Category: Flu Virus

Three poultry workers from a farm in northeast Colorado are suspected of contracting bird flu, state and federal health officials announced Friday.

Specimens have been sent to the CDC for confirmation. The workers who tested presumptive positive had mild symptoms and were helping with the depopulation of poultry at a facility dealing with an H5N1 outbreak.

The H5 bird flu is spreading among wild birds and causing outbreaks in dairy cows and poultry across multiple states. The CDC is sending a team to Colorado to assist with the ongoing investigation at the states request.

There have been four confirmed human cases of bird flu in the U.S. since March, all in farmworkers, with two in Michigan, one in Texas and one in Colorado, the CDC said.

In the latter case, a Northern Colorado farm worker developed pink eye after direct contact with cattle infected with avian flu, according to the CDPHE.

The U.S. Department of Agriculture has confirmed bird flu outbreaks in 152 cattle herds so far this year.

The CDC stated that the risk to the public from bird flu remains low, with no signs of unexpected increases in flu activity in Colorado or other states affected by H5 bird flu outbreaks in cows and poultry.

However, the CDC added that human infections with this novel influenza virus (and others) are concerning because of the potential to cause severe disease.

Federal officials are considering when to deploy 4.8 million doses of the bird flu vaccine. Last month, Finland announced it would offer shots to workers who might be exposed to the virus.

Related:Research affirms that pasteurized dairy is safe from avian flu

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Bird flu suspected in 3 Col. poultry workers, CDC investigates - AGDAILY

Bird flu or avian influenza cases in humans are on the rise in the US sparking fear of another pandemic similar to Covid-19. Four dairy workers have tested positive for H5N1 strain in the country amid massive spread of the virus in dairy cows. While there have been no cases of human-to-human spread of the highly pathogenic avian influenza H5N1 so far, the pathogen could evolve to infect humans more efficiently. Bird flu cases in cows had been unheard of till this year's outbreak. The first known cases of infected dairy cattle were observed in Texas in March; it has now grown to dairy herds in 12 states. According to United States Department of Agriculture (USA), 151 dairy cow herds have confirmed cases of avian influenza A(H5N1) virus infections in dairy cows as the number of infected herds continues to grow. Since 2022, USDA APHIS has reported HPAI A(H5N1) virus detections in more than 200 mammals in the USA. Human cases of bird flu are so far spread from poultry, live poultry markets, or dairy cattle so far. Symptoms of human bird flu begin within two to eight days of infection and at start may seem like common flu. Cough, fever, sore throat, muscle aches, headache and shortness of breath are other symptoms. As the condition turns worse, gut issues, breathing issues, or CNS changes are reported. What is bird flu? Bird flu, or avian flu, is an infectious viral disease that spreads among birds. In rare cases, it can affect humans. H5N1, H7N9, H5N6 and H5N8 strains of the virus have been spreading in recent years. Bird flu can spread to humans if they touch the infected birds or their droppings or bedding. It may also spread while killing or preparing infected poultry for cooking. Human bird flu infection cases rising in the US "Bird flu is spreading in cattle herds in the US in a surprising development. Scientists term the route of transmission as 'artificial' which means the cows are not passing it to one another through natural contact and it probably isn't transmitting in airborne particles from cow-to-cow," says Dr R S Mishra, Principal Director - Internal Medicine, Fortis Escorts, Okhla Road, New Delhi. The expert says the transmission is happening in milking parlours and it looks like it's through contaminated milking machinery. Dr Mishra says the US spread of bird flu has been driven in large part by migratory waterfowl and the knowledge about migratory patterns and intercontinental associations of waterfowl, as well as genetic analyses of viral strains support the hypothesis that the recombinant highly pathogenic avian influenza (HPAI) H5N8 entered North America from Asia via migratory birds. "Colorado has reported four confirmed infections of H5N1 bird flu virus in poultry workers, and is checking on the status of a fifth suspected case. The workers showed mild symptoms, from conjunctivitis, or pink-eye, to respiratory signs. Human infections with H5N1 avian flu could cause severe disease and even a pandemic if the virus were to change and acquire the ability to spread easily between people hence it is of extreme importance to monitor its spread," says Dr Tushar Tayal, Consultant, Internal Medicine, CK Birla Hospital, Gurugram. Precautions to follow to prevent bird flu Dr Mishra lists the following preventive measures that must be taken to avoid getting infected by the virus. 1. Proper sanitary measures must be implemented to prevent bird flu. This includes application of foot bath at the entry of the farms, washing of utensils and equipment after use at the farms. 2. One must wash their hands properly before and after various poultry-related work. 3. Avoid close contact with infected or suspected birds and animals, especially their droppings, saliva and other secretions. 4. Avoid consuming raw/uncooked/partially cooked poultry products such as chickens and eggs. Cooking for half-an-hour and 700C kills the bird flu virus. Symptoms of bird flu Symptoms of bird flu in humans include fever and cough, sore throat, muscle aches, conjunctivitis (eye infections), severe respiratory illnesses such as pneumonia. Complications of bird flu include pneumonia, organ failure, and acute respiratory distress syndrome (ARDS). Is vaccine the answer? Vaccination plays a crucial role in curbing diseases in both cattle and humans, particularly in the context of avian influenza outbreaks. Vaccinating against avian influenza can reduce transmission rates. Researchers are actively developing and testing vaccines for cattle, with promising candidates using mRNA technology and harmless DNA viruses to deliver genetic material. For humans, vaccination can protect individuals from getting ill and mitigate the risk of avian influenza viruses mixing with seasonal flu strains. This could prevent virus from being evolved to a more transmissible and dangerous forms. Countries like Finland and the United States are already vaccinating high-risk workers and stockpiling doses, emphasising the importance of preparedness. Additionally, advanced mRNA-based vaccines offer a rapid and adaptable response to emerging strains, enhancing the ability to manage potential pandemics effectively.

