Category: Flu Virus

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Today we have a timely bonus episode to bring you up to speed about something you might have seen in the news bird flu.

To explain whats going on we invited Brown University professor Jennifer Nuzzo to the show. Jennifer is a professor of epidemiology and the director of the Pandemic Center at Brown University.

Megan Hall 00:25

Jennifer Nuzzo Thank you so much for coming in today.

Jennifer Nuzzo 00:28

Thanks for having me.

Megan Hall 00:29

So let's just get to the basics. First, what is bird flu.

Jennifer Nuzzo 00:33

So bird flu is a type of influenza virus that has been mostly affecting birds and other wildlife, it's been on our radar for more than 20 years, there have been some human cases that have occurred over that time. But these, by and large, have occurred in people who have had contact with infected animals. So there are the sporadic infections, there have been almost 900 over this 20 year period. So not a small number, but not anything like we see with seasonal influenza.

Megan Hall 01:06

Okay, so why are we hearing about bird flu in the news right now?

Jennifer Nuzzo 01:10

Yeah, so it's been a virus that we've been watching and worrying about for 20 years. But it's kind of come back into the news in the last year or so in part, because in the last year, we've seen a really rapid expansion in terms of where on the globe, we're finding this virus, and also a rapid expansion in terms of the number of animal species that are affected by this virus. So as I said, it's largely been a virus that has affected birds. But over the last year, we have seen the virus be capable of infecting many more animal species, including mammals. And once we start seeing this virus show up in mammals that increases our worries that it might be getting better capable of infecting mammals and humans or a mammal, So that's one reason why we worry about it.

And recently, you've heard about this virus in the news, because we found the virus in cows, that was surprise number one, we hadn't previously seen this virus in cows before. And a dairy worker, someone who was exposed to a dairy cow also was determined to have been infected by the virus. And so seeing a human being who has close contact with an infected cow, that increased worries one because, you know, again, we don't want people getting this virus, but two it just raises concerns that if we let this virus continue to circulate around the world, it could get better capable of infecting humans.

Megan Hall 02:30

So can you help put this into perspective for me? Because there's always the struggle to balance keeping people informed with wanting to avoid alarming people. So, where would you say bird flu is right now on a scale of like, common flu to COVID, 19 in 2020? Like, where are we at?

Jennifer Nuzzo 02:47

Yeah, so we're nowhere near either of those. When you hear sort of experts worrying about this virus, what you're hearing is worrying about a future scenario that hasn't yet happened, and wanting to make sure that we take action to prevent that future scenario from happening. Now, this virus does present a threat today. But right now that threat is to the people who have exposure to infected animals. And I do very much worry about farm workers and people who are exposed to raw milk because we have found the virus and raw milk, I worry about needing to protect them. But I don't worry right now for the general public that isn't regularly in contact with animals that are likely to be infected.

Megan Hall 03:28

What do we know about bird flu in milk? Do people need to be worried about drinking milk?

Jennifer Nuzzo 03:32

So short answer no. About a week or so ago, there was a headline that they had found evidence of genetic material in milk that had been pasteurized. And that's not really surprising, because if you know that the virus is in raw milk, and it had been found in raw milk from the infected dairy cows, what pasteurization does is it basically heats the milk, it doesn't remove the genetic material of the virus, but it makes the virus inactive so that it can't infect us. So follow up testing of the pasteurized milk was not able to grow virus from it. So that gives us good confidence that pasteurized milk cannot hurt people. Public health experts have long advised against consuming raw milk. And this is just another reason not to consume raw milk.

Megan Hall 04:19

So if you think it's really trendy and you want to drink raw milk, this is not the time to start.

Jennifer Nuzzo 04:24

Correct.

Megan Hall 04:26

What do we know about how this is spread?

Jennifer Nuzzo 04:29

Yeah, so that's been a little bit of a mystery. And it's still a mystery. It is currently thought that there was probably one introduction to dairy cows, but there's a little bit of uncertainty around that. And then it has spread to cows in other states, don't fully understand how that happened, though there is some thought that the movement of cows has played a role. I would say, I'm not terribly satisfied with the answers that have been given, and, you know, I don't think the movement of cows fully explains it, or at least I haven't seen compelling evidence that that's it. So I basically think that there's a lot more to learn. And what has been challenging is that we know that surveillance for this virus in cows is just woefully inadequate. You know, there's deep disincentives to test these animals. And also the testing that's been done so far is really been oriented around protecting the industry rather than trying to protect the humans who may be exposed to the virus.

Megan Hall 05:27

We learned so much about how viruses are spread with COVID. And we eventually learned that you know, it's in the air. So the best way to protect yourself is through masks. But do we know if you know, a cow was next to a bird that was infected? I mean, how did it get from the bird to the cow, or we have no idea.

Jennifer Nuzzo 05:44

So we don't know, we don't know that. We don't know how it spread from cow to cow, though we do believe that there's been cow to cow transmission. We don't know if it's been through milking operations, that somehow there might be a contamination or an aerosolization of the virus. also, the movement of cows between states may have played a role. But really, I think it's not clear enough to understand. In the worker who was infected, the infection was mild, it was conjunctivitis so an eye infection. And some people have raised the possibility that that may have been, you know, maybe touched raw milk and touched eye, we don't fully know. But you know, there is the worry that, you know, more serious infections can occur, because of the nearly 900 people who have been infected with this virus so far, again, over the last 20 years, about half have died. So this is not an historically mild virus. And so while it's, you know, better that this case that we found recently was mild, we can't say that future cases will be.

Megan Hall 06:45

So what is the government doing to respond to this and prevent the spread?

