bird flu

cats-suffer-h5n1-brain-infections,-blindness,-death-after-drinking-raw-milk

Cats suffer H5N1 brain infections, blindness, death after drinking raw milk

bird flu, Cats, cows, dairy cows, H5N1, health, herds, infectious diseases, influenza, milk, Science / /

Spillover —

Mammal-to-mammal transmission raises new concerns about the virus’s ability to spread.

–

Farm cats drinking from a trough of milk from cows that were just milked.

Enlarge / Farm cats drinking from a trough of milk from cows that were just milked.

On March 16, cows on a Texas dairy farm began showing symptoms of a mysterious illness now known to be H5N1 bird flu. Their symptoms were nondescript, but their milk production dramatically dropped and turned thick and creamy yellow. The next day, cats on the farm that had consumed some of the raw milk from the sick cows also became ill. While the cows would go on to largely recover, the cats weren’t so lucky. They developed depressed mental states, stiff body movements, loss of coordination, circling, copious discharge from their eyes and noses, and blindness. By March 20, over half of the farm’s 24 or so cats died from the flu.

In a study published today in the journal Emerging Infectious Diseases, researchers in Iowa, Texas, and Kansas found that the cats had H5N1 not just in their lungs but also in their brains, hearts, and eyes. The findings are similar to those seen in cats that were experimentally infected with H5N1, aka highly pathogenic avian influenza virus (HPAI). But, on the Texas dairy farm, they present an ominous warning of the potential for transmission of this dangerous and evolving virus.

The contaminated milk was the most likely source of the cat’s fatal infections, the study authors concluded. Although it can’t be entirely ruled out that the cats got sick from eating infected wild birds, the milk they drank from the sick cows was brimming with virus particles, and genetic data shows almost exact matches between the cows, their milk, and the cats. “Therefore, our findings suggest cross-species mammal-to-mammal transmission of HPAI H5N1 virus and raise new concerns regarding the potential for virus spread within mammal populations,” wrote the authors, who are veterinary researchers from Iowa, Texas, and Kansas.

The early outbreak data from the Texas farm suggests the virus is getting better and better at jumping to mammals, and data from elsewhere shows the virus is spreading widely in its newest host. On March 25, the US Department of Agriculture confirmed the presence of H5N1 in a dairy herd in Texas, marking the first time H5N1 had ever been known to cross over to cows. Since then, the USDA has tallied infections in at least 34 herds in nine states: Texas, Kansas, Michigan, New Mexico, Idaho, Ohio, South Dakota, North Carolina, and Colorado.

The Food and Drug Administration, meanwhile, has detected genetic traces of H5N1 in roughly 20 percent of commercial milk samples. While commercial milk is still considered safe—pasteurization is expected to destroy the virus and early testing by the FDA and other federal scientists confirms that expectation—the finding suggests yet wider spread of the virus among the country’s milk-producing cows.

Cows are only the latest addition to H5N1’s surprisingly broad host range. Amid a global outbreak over the past several years that has devastated wild bird populations and poultry farms, researchers have documented unexpected and often deadly outbreaks in mammals. Since 2022, the USDA has found H5N1 in over 200 mammals, from big cats in zoos to harbor seals, mountain lions, raccoons, skunks, squirrels, polar bears, black bears, foxes, and bottlenose dolphins.

“The recurring nature of global HPAI H5N1 virus outbreaks and detection of spillover events in a broad host range is concerning and suggests increasing virus adaptation in mammals,” the authors wrote. “Surveillance of HPAI viruses in domestic production animals, including cattle, is needed to elucidate influenza virus evolution and ecology and prevent cross-species transmission.”

In the meantime, it’s definitely not the time to start drinking raw cow’s milk. While drinking raw milk is always dangerous because it carries the threat of various nasty bacterial infections, H5N1 also appears to be infectious in raw milk. And, unlike other influenza viruses, H5N1 has the potential to infect organs beyond the lungs and respiratory tract, as seen in the cats. The authors of the new study note that a 2019 consumer survey found that 4.4 percent of adults in the US consumed raw milk more than once in the previous year, suggesting more public awareness of the dangers of raw milk is necessary.

Cats suffer H5N1 brain infections, blindness, death after drinking raw milk Read More »

20%-of-grocery-store-milk-has-traces-of-bird-flu,-suggesting-wider-outbreak

20% of grocery store milk has traces of bird flu, suggesting wider outbreak

bird flu, CDC, cows, fda, H5N1, health, Infectious disease, milk, Science, USDA, virus / /

widespread —

The milk is still considered safe, but disease experts are alarmed by the prevalence.