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Human bird flu cases rising in the US: Here's why; know symptoms and preventive tips - The Times of India

In spring 2022, a handful of red foxes in Wisconsin were behaving oddly. Veterinary pathologist Betsy Elsmo learned that a local wildlife rehabilitation center was caring for foxes with neurological symptoms like seizures, tremors, uncoordinated movements and lethargy.

But tests for common pathogens like canine distemper virus and rabies that typically cause the symptoms came back negative. Then a red fox kit tested positive for influenza A. This group of viruses includes seasonal flus that cause respiratory disease in people and many other strains that commonly circulate among animals such as waterfowl and other birds.

I was surprised, says Elsmo, of the University of WisconsinMadison. And to be honest, at first I kind of wrote it off.

That is, until a veterinary technician at the rehab center sent Elsmo a study describing cases of avian influenza in red foxes in the Netherlands. Examinations of the Wisconsin kits tissues under the microscope revealed lesions in the brain, lung and heart that matched what had been seen in the Netherlands animals. And I thought, I think it is [bird flu], she recalls.

Additional testing confirmed the diagnosis in the kit and the other foxes, Elsmo and colleagues reported in the December 2023 Emerging Infectious Diseases. The animals had contracted a lethal strain of H5N1 avian influenza that emerged in late 2020 in Europe and has since spread around the world. At the time infections were discovered in the Wisconsin red foxes, bird flu was expanding its incursion into North America.

Since H5N1 arrived on North American shores in December 2021, it has infected animals as wide-ranging as polar bears, skunks, sea lions, bottlenosed dolphins and cows (SN: 7/8/24). And one unwelcome revelation of the ongoing outbreak is the viruss propensity to invade the brains of myriad mammals.

H5N1 is now known to infect more than 50 mammal species. Scientists had documented bird flu cases in only about a dozen species during previous outbreaks.

Theres nothing particularly special about this strain that allows it to plague so many species, research suggests. Rather, because the strain has spread so far and wide among birds both wild and domesticated there are simply more opportunities for mammals to be exposed, says virologist Emmie de Wit of the National Institutes of Healths Rocky Mountain Laboratories in Hamilton, Mont. (SN: 1/25/24). For some mammals, infected birds may be on the menu. For others, their water or food might be contaminated with virus-laden bird excrement.

Water-loving birds are exposed to influenza A viruses so often that most have some form of immunity that can protect them from a serious case of H5N1. If the birds do exhibit symptoms, they are usually mild and respiratory or gastrointestinal in nature. But other birds that dont get infected as frequently, such as eagles, vultures and pelicans, can become severely ill and die.

In mammals, bird flu typically causes respiratory symptoms such as congestion or shortness of breath. Neurological symptoms such as seizures or paralysis are among the most striking and common signs that the virus has reached the brain. And once it does, the infection is often fatal. In the ongoing H5N1 outbreak, such cases have been confirmed posthumously in house cats, raccoons, sea lions, dolphins and several other species (SN: 5/31/24).

From a bottlenosed dolphin in Florida to a polar bear in Alaska, many mammals across the United States have tested positive for avian influenza since 2022. Click on a colored dot to find out what species the virus was detected in and the county in which the animals were found. Zoom in for a closer look.

H5N1 and its close relatives have an easier path to the brain compared with other flu strains, de Wit says. And the virus is exceptionally good at making copies of itself inside a variety of cells, including nerve cells.

To break inside a cell, flu viruses exploit a protein called sialic acid on the cells surface. Bird cells and mammalian cells in the upper airway typically have different types of sialic acids, which means that bird flu viruses dont easily infect mammals and vice versa.

But studies have shown that parts of the human brain, for instance, are covered in birdlike sialic acid proteins. Many cells, including the nerve cells in the olfactory bulb which is important for sense of smell and links directly to the brain also have additional proteins that allow H5 viruses to replicate. Both of those traits mean that theres a direct entry route [to the brain] from your nose, de Wit says. So avian flu viruses may pose a bigger threat to the brain than, say, seasonal influenzas that mostly target cells in the nose, throat and lungs.

Since 2003, there have been 891 cases of H5N1 in people, about half of which were fatal according to the World Health Organization. In the current outbreak, 15 people have been infected with the strain hitting mammals hard. Four people had severe disease two developed pneumonia and at least one died.

Symptoms in people can vary from mild to severe, and some individuals infected with avian influenza viruses during previous outbreaks have developed neurological symptoms. Such cases are rare, the agency says, although how often the virus makes it to the brain is unclear.

How often the virus invades the brains of other mammals is also unknown. Most countries dont regularly test healthy-looking wildlife for viral infections, so such cases likely represent only the sickest individuals, Elsmo says. Its possible that some infected animals never develop severe disease and therefore escape the notice of people.