Jennifer Nuzzo 06:50

So the biggest change that we've seen so far is that the USDA, the US Department of Agriculture has changed its policy for testing cows. They've implemented a policy that some people are calling Test To Move, meaning that they are now requiring that cows that are going to move between states have to be tested. So that's a new requirement. And there's also a requirement that the test results will be reported to the USDA. That is an improvement because before and still largely, testing is pretty much voluntary, and it's otherwise restricted to cows with symptoms.

We know from data from North Carolina, that cows without symptoms may also be infected, they can test positive. So there's a number of ways why this new policy while, somewhat of an improvement is not adequate to figure out where in the country the virus is and where it isn't. But also not adequate to protect farmworkers. Because if you're only testing a cow with symptoms right before it is going to move between states and you have to send that specimen out to a laboratory. It's going to be some time before you get that test results. And what that means is by the time you find out that that cows been infected, it's very likely that a worker has been exposed to it.

Megan Hall 08:03

So if you were in charge, how would you be responding?

Jennifer Nuzzo 08:07

Well, I think one of the things we need is tests that can be done on the farm. So we get test results more quickly, so that we can perform tests much more frequently. And that we can perform them for the purposes of making sure a cows not sick before someone has exposure to them, or to encourage those who are likely to be around these cows to make sure they have personal protective equipment on. The other thing is to think about protecting farm workers more directly. The US government has undertaken some effort to develop and stockpile H5N1 vaccines.

Megan Hall 08:39

And H5N1 is the technical term for this bird flu.

Jennifer Nuzzo 08:43

Yeah, so that's, that's the name that we are giving this virus. The government has vaccines for this, its not quite ready for human use. They are keeping these vaccines in case the virus does become capable of spreading between people more easily, and so that we could, you know, potentially start vaccinating earlier than, if you remember, back in COVID, it was about a year before vaccines became available. This effort that's gone on will make it faster to get vaccines out. But in my view, we should be thinking about using these vaccines now to protect farmworkers that we know have been exposed to what has been historically a deadly virus.

Megan Hall 09:20

The last time we spoke was in 2022. And you were just coming to Brown to set up this pandemic center. How does the mission of your center fit into responding to something like a bird flu? Like this seems like sort of your work in action?

Jennifer Nuzzo 09:36

Yes, it is. And I think when we talked, we talked about why COVID-19 was not going to be our last pandemic threat, why the conditions of the world were such that we're gonna keep seeing these new viruses emerge and potentially threaten us. And that the goal for preparing for them would be that we would have the tools and policies and practices that we need, so that when they do occur, we could respond quickly, we could respond effectively, such that we kind of take off the table, the ability of these pathogens to upend our lives in the way that COVID-19 was capable of doing. And so, you know, I think, with the ending of COVID-19 as a kind of global emergency, I think many people were tempted to think that we were sort of done. That the worst was behind us and we really didn't have to worry about these scenarios anymore.

Since I've gotten to Brown there have been a number of different things that have occurred since the pathogen so we had a historically significant epidemic of another virus, respiratory syncytial virus that really, you know, overwhelmed a number of hospitals around the country. We had a very rapid and vigorous flu season that happened. We had a pretty unprecedented global epidemic of M-pox, a virus formerly called Monkeypox. This H5N1 is also concerning and yet another one of these infectious disease threats that we have to think about and respond to. So, it's just part of the operating conditions of our lives. We live in an age of pandemic threats, we're going to keep seeing new events occur, that make us worried that another pandemic could happen, and we need to be ready to respond quickly, so that we don't allow the worst to happen.

Megan Hall 11:16

So instead of seeing these pathogens as sort of the specter of another COVID, we kind of have to see it as business as usual. Like they're just gonna keep coming.

Jennifer Nuzzo 11:25

Yeah, I mean, I think of them sort of as recurring hazards. Just like if you live in, you know, the southern coastal states, you'd be regularly thinking about getting ready for a hurricane. If you live in the western states, you worry about wildfires, you know, there are recurring hazards, that we get ready for, that we plan for so that when they happen, we don't let them just completely consume us, that we can work to protect ourselves and to prevent the worst from happening.

Megan Hall 11:53

Great. Well, we're gonna wrap up, but before we leave, I just want to get sort of a takeaway from you, for our listeners who are trying to kind of weigh how worried they should be. What's your kind of final message to people as they're learning about this latest version of bird flu?

Jennifer Nuzzo 12:08

Yeah, so what I tell people is if you're not someone who has exposure to animals that are likely to be infected, this is not something you have to put on your worry list. However, when you hear people talking about it publicly, they're talking about it publicly because we want the government and other partners to take action to prevent this from becoming a bigger threat. I have been worrying about this virus for 20 years, I have worried that this virus could cause a pandemic for 20 years. It hasn't happened yet. That doesn't mean it won't just because it hasn't happened doesn't mean it won't happen. But what it means is that we have to get ready so that we could take off the table worry about this virus for good.

Megan Hall 12:46

Great. Well, Jennifer Nuzzo. Thank you for coming in today.

Jennifer Nuzzo 12:49

Thanks so much for having me.

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Humans in Public Health: H5N1 Bird Flu | School of Public Health | Brown University - Brown University

Food and Drug Administration Commissioner Robert Califf warned lawmakers Wednesday that unless the United States initiates countermeasures to stem the spread of avian influenza, the government may be ill-prepared to respond if the virus mutates and spreads among humans.

While the risk to the general public remains low, he told Senate appropriators in charge of FDA funding that investment to clamp down on the spread of the virus among cattle and poultry would pay dividends. That includes providing protective equipment to dairy workers, conducting research to understand how the virus is evolving and maintaining funding for vaccine manufacturing to be able to ramp up production quickly if needed.

If we institute the countermeasures now and reduce the spread of the virus now, then were much less likely to see a mutation that jumps to humans for which we are ill-prepared, Califf said.