–

20% of grocery store milk has traces of bird flu, suggesting wider outbreak

The Food and Drug Administration reported late Thursday that about 20 percent of retail milk samples from around the country tested positive for genetic fragments of the bird flu, aka highly pathogenic avian influenza (HPAI) virus H5N1. While retail milk is still considered to be safe, the finding suggests that the spread of the virus in cows is more extensive than is currently known.

The FDA used a test called quantitative polymerase chain reaction (qPCR), which can only detect the presence of genetic fragments. In pasteurized retail milk, it is highly likely that those genetic snippets are merely remnants of virus particles destroyed during pasteurization. The FDA is currently conducting additional testing using egg inoculation tests, a gold standard for detecting a live virus, to confirm the effectiveness of pasteurization. Meanwhile, the director of the National Institute of Allergy and Infectious Diseases, Jeanne Marrazzo, told reporters Wednesday that tests at the agency’s federal labs so far did not identify live virus from any of its sampling. Additionally, several previous studies have found that pasteurization of eggs—which is done at a lower temperature than it is for milk—was effective at destroying H5N1.

While experts are largely unconcerned with the safety of commercial milk, the potential for wide, unrecognized spread of bird flu in dairy herds is alarming. To date, the US Department of Agriculture has only confirmed infections in 33 herds in eight states. The FDA acknowledged that of its positive samples, “a greater proportion of positive results [are] coming from milk in areas with infected herds.” But with tens of thousands of dairy herds in the US, the finding suggests that infections are being missed. It does not necessarily suggest that 20 percent of all cows are affected, since milk is pooled for commercial distribution. But 33 herds alone are unlikely to explain the high prevalence.

Last week, The New York Times reported that the one dairy herd that tested positive for bird flu in North Carolina did not show any symptoms of the infection. The possibility of asymptomatic spread of the virus among cows will make containment and monitoring far more difficult—and could explain why infections may be easily missed. On Wednesday, the USDA issued a federal order requiring dairy cattle to have a negative H5N1 test before being moved across state lines.

For now, the risk to the public is still considered low by the Centers for Disease Control and Prevention. But the more the bird flu virus spreads among mammals—and mammals with close contact with humans—the more opportunities it has to evolve to jump to and among people, experts warn.

20% of grocery store milk has traces of bird flu, suggesting wider outbreak Read More »

fragments-of-bird-flu-virus-genome-found-in-pasteurized-milk,-fda-says

Fragments of bird flu virus genome found in pasteurized milk, FDA says

avian influenza, bird flu, CDC, cows, dairy cows, fda, flu, H5N1, Infectious disease, influenza, milk, pasteurization, Science, Uncategorized / /

Milk testing —

The test cannot tell if the virus is live. The FDA still assess milk supply as safe.

–

Cows being milked

Enlarge / Cows being milked

The Food and Drug Administration on Tuesday announced that genetic fragments from the highly-pathogenic avian influenza virus H5N1 have been detected in the pasteurized, commercial milk supply. However, the testing completed so far—using quantitative polymerase chain reaction (qPCR)—only detects the presence of viral genetic material and cannot tell whether the genetic material is from live and infectious viral particles or merely remnants of dead ones killed by the pasteurization process.

Testing is now ongoing to see if viable, infectious H5N1 can be identified in milk samples.

So far, the FDA still believes that the milk supply is safe. “To date, we have seen nothing that would change our assessment that the commercial milk supply is safe,” the agency said in a lengthy explanation of the finding and ongoing testing.

H5N1 made its startling jump to US dairy cows recently, with the first ever documented cases in a Texas herd confirmed on March 25. It has spread widely since then with at least 32 herds in eight states now known to be infected. The unexpected spread to bovines has raised fears that the virus is evolving to infect mammals more efficiently, and so poses a heightened risk of spread to and among humans.

But amid the alarming outbreak among the country’s dairy herds, federal agencies have appeared confident that the virus poses little risk to no risk to the safety of the milk supply.

“At this time, there continues to be no concern that this circumstance poses a risk to consumer health, or that it affects the safety of the interstate commercial milk supply because products are pasteurized before entering the market” the FDA wrote in an FAQ published Friday. “Pasteurization has continually proven to inactivate bacteria and viruses, like influenza, in milk.”