Avian influenza viruses can affect other parts of the body as well. When you break it out by species, it seems like the pattern of tissues that are most affected are little bit different, Elsmo says.

For instance, foxes and raccoons seem to have severe brain lesions as well as lesions in the heart and lungs. Striped skunks, meanwhile, tend to have few brain lesions, some of which are mild compared with red foxes. Instead, at least in Elsmos experience, H5N1 seems to target the skunk livers and organs in the lymphoid system, which protects against infection and removes waste from the body.

Some animals that have been killed by H5N1 weirdly had signs of infection only in the brain. Flus a respiratory virus, says Richard Webby, a virologist at St. Jude Childrens Research Hospital in Memphis, Tenn. So [the respiratory system is] where it should be before anywhere else.

The brain of a red fox in the Netherlands, for instance, was infected with H5N1 but not the animals lungs. Red foxes and mink in Canada similarly had mostly neurological disease. And bird flu didnt seem to touch the lungs of a bottlenosed dolphin found off the coast of Florida in 2022, despite the animal having virus-infected brain tissue, Webby and colleagues reported April 18 in Communications Biology.

Its possible that the dolphin had cleared the respiratory infection before it died, but the team found no evidence of pulmonary disease. Nor do dolphins have a sense of smell, which eliminates the possibility that the virus could reach the brain through the nose.

Exactly how the virus might sometimes sidestep respiratory tissues and hitch a ride directly to the brain is unclear. One possibility is that H5N1 already has that ability. Maybe it was more common, but we just never had the numbers [of mammalian infections necessary] to see it, Webby says.

Or perhaps when a mammal like a red fox or a dolphin takes a bite out of an infected bird, viral particles in the meat gain a direct path to the brain via nerves lining the mouth and digestive tract.

Virologist and veterinarian Vctor Neira thinks thats what may be happening in some sea lions in Chile. He and colleagues investigated an outbreak in the animals in 2023 along the coast of Chile, including two animals that the team necropsied. Although one animal didnt have neurological symptoms, the other had paralysis, disorientation, lack of coordination and tremors, the researchers reported in October 2023 in Veterinary Quarterly. The virus had infected multiple organs including the lungs, liver and kidneys, but the highest viral counts came from the brain.

Because H5N1 hasnt been infecting sea lions for very long, since just 2023, there is still a lot to learn about how the virus affects the animals, says Neira, of the University of Chile in Santiago.

Just how many mammal species are susceptible to infection is an open question. Usually, scientists study influenza virus in swine, mice, humans and birds, Neira says. Different wild animals, even several domestic animals, have not been studied with this virus.

Theres an urgency to finding out. Thats because every infection gives the virus an opportunity to adapt in ways that could allow it to spread more readily among mammals, de Wit says. Some research suggests that the virus may be spreading from marine mammal to marine mammal in parts of South America. But so far, infections in other animals are largely dead ends, with no spread to other individuals. The risk to people remains low, although workers on poultry and cattle farms who work closely with animals are at a higher risk than the general public.

Still, we cannot stop paying attention, de Wit says. The ongoing outbreak serves as a reminder that viruses are versatile foes.

Excerpt from:

Bird flu has been invading the brains of mammals. Heres why - Science News Magazine

Scientists are raising the alarm about US cases of H5N1 in cows as transmission to humans is easier. Here in Europe, steps are being taken to prepare.

A strain of bird flu that jumped to dairy cows and then farmworkers in the US this spring could become a global health risk but the extent of the threat is unknown and officials in Europe and elsewhere could be caught unprepared if it escalates.

The US cases are the latest upswell of a highly pathogenic avian influenza (H5N1) that has been circulating among migratory birds and mammals in recent years, mostly in Europe and the Americas.

Since March, the strain has cropped up in 145 cattle herds in 12 US states and infected four dairy workers, all of whom went on to recover from their illnesses.

There has been no evidence of human-to-human spread, which is a key marker of pandemic threat, while no human cases of the strain have been reported in Europe, and the European Centre for Disease Prevention and Control (ECDC) says the general public is at low risk of infection.

Even so, experts say there are enough warning signs that European countries should already be monitoring the virus and getting ready to respond quickly if that changes.

Waiting until the virus emerges among people on this side of the Atlantic would allow H5N1 to spread unchecked for long enough that it becomes difficult, if not impossible, to quash.

Things can change very fast, and it's difficult to put a precise timeline on it, because it depends on what the emergence process looks like, Colin Russell, an evolutionary biologist at Amsterdam University Medical Center and chair of the European Scientific Working Group on Influenza and Other Respiratory Viruses (ESWI), told Euronews Health.

If we don't know what we're missing, we could already have a problem on our hands, Russell said.

The US outbreak has scientists worried as its the first time H5N1 has been documented in cattle, making it far riskier that the virus will spread to humans, and because H5N1 has been lethal in the past.

Between 2003 and 2024, H5N1 caused 889 illnesses and 463 deaths in 23 countries, a fatality rate of 52 per cent, according to the World Health Organization (WHO).

While the US strain doesnt yet have the mutations that enable rapid spread between people, researchers said this week that the inflection point could be closer than previously thought, after they found signs of transmission between small animals in lab tests.

Its a little bit concerning, because it means that the virus does have more ability than typical highly pathogenic avian influenza viruses to spread by air from mammal to mammal, Thijs Kuiken, professor of comparative pathology at the Erasmus University Medical Centre, told Euronews Health.