The FDA is seeking an additional $157 million in federal funding in its fiscal 2025 budget request compared with fiscal 2023. Combined with user fees, the agency seeks $7.2 billion.

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FDA chief: Countermeasures against bird flu should be taken now - E&E News by POLITICO

We dont yet know if H5N1 bird flu will spill over from animals to infect a large number of humans. Based on the few cases of transmission so far, the World Health Organization has expressed concerns that infection in humans can cause severe disease with a high mortality rate.

But already it has wrought devastation upon so many lives. The deaths of millions of birds and mammals around the globe in the last few years directly and indirectly from this outbreak should be enough to spur urgent action to stop the spread of the virus, as well as remind us of the role humans play in the proliferation of infectious diseases.

Its my belief that humans have an obligation to the nonhuman life we share this planet with to mitigate the harm weve enabled this virus to cause. Our unsustainable activities factory farming, climate-warming emissions and habitat destruction, to name a few have helped turn bird flu from a natural phenomenon into an anthropogenic disaster. But even if you dont share that conviction, it is still in our best interest to keep this virus from spreading.

Disease has always been part of avian natural history. Wild birds are routinely exposed to mild viruses, but are seldom killed by them. Humans, however, have introduced factors that favor disease: A warming climate can weaken avian immune systems, and infections spread more easily when birds come into more frequent contact while sharing what little habitat remains.

And factory farming makes things even worse. When farm animals are kept in large numbers and close quarters in poultry and dairy farms, viruses can spread and mutate more easily. Its a human-facilitated training ground for diseases. The progenitor of todays H5N1 strain, for example, emerged in 1996 when a virus infecting farmed geese in Guangdong Province in southern China spilled back into wild populations.

Maintaining the health of their animal holdings and their businesses not to mention the potential risk to farm workers and the ever-present threat of human spillover requires farmers to act quickly. And when bird flu hits farms, often the only real way to contain it is the precautionary culling of entire flocks, which has resulted in tens of millions of dead hens since 2022. The United States Department of Agriculture recommends that farms use killing methods that avoid suffering. But as many as 66 million chickens and turkeys have been culled with a technique that animal welfare groups call unnecessarily cruel: ventilation shutdown, which kills over several hours through overheating.

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Opinion | H5N1 Already Killed Millions of Birds. Humans Share the Blame. - The New York Times

As bird flu continues to spread among dairy cattle herds in nine U.S. states, the federal government is providing $200 million to help stem transmission, Reuters reported on Friday. The Centers for Disease Control and Prevention has also asked states to prepare for more bird flu cases. On Monday, the agency requested that states provide personal protective equipment (PPE) to dairy farm workers who might be at risk, according to an emailed statement. Previously, the CDC had asked states to gear up to test at-risk people for the virus, Reuters reported, and now the federal funding will provide each affected farm with up to $28,000 a day toward measures to slow the spread among animals and prevent transmission to humans. Health agencies will also get $101 million for continued food safety monitoring. But U.S. officials have consistently assured Americans that the risk to the general public remains low.

So far the only person to be infected is a dairy worker who contracted bird flu in Texas, where the virus has been spreading among cattle. The worker tested positive after developing pink eye, which was their only symptom, according to a New England Journal of Medicine (NEJM) report published on May 3. Dairy cattle herds have also been infected in Colorado, Idaho, Kansas, Michigan, New Mexico, North Carolina, Ohio and South Dakota. Bird flu hasnt spread to any other people so far, but it has been detected in wild birds, including several geese, in New York City parks and green spaces, according to a new study, and there are renewed fears about other mammals being infected.

How concerned should you be about bird flu, and what might this mean for the food supply? Heres what you need to know.

Bird flu clinically known as influenza A (H5N1) is a variation of flu virus that spreads primarily among birds and poultry and can be highly contagious and even fatal among birds, according to the CDC. Occasionally, the virus will jump to other animals if they eat infected birds or drink water contaminated by the feces of infected birds, the CDC says. That has become more common in recent years. Viruses are constantly mutating, and the more they spread, the more they mutate. A recent family of variants may be particularly adept at infecting other animals, including cattle, according to the World Health Organization.

Its rare for the virus to infect humans, and when it does happen, its usually confined to one person who was in close contact with an infected animal and doesnt spread to others. Bird flu may cause mild to severe sickness in humans, and it has the potential to cause pneumonia and severe, sometimes fatal lung inflammation. Since 2020, there have been 26 cases in humans confirmed by the WHO, seven of which have been fatal.

The CDC continues to call for calm and considers the risk to the general public low, but, on April 5, the agency requested that state health departments begin gearing up in case additional people are infected.

So far the U.S. Department of Agriculture (USDA) has confirmed that there are 12 infected dairy cattle herds in Texas, 10 in Michigan, four in Kansas, eight in New Mexico, three in Idaho, two in Colorado and one each in North Carolina, Ohio and South Dakota. Cases in birds in New York City parks and green spaces have also been confirmed by Icahn School of Medicine at Mount Sinai researchers.

The infected person in Texas was diagnosed after developing conjunctivitis, or pink eye. Its only the second-ever human case of bird flu in the U.S.; the first was a poultry farmworker who was infected in 2022 while culling infected birds and recovered after experiencing only mild fatigue. Eye inflammation was the only symptom the Texas dairy worker experienced; they never developed any respiratory symptoms that health officials might have expected with bird flu, according to the NEJM report.

Other dairy and poultry farmworkers are the CDC's main concern now. On May 6, the agency asked state health and agriculture departments to provide PPE to dairy farm workers at risk of contracting bird flu in an effort to prevent any additional cases, the agency said in an emailed statement. So far, the CDC has tested at least 30 people for bird flu and monitored at least 220 for symptoms. The agency has also asked state health officials to take other steps like making sure they have bird flu tests available to confirm possible infections. It also said health officials should stay in close contact with veterinarians and agriculture department officials and asked to be notified of any "challenges" states encounter.