In the announcement Tuesday, the FDA also highlighted that multiple studies have shown that the pasteurization process for eggs, which uses lower temperatures than what is used for milk, is effective at inactivating H5N1.

Nevertheless, the FDA, along with the Centers for Disease Control and Prevention and the US Department of Agriculture, have continued to investigate potential risks, including establishing whether pasteurization can inactivate this specific virus. The FDA noted in its announcement Tuesday that, while pasteurization is expected to kill the virus, pasteurization is “different than complete sterilization.”

As such, it carried out the qPCR tests, expecting it might find some genetic fragments in the pasteurized milk because virus has been detected in raw milk. “Based on available information, pasteurization is likely to inactivate the virus, however the process is not expected to remove the presence of viral particles,” the FDA explained. “Therefore, some of the samples collected have indicated the presence of HPAI [Highly Pathogenic Avian Influenza] using quantitative polymerase chain reaction (qPCR) testing.”

The FDA did not indicate how many samples it has tested, where the samples were collected from, or the level of viral genetic material the samples contained.

The agency is now working on assessing whether it can identify if any virus particles are infectious using egg inoculation tests, which are considered a gold-standard for determining viral viability. It added that it will release results from those tests and others in “the next few days to weeks.”

“[W]e take this current situation and the safety of the milk supply very seriously. We recognize the importance of releasing further, actionable information,” the FDA said.

Meanwhile, the agency reported that the CDC’s food safety group has been closely monitoring emergency department data and flu testing data for any unusual trends in flu-like illness, flu, or conjunctivitis, which could indicate spread of H5N1 to people. “To date, surveillance systems do not show any unusual trends or activity,” the FDA said.

Fragments of bird flu virus genome found in pasteurized milk, FDA says Read More »

concern-grows-as-bird-flu-spreads-further-in-us-cows:-32-herds-in-8-states

Concern grows as bird flu spreads further in US cows: 32 herds in 8 states

avian influenza, bird flu, CDC, cows, dairy cows, fda, H5N1, herds, infection, milk, outbreak, Science, USDA, virus / /

Rapidly evolving —

Experts say the US is not sharing as much data on the outbreak as it should.

–

Greylag geese sit on a field and rest while a cow passes by in the background.

Enlarge / Greylag geese sit on a field and rest while a cow passes by in the background.

Researchers around the world are growing more uneasy with the spread of highly pathogenic avian influenza (H5N1) in US dairy cows as the virus continues to make its way into new herds and states. Several experts say the US is not sharing enough information from the federal investigation into the unexpected and growing outbreak, including genetic information from isolated viruses.

To date, the US Department of Agriculture has tallied 32 affected herds in eight states: Idaho, Kansas, Michigan, New Mexico, North Carolina, Ohio, South Dakota, and Texas. In some cases, the movement of cattle between herds can explain the spread of the virus. But the USDA has not publicly clarified if all the herds are linked in a single outbreak chain or if there is evidence that the virus has spilled over to cows multiple times. Early infections in Texas were linked to dead wild birds (pigeons, blackbirds, and grackles) found on dairy farms. But the USDA reportedly indicated to Stat News that the infections do not appear to be all linked to the Texas cases.

Spread of the virus via cattle movements indicates that there is cow-to-cow transmission occurring, the USDA said. But it’s unclear how the virus is spreading between cows. Given that even the most symptomatic cows show few respiratory symptoms, the USDA speculates that the most likely way it is spreading is via contaminated milking equipment.

Adding to the uncertainty of the virus’s spread, The New York Times on Friday reported that the one herd found infected with H5N1 in North Carolina showed no symptoms of the virus. This raises the possibility that the virus could be silently spreading in unknown numbers of other asymptomatic herds and states. In its most recent FAQ document, the USDA encouraged testing for H5N1 if herds show clinical symptoms, such as lethargy, fever, low milk production, and loose stools. But the Times noted that the agency has begun reimbursing farms for testing asymptomatic cows.

Meanwhile, the USDA also reported that it has evidence that H5N1 from dairy farms has spread back into birds in nearby poultry farms, but how this is happening is also unknown.

Data gaps

All the uncertainty and widespread transmission raises concern about how the virus is evolving to infect mammals and whether it is heading for humans. Last week, the chief scientist for the World Health Organization, Jeremy Farrar, told reporters in Geneva that the spread of the virus in US dairy cows is an “enormous concern,” according to CNN.  “The great concern, of course, is that in doing so and infecting ducks and chickens—but now increasingly mammals—that that virus now evolves and develops the ability to infect humans. And then critically, the ability to go from human-to-human transmission.”