His research focuses on avian flu and other emerging viral diseases but he was not involved with the recent study.

Kuiken and other experts say the risk from H5N1 to people around the globe appears to only be moderately higher than before the US cattle outbreak, but that even a slightly elevated risk is enough to raise concerns.

The most likely [outcome] is that it will die off, rather than posing a significant change and enough changes to actually spread in other countries, Munir Iqbal, head of the avian influenza and Newcastle Disease group at the Pirbright Institute, told Euronews Health.

But in places where H5N1 is already present, the virus is unseen, and therefore everything [should be] treated like something infectious.

Some countries are taking their own steps to prepare for H5N1, regardless of whether the US dairy cattle strain poses the ultimate threat in Europe.

Finland, for example, is offering vaccines to 10,000 workers who are at high risk of coming into contact with bird flu, and is also monitoring fur farms for potential cases throughout the summer.

Meanwhile, German and Italian researchers have tested samples from cattle and goats in areas where the virus has circulated among birds in recent years, and found no evidence that they were infected.

Kuiken said several other European countries, including the Netherlands, Spain, Norway, Sweden, France, and Belgium, will soon launch their own studies.

When you all of a sudden realise that a species that you haven't been paying much attention to could have been infected, you want to look retrospectively to see whether it occurred, Kuiken said.

Looking into the future, many labs are now taking into account that they can't rule out the possibility that such unusual epidemiological events also will happen in Europe.

The European Commission is also stockpiling 665,000 doses of pre-pandemic vaccines, which help protect against flu strains with pandemic potential, and could buy another 40 million doses if needed.

The international vaccine consortium Coalition for Epidemic Preparedness Innovations (CEPI) is convening an expert group to support global access to H5N1 vaccines, if the situation escalates.

But for now, in Europe, surveillance of H5N1 is key, Dr Ruth Harvey, deputy director of the Worldwide Influenza Centre at the Francis Crick Institute, told Euronews Health.

We can do the risk assessments, and then we can react accordingly, Harvey said.

The US outbreak is not the only one on experts radars.

Cases of avian flu caused by different strains have been reported in India, China, Australia, and Mexico, where an infected person had no known exposure to animals and eventually died from their illness.

Russell said that beyond the dairy cattle crisis, all countries should be tracing animal pathogens for potential spillover into humans and setting up reporting infrastructure to share this information quickly with the international community.

There is an opportunity in this particular situation for there to be a call to arms for extra vigilance against these viruses globally, Russell said.

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How prepared is Europe to deal with the new threat of bird flu? - Euronews

DENVER (KDVR) Three presumptive positive cases of avian flu have been identified in workers at a commercial egg layer operation in Weld County.

So far, the three workers at the egg-laying farm have exhibited mild symptoms, including conjunctivitis and common respiratory infection symptoms. None of them have been hospitalized.

The Colorado Department of Public Health and Environment said the workers were culling poultry at a farm in northeast Colorado and said they suspect the cases were a result of working directly with infected poultry. The department also noted that the risk to members of the public is still low: All cases in humans have been after the infected individuals came in direct contact with infected animals.

One case of avian flu was identified in a man working at a northeastern Colorado dairy farm earlier this month. Officials said he exhibited only symptoms of pink eye, or conjunctivitis, and recovered from the infection, but also noted he had direct exposure to dairy cattle that were infected with avian flu.

Northeast Colorado is where the first case of highly pathogenicavian influenza in the state this year was detected on April 25, when dairy cattle were found to have highly pathogenic avian influenza. The outbreak has led to at least 10 facilities being placed in quarantine.

The infected egg-laying farm, which has about 1.8 million chickens, prompted Gov. Jared Polis to issue a disaster emergency declaration on July 5 for the H5N1 avian flu outbreak in Weld County. State health officials told FOX31s Matt Mauro that all of the birds would be culled to prevent the spread of the virus.

The bird-borne virus can be transmitted to cattle and humans but has also been found in other mammals. According to the World Health Organization, symptoms of the virus are primarily respiratory, but the most recent human case involved conjunctivitis (pink eye).

According to CDPHE, it is safe to drink pasteurized milk and eat properly handled and cooked dairy, beef, and poultry products, because the process kills bacteria and viruses, including avian flu.

The state health agency is also reminding Coloradans not to touch dead or sick animals, but if its unavoidable:

If you work with dairy cows that may have avian flu and start to feel ill, CDPHE encourages you to call 303-692-2700 during regular business hours, or 303-370-9395 outside of those hours. H5N1 must be reported to the Colorado Veterinarians Office. There is also an emergency rule enacted for mandatory testing of lactating dairy cattle moving interstate.

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3 Colorado workers at commercial egg facility presumed to have avian flu - FOX 31 Denver

(Photo by Jakob Cotton on Unsplash)

AMES, Iowa In a surprising twist of events, highly pathogenic avian influenza (HPAI) H5N1, a virus typically associated with birds, has made an unexpected leap to dairy cattle (cows) in the United States. This development, first detected in March 2024, has sent ripples through the scientific community and raised concerns about the viruss ability to adapt and spread to new species potentially threatening the health of humans and animals around the globe.

The H5N1 virus, part of the broader family of flu viruses, has long been a concern in the poultry industry and among wild bird populations. Its ability to cause severe disease and high mortality rates in birds has earned it the highly pathogenic designation. However, its recent appearance in dairy cows marks a significant shift in our understanding of the viruss capabilities.