While farmworkers are at the greatest risk because of their close and frequent proximity to potentially infected animals, the Icahn School of Medicine study authors warned that it's not impossible for city dwellers to be exposed. "Our work highlights that the interface between animals and humans that may give rise to zoonotic infections" germs that spread between animals and people "or even pandemics is not limited to rural environments and commercial poultry operations but extends into the heart of our urban centers," the researchers wrote.

For the general public, the risk remains low, the CDC says. Bird flu has never been very good at spreading from person to person, so its unlikely to become widespread. The virus would have to mutate in some specific, key ways to make that possible. The good news is that it hasnt, according to preliminary testing of a sample of virus from the infected person, who has only mild symptoms.

After particles of the bird flu virus were discovered in about 1 in 5 samples of grocery store milk, further Food and Drug Administration testing has confirmed that the virus was inactivated by pasteurization, a sterilizing process used on more than 99% of the commercial milk supply. The U.S. Department of Agriculture also tested ground beef for bird flu, and all the samples came back negative.

Bird flu has also been found in unpasteurized milk, but you shouldnt consume unpasteurized milk or cheese regardless, the CDC warns, because they carry risk of infections like listeria. The CDC also says that the risk of being infected from eating eggs is low, and properly cooking them would kill any virus anyway.

Farms are prohibited from selling products including milk and eggs from sick animals, so its unlikely that contaminated food would wind up on grocery store shelves. The most likely impact of the bird flu outbreak in animals on the food supply is rising prices. Egg prices have shot up as chickens have been culled or died, limiting the supply of eggs. Milk prices could see increases but are stable so far.

On April 15, Colombia became the first country to restrict the importation of beef and beef products from U.S. states with infected herds, Reuters reported.

Two candidate vaccines drafts of what would become the shots seem to be good matches for the current strain of bird flu, the Washington Post reports. The federal government has a stockpile of enough doses to vaccinate a fifth of the American population, officials told Barron's. However, the vaccines are undergoing clinical testing, so it's unclear how effective they will be. Antiviral drugs can also be used to treat bird flu, although the CDC says that some variations of bird flu first found in Asia arent as responsive to these treatments.

Dr. Arnold Monto, a professor emeritus of epidemiology at the University of Michigan and member of the FDAs vaccine committee, tells Yahoo Life that the U.S.s bird flu vaccines require adjuvants, ingredients that improve humans immune responses. An official with the Department of Health and Human Services also told the Washington Post that components for the vaccines are being tested, and it would likely take weeks to months for them to be ready for widespread distribution. Monto adds that the vaccine would also likely be given to only those at high risk poultry and dairy farmworkers since theres no evidence that bird flu spreads among humans.

Avoid close or prolonged contact with wild birds, cattle or any other animal suspected of being infected. The CDC also recommends steering clear of surfaces that may be contaminated with raw milk, animal feces, litter or anything else that might have crossed paths with an infected animal.

Cooking poultry and eggs to an internal temperature of 165F will kill off any virus. It's also recommended for milk drinkers to consume only pasteurized milk to prevent contracting bird flu or other viruses or bacteria from raw foods, and to avoid raw or undercooked foods sourced from animals that may be infected with bird flu.

This article was originally published on April 4, 2024. It has since been updated.

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Bird flu: The latest on U.S. spread, the safety of milk and new federal funding to prevent outbreaks - Yahoo Life

U.S. health and agriculture officials pledged nearly $200 million in new spending and other efforts Friday to help track and contain an outbreak of bird flu in the nations dairy cows that has spread to more than 40 herds in nine states.

The new funds include $101 million to continue work to prevent, test, track and treat animals and humans potentially affected by the virus known as Type A H5N1, the U.S. Department of Health and Human Services said. And they include about $98 million to provide up to $28,000 each to help individual farms test cattle and bolster biosecurity efforts to halt the spread of the virus, according to the Agriculture Department.

In addition, dairy farmers will be compensated for the loss of milk production from infected cattle, whose supply drops dramatically when they become sick, officials said. And dairy farmers and farm workers would be paid to participate in a workplace study conducted by the USDA and the Centers for Disease Control and Prevention.

So far, farmers have been reluctant to allow health officials onto their farms to test cattle because of uncertainty about how it would affect their businesses, researchers have said. Also, farm workers, including many migrant workers, have been reluctant to be tested for fear of missing work or because they didnt want to be tracked by the government.

The National Milk Producers Federation, a trade group representing dairy farmers, said they welcomed the new resources. Care for farm workers and animals is critical for milk producers, as is protecting against potential human health risks and reassuring the public, the group said in a statement.

The incentives should help increase farmers willingness to test their herds, said Keith Poulsen, director of the Wisconsin Veterinary Diagnostic Laboratory, who has been monitoring the outbreak.

It provides the latitude and capacity to start going in the right direction, he said.

The new spending comes more than six weeks after the first-ever detection of an avian bird flu virus in dairy cattle and one confirmed infection in a Texas dairy worker exposed to infected cows who developed a mild eye infection and then recovered. About 33 people have been tested and another 260 are being monitored, according to the CDC.

As of Friday, 42 herds in nine states have confirmed infections in dairy cows. Agriculture Secretary Tom Vilsack said that the outbreak has not spread more widely.

Its still in the same nine states and thats the most positive thing about where we are, he told reporters.

Samples of grocery store milk tested by the U.S. Food and Drug Administration showed remnants of the virus in about 1 in 5 samples of retail milk nationwide, however, suggesting that the outbreak could be more widespread, scientists have said.