In particular, experts are wary that the dairy cow outbreaks could spill over to nearby pig farms as it’s doing with nearby poultry farms. Pigs can be infected with both bird flu viruses and human flu viruses, making them potential melting pots for new recombinant flu strains.

So far, the USDA says that genetic sequences of H5N1 viruses infecting cows has not revealed any mutations that “would make it more transmissible to humans and between people.” But last Thursday, Stat reported that international experts have faulted the USDA for not sharing more genetic data from its investigation, among other information. Until this weekend, the agency had only shared a few genetic sequences in an international database of viral genome sequences (GISAID).

“A country with capacity like the United States should be able to generate this information within days,” Marion Koopmans, head of the department of viroscience at Erasmus Medical Center in the Dutch city of Rotterdam told Stat last week. “I would expect very fast, very transparent updates, and it’s somewhat amazing not to see that happening.”

On Sunday, facing mounting criticism, the USDA announced the release of 239 genetic sequences to GISAID. It noted it is also adding raw data to a US federal database “in the interest of public transparency and ensuring the scientific community has access to this information as quickly as possible.” The agency said it will continue to make such data available on a rolling basis.

Dr. Rosemary Sifford, the USDA’s chief veterinarian, told the Times, “Please recall that we’ve been engaged in this for less than a month. We are working very hard to generate more information,” she said.

Overall, the USDA and the US Centers for Disease Control and Prevention continue to consider the risk to the public to be low. Farmworkers and others who have direct contact with infected animals are encouraged to take precautions, however.

While deadly to birds, H5N1 in cows is relatively mild, rarely if ever causing deaths. Milk from sick animals contains high levels of virus, but it is being destroyed. Even if some infected milk makes its way into the milk supply, the Food and Drug Administration is confident that the virus would be killed in the pasteurization process. “Pasteurization has continually proven to inactivate bacteria and viruses, like influenza, in milk,” the agency said in an FAQ Friday. Some experts have called for data confirming this, though.

Concern grows as bird flu spreads further in US cows: 32 herds in 8 states Read More »

bird-flu-flare:-cattle-in-5-states-now-positive-as-texas-egg-farm-shuts-down

Bird flu flare: Cattle in 5 states now positive as Texas egg farm shuts down

bird flu, CDC, Chickens, dairy cows, eggs, health, hens, Highly pathogenic avian influenza, influenza, Science, USDA / /

flare-up —

The risk to the general public remains low, federal officials say.

–

Chicken eggs are disposed of at a quarantined farm with bird flu in Israel's northern village of Margaliot on January 3, 2022.

Enlarge / Chicken eggs are disposed of at a quarantined farm with bird flu in Israel’s northern village of Margaliot on January 3, 2022.

The flare-up of highly pathogenic bird flu continues to widen in US livestock after federal officials confirmed last week that the virus has spread to US cows for the first time. The virus has now been detected in dairy cows in at least five states, a single person in Texas exposed to infected cows, and an egg farm in Texas, all spurring yet more intense monitoring and biosecurity vigilance as the situation continues to evolve.

As of Tuesday, seven dairy herds in Texas, two in Kansas, and one each in Idaho, Michigan, and New Mexico had tested positive for the virus. The affected dairy herd in Michigan had recently received cows from one of the infected herds in Texas. It remains unclear if there is cow-to-cow transmission of the flu virus.

The virus—a highly pathogenic H5N1 avian influenza or HPAI—has been devastating wild birds worldwide for the past several years. Throughout the devastating outbreak, the flu virus has spilled over to various species, including big cats in zoos, river otters, bears, dolphins, seals, squirrels, and foxes. While cows were an unexpected addition to the list, federal officials noted last week that affected dairy farms had found dead wild birds on their farms, suggesting that wild birds introduced the virus to the cows, not an intermediate host.

On Monday, the Centers for Disease Control and Protection reported that a person in Texas who had contact with infected dairy cows had tested positive for the HPAI. The person’s only symptom was eye redness. The CDC said the person was treated with an antiviral for flu and was recovering. It is the second case of HPAI found in a person in the US. The first case was in a person in Colorado who was directly exposed to poultry infected with the virus. In that case, the person’s only symptom was fatigue over a few days. The person recovered. The CDC considers the risk of HPAI to the general public to be low.