Researchers from Iowa State University, led by Rahul Nelli and Todd Bell, conducted a study to understand how this avian virus could infect and replicate in mammals like cows. Their findings, published in the journal Emerging Infectious Diseases, shed light on the molecular mechanisms that allowed this cross-species jump.

At the heart of the matter are structures called sialic acid receptors. These receptors, found on the surface of cells, act like docking stations for viruses. Different types of sialic acid receptors exist, and traditionally, bird flu viruses prefer to bind to one type (2,3-linked), while human flu viruses favor another (2,6-linked).

The research team examined tissues from infected dairy cows and found that, surprisingly, their respiratory tracts and mammary glands contained both types of receptors. This dual presence potentially explains why these cows were susceptible to the avian flu virus.

Whats particularly concerning is the discovery that the virus could replicate in the cows mammary glands, leading to its presence in milk. This finding has triggered public health alerts and new testing requirements for dairy products, especially unpasteurized milk.

The infected cows showed signs of illness, including reduced milk production and unusual changes in milk consistency. Upon closer examination, researchers found evidence of the virus in both the lungs and mammary tissues of the affected animals.

This unexpected jump from birds to dairy cattle raises questions about the viruss ability to adapt and potentially infect other mammalian species, including humans. While theres no immediate cause for panic, the situation underscores the importance of ongoing surveillance and research in the field of zoonotic diseases those that can pass between animals and humans.

The discovery also highlights the interconnectedness of animal and human health, a concept known as One Health. As viruses continue to evolve and adapt, understanding these complex relationships becomes increasingly crucial for public health preparedness.

As research continues, scientists and health officials are working to develop strategies to monitor and contain the spread of this virus in dairy cattle populations. This event serves as a reminder of the ever-present potential for new infectious disease challenges and the need for continued vigilance and scientific inquiry.

Paper Summary

The researchers used a combination of microscopic examination and molecular techniques to study tissues from infected cows. They employed a method called lectin histochemistry, which uses plant proteins (lectins) that bind to specific types of sialic acid receptors.

By applying different lectins to tissue samples and observing where they bind, the team could map out the distribution of various receptor types in the cows respiratory tracts and mammary glands. They also used fluorescent labeling techniques to visualize the virus and receptors simultaneously under a microscope.

The study found that both types of sialic acid receptors (2,3-linked and 2,6-linked) were present in the respiratory tracts and mammary glands of the infected cows. The avian-type receptors (2,3-linked) were particularly abundant, which likely facilitated the initial infection.

The virus was detected in the epithelial cells lining the mammary glands and milk ducts, explaining its presence in milk. Interestingly, some immune cells (macrophages) also showed signs of infection, suggesting the virus could potentially affect the immune response.

The study was conducted on a small number of naturally infected cows, which limits the generalizability of the findings. The researchers didnt have the opportunity to study the progression of the infection over time or in experimentally controlled conditions. Additionally, while the presence of receptors explains the possibility of infection, it doesnt fully account for why this particular outbreak occurred now, suggesting other factors may be involved.

This research provides crucial insights into how an avian virus can adapt to infect mammals. The presence of both types of sialic acid receptors in cows suggests they could potentially be infected by both avian and mammalian influenza viruses, making them possible mixing vessels for new viral strains.

The study emphasizes the need for continued surveillance of influenza viruses in livestock and highlights the potential risks associated with unpasteurized dairy products. It also underscores the importance of a One Health approach, considering the health of humans, animals, and the environment as interconnected. Moving forward, more research is necessary to understand the full implications of this virus jump and to develop strategies to prevent and control such outbreaks in the future.

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Bird flu jumps to dairy cows, sparking fears of future pandemics - Study Finds

The virus has so far caused only minimal illness among humans, yet has spread rapidly among birds, sea mammals and other species with devastating effect.

Although U.S. health officers have repeatedly assured Americans that H5N1 bird flu poses little risk to their well-being, some experts have become increasingly critical of what they see as the governments failure to aggressively monitor the spread of virus among cattle and other farm animals. The virus has been reported in 145 dairy herds across 12 states, but critics say this is likely an underestimate.

They point to stories they have heard anecdotally from physicians and veterinarians in farming communities about mystery illnesses and cover-ups. And they point to perplexing hits of H5N1 in municipal wastewater far from any infected dairy herds.

I think our government officials are are not doing the thorough investigation they should be doing, said Rick Bright, a virologist and the former head of the U.S. Biomedical Advanced Research and Development Authority. I think they are continually minimizing this outbreak and this virus.

The worry among some experts is that H5N1-infected farm animals could serve as mixing vessels for new viral strains that could more easily infect people. They point to research released this week showing that the virus has receptors for both birds and humans. And they note that up to 75% of human infectious diseases are derived from pathogens that originated from animals.

Now, amid this heated debate over viral monitoring, a raw milk dairy farmer and longtime critic of the Food and Drug Administration has accused the government of ignoring his tip about a suspected H5N1 outbreak among a herd of dairy cows in early May.

Cows leave a dairy barn after milking.

(Tomas Ovalle / For The Times)

Although it remains unclear whether an outbreak actually occurred, neither federal nor state officials investigated the matter for weeks. Raw milk is not allowed to be sold across state lines, the FDA pointed out. In states that allow it, including New Mexico and California, regulation falls to state agencies. Only after inquiries by The Times did New Mexico officials look into the report. The state said the herd veterinarian did not find symptoms of H5N1 bird flu.