Under a federal order issued last month, farmers are required to test lactating dairy cattle for H5N1 before the animals are moved between states. The Agriculture Department said Friday that 112 out of 905 tests conducted between April 29 and May 5 by federal animal health laboratories appeared to be positive. Officials could not say how many cows tested positive because multiple samples may have been collected from a single cow. Labs are conducting about 80 more tests per day than before the order took effect, an Agriculture Department spokesman said.

About 50,000 dairy cattle typically cross state lines every week, Poulsen estimates.

The FDA found that pasteurization, or heat-treating, killed the virus in the grocery samples of milk, cottage cheese and sour cream. The agency reiterated warnings that people should not consume raw, or unpasteurized milk, because of possible risk from the virus. Officials on Friday also said they expect results soon from tests of pooled raw milk samples sent to commercial processors to determine potential levels of virus that pasteurization must eliminate. The USDA found no evidence of the virus in a small sample of retail ground beef.

The risk to the public from this outbreak remains low, Health and Human Services Secretary Xavier Becerra said.

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US pledges to help track and contain bird flu on dairy farms - Chicago Tribune

May 9, 2024 Bird fluH5N1 avian flu virushas been spreading among dairy cows across the U.S. So far, theres only one known case of the virus possibly passing from a cow to a human, but experts are concerned there may be more cases we dont know about, and about the potential for further spread. Bill Hanage, associate professor of epidemiology at Harvard T.H. Chan School of Public Health, doesnt think that a bird flu pandemic is imminent at least not yet.

Q: Some experts are saying that the spread of bird flu in cows may be much broader than it appears. Why would that be? Why wouldnt we have a handle on the spread?

A: Outbreaks at the interface of animal and human health are hard to study in the U.S. because theyre covered by different jurisdictions. The USDA [U.S. Department of Agriculture] oversees farm issues and its focus is on agriculture. While the USDA does have an emergency response team dedicated to influenza, farmers may have concerns about people coming onto their property to collect samples from livestock or workers, and some of those workers may not have documented immigration status. But those workers are at risk of infection, as shown by a case of human infection that occurred in early April. Samples from animals at the relevant farm were reportedly not available for testing.

If we cant collect samples directly from cattle, we have to look at something like milk, and we have indeed found that a lot of tested milk samples contain genetic traces of the bird flu. But that does not tell us how many cows might be infected. Its not at all clear because the milk we are testing is not from just one cow but many, and so we have no idea how many of them were contributing to the signal. All we can say is that it is certainly not a small number given how many samples are coming back positive, but beyond that we just dont know exactly how many infected cows there are, where they are, or how many may have been very mildly infected and not detected.

One of the problems is the way public health has been politicized following the COVID pandemic. But the virus doesnt care what side youre onit only cares if you have the appropriate receptors so that it can get into your cells, and from there into somebody else.

Q: What sort of information would help scientists figure out the extent of bird flu spread among cows?

A: Much more sampling, from cattle with and without symptoms, as well as from workers who have contact with them. Ideally this would include antibody tests to determine whether they have been infected and recovered in the past. Transparency is really important when it comes to public health.

While genomes from the outbreak have been made available by the USDAalthough they did not do so with alacritythey were initially criticized for lacking essential content such as when and where the samples were collected, which is really important to start making sense of the spread. It now looks like there was a single introduction from birds into dairy cattle in Texas, which was then disseminated to other states via movement of asymptomatic cattle. We can also see that the genetic variation is consistent with rapid exponential growth. The USDA has recently required dairy cattle to test negative for the virus before being transported across state lines, which is a welcome step. Although at present testing is only required for dairy cows that are lactating, so it is easy to see how the virus could slip through the net. In any case, this may be a case of shutting the barn door after the cow has bolted.

Q: As of now, theres just one known instance in which a cow appears to have infected a human with bird flua case of conjunctivitis in a dairy farm worker from Texas. How could the virus start spreading more in humans?

A: It could adapt to bind to the receptors that are found in our upper airways, which would help respiratory spread. Right now it sticks to receptors deeper in the lung, which is one reason why infections there, when they occur, are so nasty. Cows dont typically get respiratory infections with the sort of flu viruses that transmit among humans because they dont have the right receptors in the right place. Instead, milk production seems to be key for transmission in the current outbreak. But pigs can be infected by all sorts of different flu viruses that are also capable of respiratory spread among humans. Previously weve seen pandemics arise from whats called reassortment, in which a pig gets infected with two different viruses, and the genetic material gets mixed up in the pig, and what comes out is a new virus with new properties. Thats one way that the virus might make an evolutionary leap and start to transmit among humans, so we should keep a close eye on pigs to see whether the cattle outbreak is seeding infections into them.

Q: If the virus does start spreading in humans, could that cause another pandemic?

A: It certainly could but it would depend on the state of our immunity to whichever virus gets lucky and exactly how transmissible it is. As it happens, the infections that have been occurring in Texas seem to be a type that is a good match for some existing components of a vaccine that we would be able to start making.

On the other hand, vaccines dont appear from thin air; they take time to produce. One of the major ways that we make them involves hens eggs. Dont forget, were dealing with an avian flu that has affected chickensoutbreaks in poultry farms in two states have recently been detected. As a result of bird flu outbreaks, eggs have been in short supply at some points in the last few years, and that could make ramping up production of a vaccine a more difficult task. We wont be able to do it overnight. It would take months at the very least.

Another tool we have is the antiviral drug Tamiflu. But to be effective, it needs to be given quite early on in the infection. So we also need to have tests ready.

Q: So if the virus did start to spread quickly, how prepared are we?

