of the COVID-19 pandemic.