Low risk

Meanwhile, the virus continues to spread to less-surprising animals: chickens. On Tuesday, Cal-Maine Foods, Inc., the country’s largest producer of fresh eggs, reported that HPAI was detected in one of its facilities in Texas. The facility is located in Parmer County, which sits at the border of Texas and New Mexico. It’s unclear if the egg facility is close to any of the affected dairy herds. Cal-Maine, following the US Department of Agriculture biosecurity protocols, immediately shut down the facility. Approximately 1.6 million hens and 337,000 pullets—young hens—were culled. Cal-Maine said the hens represented about 3.6 percent of the company’s total flock.

Since the outbreak began in wild birds, the virus has led to the deaths of over 82 million commercial and backyard birds in the US, with 48 states affected and over 1,000 outbreaks reported. The infections have spurred increases in egg and poultry prices.

It’s unclear if the virus will have the same effect on milk or beef, but so far, it appears that it will not. In the infected herds, the virus appears to only be affecting a small percentage of animals, particularly older animals, and they generally recover. As the USDA puts it there’s “little to no associated mortality reported.” Milk from sick cows is always diverted from the milk supply, but even if milk contaminated with HPAI were to make it into the supply, the virus would be destroyed in the pasteurization process.

Still, the continued, widespread outbreak and spillovers of HPAI in various species highlight the ever-present risk that influenza viruses could mix together, combining genetic fragments of different strains (genetic reassortment) to create a new strain that could spark outbreaks or even a pandemic in humans. In the current outbreak among dairy cattle, federal researchers were quick to check the genetic sequence of the HPAI, finding that, so far, the strain lacks mutations in key genetic regions that would signal the virus has become more infectious to humans. For now, the USDA and the CDC report that the risk to the public is low.

Bird flu flare: Cattle in 5 states now positive as Texas egg farm shuts down Read More »

cows-in-texas-and-kansas-test-positive-for-highly-pathogenic-bird-flu

Cows in Texas and Kansas test positive for highly pathogenic bird flu

avian influenza, bird flu, cows, dairy cows, H5N1, health, kansas, milk, Science, texas, USDA / /

viral spread —

The risk to the public is low, and the milk supply is safe.

–

Image of cows

Wild migratory birds likely spread a deadly strain of bird flu to dairy cows in Texas and Kansas, state and federal officials announced this week.

It is believed to be the first time the virus, a highly pathogenic avian influenza (HPAI), has been found in cows in the US. Last week, officials in Minnesota confirmed finding an HPAI case in a young goat, marking the first time the virus has been found in a domestic ruminant in the US.

According to the Associated Press, officials with the Texas Animal Health Commission confirmed the flu virus is the Type A H5N1 strain, which has been ravaging bird populations around the globe for several years. The explosive, ongoing spread of the virus has led to many spillover events into mammals, making epidemiologists anxious that the virus could adapt to spread widely in humans.

For now, the risk to the public is low. According to a release from the US Department of Agriculture (USDA), genetic testing by the National Veterinary Services Laboratories indicated that H5N1 strain that spread to the cows doesn’t appear to contain any mutations that would make it more transmissible to humans. Though the flu strain was found in some milk samples from the infected cows, the USDA emphasized that all the milk from affected animals is being diverted and destroyed. Dairy farms are required to send only milk from healthy animals to be processed for human consumption. Still, even if some flu-contaminated milk was processed for human consumption, the standard pasteurization process inactivates viruses, including influenza, as well as bacteria.

So far, officials believe the virus is primarily affecting older cows. The virus was detected in milk from sick cows on two farms in Kansas and one in Texas, as well as in a throat swab from a cow on a second Texas farm. The USDA noted that farmers have found dead birds on their properties, indicating exposure to infected birds. Sick cows have also been reported in New Mexico. Symptoms of the bird flu in cows appear to include decreased milk production and low appetite.

But so far, the USDA believes the spread of H5N1 will not significantly affect milk production or the herds. Milk loss has been limited; only about 10 percent of affected herds have shown signs of the infection, and there has been “little to no associated mortality.” The USDA suggested it will remain vigilant, calling the infections a “rapidly evolving situation.”

While federal and state officials continue to track the virus, Texas officials aim to assure consumers. “There is no threat to the public and there will be no supply shortages,” Texas Agriculture Commissioner Sid Miller said in a statement. “No contaminated milk is known to have entered the food chain; it has all been dumped. In the rare event that some affected milk enters the food chain, the pasteurization process will kill the virus.”

Cows in Texas and Kansas test positive for highly pathogenic bird flu Read More »