A: What disturbs me most about this is that theres no serious discussion about what we would do if the you-know-what hits the fan. If we were to see any evidence of human-to-human transmission without links to livestock, that would be immensely concerning. If we see larger numbers of such infections in clusters, or even more than one cluster, it would be time to start making vaccinetime to pull out all the stops. The reason is that, in the early stages of infectious disease outbreaks, youre always playing catchup. Youre racing behind the virus, seeing where it has been, not where it is. You can bet that if we are seeing cases, there are others that were not seeing.

Q: Genetic material from H5N1 has been found in pasteurized milk, and the FDA has been testing ground beef. Should we be concerned about risk to humans?

A: Pasteurization inactivates the virus, so pasteurized milk is safe. And right now tests on ground beef have come back negative. We should remember that these tests are exquisitely sensitive, and do not reflect live virus. However, I would avoid unpasteurized or raw milk products. There have been several infections in cats that almost certainly were exposed by drinking milk on the farms in question.

Q: Whats the bottom line? How worried should we be about an outbreak?

A: If it was easy for this virus to spread among humans, it would have likely done it already. Having said that, this strain is far better than most bird flu at infecting all sorts of different mammalsthere have been outbreaks in seals, farmed mink, and now cattle. We have seen sporadic spillover infections in skunk and racoons among others, as well as the single human case identified so far. All of that indicates that this is a generalist virus [one that can infect and evolve in multiple species]and those are the ones you want to keep an eye on.

Even though I dont think theres reason to believe a pandemic is imminent right now, we will have another flu pandemic at some point, and we should be ready for it. Not having a plan is just beyond stupid. Dont panic, do prepare.

Karen Feldscher

Photo: iStock/Sabrina Gordon

Original post:

Bird flu, pandemic risk, transparency, planning | News | Harvard T.H. Chan School of Public Health - HSPH News

Highly Pathogenic Avian Influenza (HPAI) is a disease that is highly contagious and often deadly in poultry, caused by highly pathogenic avian influenza A (H5) and A (H7) viruses; it is also known as bird or avian flu. HPAI viruses can be transmitted by wild birds to domestic poultry and other bird and animal species. Although bird flu viruses do not normally infect humans, sporadic human infections have occurred. It is important to note that highly pathogenic refers to severe impact in birds, not necessarily in humans.

What's New|Previous Updates

Background (including: Review of Available Data, OngoingResearch, DataConsiderations,Precautions for Raw Milk, andConclusions)

Additional Resources

May 10, 2024

The FDA, alongside our federal and state partners, is continuing to take a stepwise approach to our scientific analysis of commercial milk safety during the first-of-its-kind detection of HPAI H5N1 in dairy cattle. While our initial assessment of the milk safety system continues to be affirmed by sampling and testing of retail dairy products, there remain a number of collective activities being undertaken to ensure the continued effectiveness of the federal-state milk safety system. The FDA will continue to follow a sound scientific process to inform the agencys public health decisions related to food safety.

Last week we announced preliminary results of a study of 297 retail dairy samples, which were all found to be negative for viable virus. The FDA is today announcing that all final egg inoculation tests associated with this retail sampling study have been completed and were also found to be negative for viable HPAI H5N1 virus. These confirmatory test results mark the completion of our laboratory research efforts related to these 297 retail dairy samples. Additional sampling and other surveillance activities will continue.

While our retail sampling test results to date are clear about the safety of the commercial milk supply and representative of real-world scenarios, additional scientific work is being undertaken to validate the criteria for pasteurization relative to the HPAI H5N1 virus and will include tests using pasteurization equipment typically used by milk processors. Today, wed like to share more about our additional research efforts.

The established pasteurization process set forth in federal regulation (21 CFR 1240.61) and the Pasteurized Milk Ordinance (PMO) provides specific temperature and time requirements for effective elimination of known pathogens in the milk supply. To further validate pasteurization effectiveness against this recently detected virus, the FDA previously noted it was testing samples of pooled raw milk routed for commercial processing to characterize potential virus levels that the pasteurization process must eliminate. Our pasteurization study is designed to better replicate real-world conditions to deliver the pasteurization treatment parameters set forth in the CFR and PMO, and to assess their effectiveness in inactivating HPAI H5N1 in bovine milk and other dairy products.

The results from this study will help further the FDAs understanding of pasteurization efficacy against anticipated concentrations of virus under real-world processing conditions. The pasteurization study is ongoing and we anticipate making preliminary results available in the near future.

Today, the agency is also announcing an additional $8 million is being made available to support its ongoing response activities to ensure the safety of the commercial milk supply. This funding will support the agencys ability to validate pasteurization criteria, conduct surveillance at different points in the milk production system, bolster laboratory capacity and provide needed resources to train staff on biosecurity procedures.

Additionally, these funds will help support HPAI H5N1 activities in partnership with state co-regulatory partners, who administer state programs as part of the federal/state milk safety system. It may also allow the FDA to partner with universities on critical research questions.

To date, the totality of evidence including studies on the effectiveness of pasteurization against multiple pathogens, recent studies on the effectiveness of pasteurization of HPAI H5N1 in eggs at lower temperatures than generally used in dairy products, negative retail sample results to date, and real-world evidence from the last 100 years of the PMO continues to indicate that the commercial milk supply is safe.

At the same time, the FDA also continues to advise against the consumption of raw milk (milk that has not been pasteurized). The FDA and CDC have long standing information regarding the increased risk of foodborne illness associated with numerous pathogens that may be present in raw milk. This increased risk exists for both humans and other animals that might drink raw milk. Additional guidance on raw milk and milk handling can be found on our website.

We are committed to continuing to initiate, support, and collaborate on research and surveillance of milk production, processing, and pasteurization to further our public health goals.

This additional preliminary testing did not detect any live, infectious virus.

In addition to preliminary results released late last week on an initial set of 96 retail milk samples, these results reaffirm our assessment that the commercial milk supply is safe.