The delayed response, some experts say, suggests a disturbing lack of oversight on the part of government officials.

I think that once everybody decided it wasnt going to kill people and pasteurized milk and herds could get over it, then all that was left was to take these stopgap measures voluntary reporting, voluntary testing, testing when going across state lines that dont look anything like a really serious effort to go ahead and stamp it out, said Michael Payne, a researcher and outreach coordinator at the Western Institute for Food Safety and Security at UC Davis.

The outbreak claim comes from Mark McAfee, owner of Raw Farms, a raw milk dairy producer with herds in Fresno and Hanford. On June 17, McAfee who is also the president of the Raw Milk Institute, an advocacy group emailed the FDAs acting director, Donald Prater, to say that hed been told a raw milk dairy herd had been infected and that people had probably consumed the contaminated milk.

According to McAfees email, which was shared with The Times, a subset of a farmers cows were suffering yellowish, runny diarrhea; low milk production; thick, yellowish colostrum; and general weakness. The farmer told McAfee he had separated the sick cows about 10% of his herd and discontinued milking them.

Mark McAfee walks by cows feeding at his raw milk dairy.

(Tomas Ovalle / For The Times)

The farmer reported that for certain, humans had consumed the raw milk at some level, McAfee wrote to Prater, adding that the farmers veterinarian told the farmer to not report anything to anyone because the virus would pass and he did not want the FDA to swoop in and cause a media frenzy.

McAfee said he fields lots of questions and calls from raw milk farmers around the nation. Because hes president and founder of the Raw Milk Institute and the largest producer of raw milk in the country his advice and counsel is often sought by smaller dairy farmers.

Within 90 minutes of sending the email, Prater responded that he appreciated the time McAfee had taken to write the note and for sharing these perspectives. He then added that he and his agency would take note of the points you raised and come back to you if we have any questions.

According to McAfee, the FDA did not follow up with him. The state of New Mexico, where McAfee says the herd was infected, was made aware of the tip only last week, after the Times inquired.

The U.S. Department of Agriculture and the Centers for Disease Control and Prevention would not comment for the record on the matter, referring questions to the state.

Critics say whether the outbreak occurred or not, the lack of an immediate, or even timely, response underscores the absence of urgency and leadership in the face of a potential health threat.

If you turn your back on this virus, youre kind of inviting it in to bite you in the ass, said Bill Hanage, associate professor of epidemiology and co-director of the Center for Communicable Disease Dynamics at Harvard Universitys T.H. Chan School of Public Health.

Bright, the virologist, said the delay was a problem.

This is the stuff that drives me crazy, Bright said. I always tell people, its not necessarily the data that we have in front of us thats most concerning. It is whats being hid from us thats most concerning.

Farmers do not have to let government officials test their cattle, he said, which makes it hard to verify weeks after the fact whether an outbreak had occurred. If a dairy farmer allowed it, researchers could check for H5N1 antibodies in the blood.

I really dont think they want to know, he said of the U.S. government, and the FDA in particular.

The FDA disputes that. A spokeswoman said the agency has been in contact with the New Mexico Department of Agriculture, which is investigating, and hasnt been able to substantiate the claim that raw milk from an infected herd was sold to the public.

And to be sure, the FDA and McAfees Raw Milk Institute have had a long, contentious history.

To be quite frank, your source, Raw Milk Institute, are known advocates for repeatedly amplifying what they say is a lack of evidence that drinking raw milk with H5N1 is bad for you, said Janell Goodwin, an FDA spokeswoman.

The FDA position is that pasteurization makes the U.S. milk supply safe. It and other government agencies recommend that people do not drink raw milk.

McAfee, on the other hand, said he reported the outbreak because he believed it showed that unpasteurized, yet infected, raw milk was not a threat.

No one got sick from that outbreak, he insisted.

Mark McAfee, a raw milk dairy farmer and longtime critic of the FDA, has accused officials of ignoring his tip about a possible H5N1 outbreak among dairy cows.

(Tomas Ovalle / For The Times)

But epidemiologists The Times spoke with expressed skepticism on this point, suggesting that maybe nobody had reported being sick, noting that many dairy workers are migrants who may not relish a government visit. And they pointed to experimental and observational studies of barn cats that consumed H5N1 contaminated raw milk and had about a 50% mortality rate and really unpleasant symptoms, said Hanage, the Harvard professor.

Drinking raw milk is something that is a risk that we would rather people didnt take just for their own sake, he said.

McAfee noted that he has received a certificate of good standing by Californias Department of Food and Agriculture for voluntarily testing his cows milk for H5N1. A spokesman for the agency confirmed that as of July 1, the farms milk was clear of the virus.

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He reported a possible H5N1 outbreak in dairy cows. It took officials weeks to respond - Los Angeles Times

Three poultry workers tested positive for bird flu and more who showed symptoms of infection are being tested, state health officials announced Friday evening.

The outbreak of human cases, if confirmed, is the largest in the United States from the strain of bird flu also known as highly pathogenic avian influenza currently circulating across the globe.

The workers who tested positive were responding to an outbreak of bird flu at a commercial egg-laying operation in Weld County, where nearly 1.8 million chickens were being culled following the viruss discovery. None of the workers required hospitalization. Their symptoms ranged from pink eye to what the state described in a news release as common respiratory infection symptoms.