To ensure the safety of milk-derived products for our youngest populations, the FDA also tested samples of retail powdered infant formula and powdered milk products marketed as toddler formula. All qPCR results of formula testing were negative, indicating no detection of HPAI H5N1 viral fragments or virus in powdered formula products so no further testing was required for these samples. The FDA is continuing to identify additional products that may be tested.

The FDA is also continuing to test samples of pooled raw milk that has been routed to pasteurization and processing for commercial use. This will be used as a basis to characterize potential virus levels that pasteurization may encounter and will be used to inform studies to further validate pasteurization.

As this situation evolves, the FDA will continue to consider all ongoing scientific research related to the effectiveness of pasteurization for HPAI in bovine milk. We are also committed to continued surveillance of milk production, processing and pasteurization to help ensure the safety of the milk supply. Our state partners are integral to this process, and we are working with them on a continual basis. We will also continue working with our state co-regulators on managing this emerging disease.

The FDA continues to advise strongly against the consumption of raw milk and recommends that industry does not manufacture or sell raw milk or raw milk products.

This additional testing did not detect any live, infectious virus. These results reaffirm our assessment that the commercial milk supply is safe.

In addition, several samples of retail powdered infant formula were tested, as well as powdered milk products marketed as toddler formula. All qPCR results of formula testing were negative, indicating no detection of viral fragments or virus in powdered formula products.

The FDA is further assessing retail samples from its study of 297 samples of retail dairy products from 38 states. All samples with a PCR positive result are going through egg inoculation tests, a gold-standard for determining if infectious virus is present. These important efforts are ongoing, and we are committed to sharing additional testing results as soon as possible. Subsequent results will help us to further review our assessment that pasteurization is effective against this virus and the commercial milk supply is safe.

Epidemiological signals from our CDC partners continue to show no uptick of human cases of flu and no cases of HPAI H5N1, specifically, beyond the one known case related to direct contact with infected cattle.

Today, the FDA received some initial results from its nationally representative commercial milk sampling study. The agency continues to analyze this information; however, the initial results show about 1 in 5 of the retail samples tested are quantitative polymerase chain reaction (qPCR)-positive for HPAI viral fragments, with a greater proportion of positive results coming from milk in areas with infected herds. As previously noted and outlined in our summary below, qPCR-positive results do not necessarily represent actual virus that may be a risk to consumers. Additional testing is required to determine whether intact pathogen is still present and if it remains infectious, which would help inform a determination of whether there is any risk of illness associated with consuming the product. The FDA is further assessing any positive findings through egg inoculation tests, a gold-standard for determining if infectious virus is present. Early work by NIH-funded investigators indicates an absence of infectious virus in their studies of retail milk. To date, the retail milk studies have shown no results that would change our assessment that the commercial milk supply is safe. Epidemiological signals from our CDC partners continue to show no uptick of human cases of flu and no cases of HPAI H5N1, specifically, beyond the one known case related to direct contact with infected cattle. These important efforts are ongoing, and we are committed to sharing results from both the qPCR and egg inoculation tests as soon as possible.

The U.S. Department of Agriculture (USDA), the U.S. Food and Drug Administration (FDA), and the Centers for Disease Control and Prevention (CDC), along with state partners, continue to investigate an outbreak of highly pathogenic avian influenza (HPAI) virus impacting dairy cows in multiple states. Infection with the virus is causing decreased lactation, low appetite, and other symptoms in affected cattle.

The FDA and USDA have indicated that based on the information currently available, our commercial milk supply is safe because of these two reasons:

1) the pasteurization process and

2) the diversion or destruction of milk from sick cows.

The pasteurization process has served public health well for more than 100 years. Pasteurization is a process that kills harmful bacteria and viruses by heating milk to a specific temperature for a set period of time to make milk safer. Even if virus is detected in raw milk, pasteurization is generally expected to eliminate pathogens to a level that does not pose a risk to consumer health. However, pasteurization is different than complete sterilization; sterilization extends shelf life but is not required to ensure milk safety. While milk is pasteurized, not sterilized, this process has helped ensure the health of the American public for more than 100 years by inactivating infectious agents.

Nearly all (99%) of the commercial milk supply that is produced on dairy farms in the U.S. comes from farms that participate in the Grade A milk program and follow the Pasteurized Milk Ordinance (PMO), which includes controls that help ensure the safety of dairy products. Pasteurization and diversion or destruction of milk from sick cows are two important measures that are part of the federal-state milk safety system.

There are a number of collective activities being undertaken to ensure the continued effectiveness of the federal-state milk safety system. In addition to these specific research activities, the FDA is collaborating closely with CDC's food safety group, as well as its surveillance team thats monitoring emergency department data and flu testing data for any unusual trends in flu-like illness, flu, or conjunctivitis. To date, surveillance systems do not show any unusual trends or activity.

As noted by USDA and some press reports from the World Health Organization (WHO) and other sources, the presence of the 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. Therefore, some of the samples collected have indicated the presence of HPAI using quantitative polymerase chain reaction (qPCR) testing.

During the course of the outbreak, the FDA has been evaluating milk from affected animals, in the processing system, and on the shelves. We are completing a large representative national sample, to better understand the extent of these findings. Because qPCR findings do not represent actual virus that may be a risk to consumers, the FDA is further assessing any positive findings through egg inoculation tests, a gold-standard for determining viable virus. To date, we have seen nothing that would change our assessment that the commercial milk supply is safe. Results from multiple studies will be made available in the next few days to weeks.

Sound science is critical to informing public health decisions like those made by the FDA related to food safety and we take this current situation and the safety of the milk supply very seriously. We recognize the importance of releasing further, actionable information.