Samples taken from the workers tested positive at the state lab. They have now been sent to the federal Centers for Disease Control and Prevention for official confirmation.

The Colorado Department of Public Health and Environment wrote in a news release that additional samples from symptomatic workers will be tested over the weekend.

Before Friday, there had been only five known human cases of bird flu in the United States since 2022. One of those, the first discovered in the country from the current strain, was in a worker at a poultry farm in Montrose County in 2022. Another was identified last week in a dairy worker in Weld County. There have also been three other infections discovered in dairy workers in Texas and Michigan.

So far, every person infected in the United States has experienced mild symptoms and recovered with the help of antiviral medication.

Colorado has emerged as the epicenter of the bird flu epidemic in the United States. In addition to its at least five human cases, Colorado now has the nations worst outbreak of bird flu among dairy cattle.

State agriculture officials identified eight new infected dairy herds this week, bringing the states total number of cases in dairy cattle to 35 since April. That places Colorado first among states, seven cases ahead of Idaho, which like most other states with large numbers of outbreaks has a far larger dairy industry than Colorado. About a third of Colorados dairy herds have now been infected.

Bird flu, as the name indicates, typically circulates in birds, and it can be particularly devastating if it infects domestic poultry. But the current strain circulating the globe has distinguished itself by its ability to infect a wide variety of animals. Bears, mountain lions, seals, skunks, cats and more have all died from bird flu in recent years.

Humans have occasionally been infected by bird flu in the past with some strains carrying a high fatality rate but there has never been sustained person-to-person transmission of the virus. Instead, infections tend to occur following close contact with infected animals, which is what state health officials speculate occurred for the newest human outbreak in Weld County.

There has been no documented instance in the U.S. of person-to-person transmission from the current bird flu strain, and health officials believe the risk to the general public remains low.

Where we need to ramp up the level of concern in the population is when we see those workers get infected and spread it to their families, Elizabeth Carlton, an epidemiologist at the Colorado School of Public Health, told The Colorado Sun earlier this month.

Eating poultry, eggs or beef remains safe, so long as they are cooked to the appropriate temperature. Drinking milk is also safe, so long as it is pasteurized.

People who work with cows or poultry should be especially vigilant about hand-washing and other good-hygiene practices. If they start to feel sick, they should seek medical attention or call CDPHE at 303-692-2700 or 303-370-9395 after normal business hours.

Based on facts, either observed and verified directly by the reporter, or reported and verified from knowledgeable sources.

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Colorado identifies three new human cases of bird flu and more people are symptomatic - The Colorado Sun

The bird-flu virus H5N1 (purple; artificially coloured) infects a human cell.Credit: Steve Gschmeissner/Science Photo Library

As the H5N1 bird-flu virus spreads relentlessly in animals around the world, researchers seeking to understand how a human H5N1 pandemic might unfold have turned to a rich source of clues: data on the immune systems response to influenza.

Such information provides hints about who could be most vulnerable in an H5N1 pandemic. Previous research also suggests that, in a confrontation with the virus, our immune systems would not be starting from scratch thanks to previous infections with, and vaccinations against, other forms of flu. But this immunity is unlikely to prevent H5N1 from inflicting serious damage to global health, if a pandemic were to begin.

The H5N1 strain now running rampant began as a bird pathogen before branching out to mammals. Classified as a highly pathogenic virus for its lethality in birds, it has killed millions of domestic and wild birds around the world since it first emerged in 1996.1 It has also spread to a growing list of mammal species, including seals and foxes, and has caused more than 460 human deaths since 2003.

So far, the virus has not gained the ability to spread effectively between people, which has kept the potential for a pandemic at bay. But its repeated jumps from birds to mammals and evidence of transmission among mammals, such as elephant seals (Mirounga leonina)2, have alarmed researchers, who warn that the virus is gaining opportunities to become adept at spreading easily between people.

Bird flu in US cows: where will it end?

These worries were magnified when H5N1 was detected in March for the first time in US cattle animals that interact frequently with humans. As of 8 July, US health officials have confirmed bird-flu infections in nearly 140 dairy herds in 12 states and in 4 dairy farm workers.

All of the workers had mild symptoms, but scientists caution that the virus is still a threat. Its possible that the workers escaped severe illness because they might have caught H5N1 through exposure to milk from infected cows rather than the usual airborne particles, says Seema Lakdawala, an influenza virologist at Emory University School of Medicine in Atlanta, Georgia. Or perhaps its because the workers might have been infected through the eye rather than the typical route of the mouth or nose.

Malik Peiris, a virologist at the University of Hong Kong, says he is not surprised by these infections, nor reassured that mildness of these cases means that this virus is inherently mild.

The viruss inherent virulence isnt the only factor that would shape a pandemic, Peiris says. Another is the immune systems state of readiness.

Through a combination of past infection and immunization, by the time people reach adulthood, they have generally had considerable exposure to flu. Some estimates3 suggest that up to half of younger populations are infected annually with seasonal flu viruses, which cause regular waves of infections.

Flu and colds are back with a vengeance why now?

But exposure to seasonal flu offers limited protection against the new flu strains that could cause pandemics. These strains are genetically distinct from circulating seasonal strains, meaning that they face less built-up immunity in humans and can thus be more dangerous.

For now, H5N1 does not spread easily between people. But scientists worry that if it gains that ability, it could spark a pandemic, given that it is genetically different from seasonal flu viruses now in circulation. Tests of people across the United States found that few have antibodies against todays strain of H5N1. This implies that most of the population would be susceptible to infection from this virus if it were to start infecting people easily, according to the US Centers for Disease Control and Prevention, which ran the tests.

That doesnt leave people completely unprotected, because exposure to an older pandemic flu strain can defend against a newer one, says Michael Worobey, an evolutionary biologist at the University of Arizona in Tucson. For example, in a 2009 pandemic caused by the swine-flu virus H1N1, 80% of deaths were in people younger than 654. Older generations were spared owing to immunity stemming from exposure to different H1N1 strains when they were younger.

Exposure to H1N1 during the 2009 pandemic and at other times might, in turn, provide some protection against the H5N1 strain on the rise today. Both the H5N1 and H1N1 viruses have a surface protein designated N1, and an immune system that responds to H1N1 might also respond to H5N1. Peiris and his colleagues found that the near-universal exposure to H1N1 in 2009 and subsequent years produces antibodies that respond to H5N1 in nearly 97% of the samples they collected5. He is now running animal experiments to determine whether this antibody response confers protection against infection and serious illness.

Theres yet another complicating factor to the immune response to H5N1: a persons first bout of flu might have an outsized effect on their future immunity. In a 2016 paper6, Worobey and his colleagues analysed almost two decades worth of severe infections caused by two subtypes of bird flu, H5N1 and H7N9. They found that people are generally unscathed by the flu strain that best matches the one that had caused their first childhood flu infection whereas they are more vulnerable to mismatched strains.

How COVID-19 is changing the cold and flu season

Thus, people born before 1968 have tended to escape H5N1s ravages, because they probably had their first flu infection at a time when the dominant flu virus in circulation matched H5N1. But people born after 1968 eluded the worst of H7N9, because their first encounter with flu was probably with a virus that matched it rather than H5N1. Immunity from a first infection provided 75% protection against severe disease and 80% protection against death with a matching bird-flu virus, the authors found.

If an H5N1 outbreak were to occur, this first-bout effect predicts that older people could once again be largely spared whereas younger people could be more vulnerable, Worobey says. We should have that somewhere between the back and front of our minds, he says.

Read this article:

If bird flu sparks a human pandemic, your past immunity could help - Nature.com

Summary

What CDC knows

An outbreak of H5N1 bird flu among poultry and dairy cows continues to spread in the United States. Four human cases with exposures to sick cows have been reported.

What CDC is doing

CDC has issued updated guidance to help prevent the spread of flu, including from cattle to people, at livestock fairs or exhibitions across the country. CDC continues to respond to the public health challenge posed by the multistate outbreak of H5N1 bird flu in cows and other animals in the United States.

With agricultural and livestock fairs happening all around the country this summer and fall, the chances for people to be in close contact with pigs, poultry (e.g., chickens, turkeys, ducks, geese), and cattle increase. Livestock fairs and shows are an important learning opportunity for people of all ages interested in agriculture.

At the same time, animals exhibited at agricultural fairs and shows can carry and spread influenza A viruses that are different from the seasonal influenza A viruses that commonly spread among people.

As the multistate H5N1 bird flu outbreak in poultry, cows and other animals continues to spread, CDC is recommending that fair exhibitors take actions to help prevent the spread of influenza A viruses between animals and between animals and people.

Since the first report of H5N1 bird flu in U.S. dairy cows this March, four associated human cases have been detected. All four people had direct contact with sick cows before they got sick, had mild illness, and have recovered. These are the first reported instances of cow-to-human spread of H5N1 bird flu.

The number of dairy cow herds infected with H5N1 bird flu continues to grow. As of July 11, 146 dairy cow herds in 12 states have confirmed cases of A(H5N1) virus infections. CDC is working with the U.S. Department of Agriculture, the Food and Drug Administration, and state and local public health and animal health officials to respond to this public health challenge.

The risk of H5N1 bird flu to the general public is low at this time. People with close, prolonged, or unprotected exposures to infected birds or other animals (including livestock), or to environments contaminated by infected birds or other animals, are at greater risk of infection. Farm workers on affected farms, for instance, are at higher risk of infection than others in the population.

While rare, influenza A viruses can spread from animals (including pigs, poultry, and cattle) to people and also from people to animals. For example, swine influenza viruses spread commonly in pigs and avian influenza viruses spread commonly in wild birds and cause outbreaks in poultry and now cows. People can be infected by swine and avian influenza viruses and vice versa. People most often get infected with animal influenza A viruses after being in close contact with infected animals.

It is rare for people to get sick from these viruses, but when they do, the sickness has varied from mild to severe. In some cases, it has led to hospitalization or death.

Livestock exhibitors can take the following actions to help protect themselves, friends and family, other visitors, and livestock and prevent the spread of flu:

CDC has issued interim recommendations for preventing, monitoring and public health investigations of H5N1 bird flu in animals and people.

An appendix to CDCs interim H5N1 bird flu guidance categorizes the degree of risk by exposure.

In addition, USDA also has fair guidance that focuses on reducing the risk of influenza spread between animals.

Originally posted here:

CDC Issues Updated Guidance to Help Prevent Spread of Flu at Agricultural Fairs - CDC