Review of Available Data

Given that the detection of H5N1 in dairy cows is a novel and evolving situation, no studies on the effects of pasteurization on HPAI viruses (such as H5N1) in bovine milk have previously been completed although considerable scientific literature is available that has informed our current understanding.

The established pasteurization process set forth in the PMO provides specific times and temperature requirements [i] for effective pasteurization of known pathogens in the milk supply. Data from previous studies [ii, iii], that serve as the underpinnings of the FDAs current milk supply safety assessment show that pasteurization is very likely to effectively inactivate heat-sensitive viruses, like H5N1, in milk from cows and other species. Additionally, data [iv, v, vi] shows thermal inactivation of HPAI (H5N1) has been successful during the pasteurization process for eggs, which occurs at lower temperatures than what is used for milk.

Ongoing Research

U.S. government partners have been working with deliberate speed on a wide range of studies looking at milk along all stages of production -- on the farm, during processing and on shelves -- using well- established methodologies used previously to confirm pasteurization effectiveness for known pathogens.

This work is a top priority, and we are proceeding in an efficient, methodical, and scientific fashion to ensure the continued effectiveness and safety of the federal-state milk safety system.

Laboratory benchtop tests are the first part of this ongoing work. This includes testing laboratory generated samples inoculated with high levels of a recently isolated and closely related avian flu virus and samples of raw, unpasteurized milk directly from cows in affected herds with and without symptoms to understand how, and at what levels, heat treatment (pasteurization) inactivates the virus.

While this information is important, this testing alone cannot provide a complete picture as these samples are not representative of what we would expect to see in the real-world from milk routed to pasteurization and processing for commercial use.

In addition to lab testing, a critical step in the scientific confirmation process includes testing of milk that is representative of real-world scenarios in which milk is typically pooled in large amounts from numerous healthy cows from numerous farms before pasteurizing and processing.

Work is underway to test samples of milk in systems that represent current industry practices using the range of temperature and time combinations that are used in pasteurization processes.

Additional analysis is underway of milk on store shelves across the country in addition to work to evaluate any potential differentiation for various types of dairy products (e.g., whole milk, cream).

We are aware that universities or other entities are conducting work in this area, particularly universities and consortia supported by the National Institutes of Health. We look forward to reviewing all results generated from various scientific studies, testing methods and the product(s) used as we continue assessing all the data and information available. We are committed to collaborating with the broad community to come to sound scientific conclusions regarding this situation -- which its important to understand takes time.

Data Considerations

Multiple tests are used to assess the safety of food items. Understanding how and why different methodologies are used and work, as well as how results fit into the larger picture, is critical to interpret any findings.

Precautions for Raw Milk

The FDA has a long-standing recommendation to consumers not to consume raw milk (milk that has not been pasteurized). Because of the limited information available about the possible transmission of H5N1 virus via raw milk, the FDA continues to recommend that industry does not manufacture or sell raw milk or raw milk products, including raw milk cheese, made with milk from cows showing symptoms of illness, including those infected with avian influenza viruses or exposed to those infected with avian influenza viruses.

Importantly, the FDA has also recommended producers take precautions when discarding milk from affected cows so that the discarded milk does not become a source of further spread. Producers should consult with their state regulatory authorities for specific recommendations or requirements; however, such precautions should include heat treatment, pasteurization or its equivalent, of discarded milk prior to dumping in lagoons or application of waste solids and ensuring biosecurity around lagoons (e.g., ensuring that animals and birds do not have access to lagoons). Any raw milk or raw milk products from exposed cattle that are fed to calves (or to other animals, such as farm cats) should be heat treated or pasteurized.

Conclusion

The PMO and pasteurization continue to provide important measures to assure milk safety. Given this is the first time we have seen this virus affect cows, these are the first studies that have been initiated to look at the effectiveness of pasteurization on HPAI viruses such as H5N1 in bovine milk.

As previously noted, the FDA is collaborating closely with CDC's food safety group, as well as its surveillance team thats monitoring emergency department data and flu testing data for any unusual trends in flu-like illness, flu, or conjunctivitis. To date, surveillance systems do not show any unusual trends or activity. Only one associated human case from a person exposed to infected cows has been linked with this outbreak in dairy cows to date and CDC says risk to the general public remains low.

The FDA and USDA are working closely to collect and evaluate additional data and information specific to H5N1 in dairy cattle and to support state counterparts as this emerging disease in dairy cattle is managed. These important efforts are ongoing, and we are committed to sharing results as soon as possible. In the meantime, the FDA and USDA continue to indicate that based on the information we currently have, our commercial milk supply is safe.

i. 21 CFR part 131 -- milk and cream. (n.d.). https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-131

ii. Pitino, M. A., OConnor, D. L., McGeer, A. J., & Unger, S. (2021). The impact of thermal pasteurization on viral load and detectable live viruses in human milk and other matrices: a rapid review. Applied Physiology Nutrition and Metabolism, 46(1), 1026. https://doi.org/10.1139/apnm-2020-0388

iii. Jay, J. M., Loessner, M. J., Golden, D. A., & Keller, H. B. (2005). Food Protection with High Temperatures. In Modern Food Microbiology (pp. 415441). https://link.springer.com/chapter/10.1007/0-387-23413-6_17

iv. Chmielewski, R. A., Beck, J. R., & Swayne, D. E. (2011). Thermal inactivation of avian influenza virus and Newcastle disease virus in a fat-free egg product. Journal of Food Protection, 74(7), 11611169. https://doi.org/10.4315/0362-028x.jfp-10-415 https://doi.org/10.4315/0362-028x.jfp-10-415

v. Chmielewski, R. A., Beck, J. R., & Swayne, D. E. (2013). Evaluation of the U.S. Department of Agricultures egg pasteurization processes on the inactivation of high-pathogenicity avian influenza virus and velogenic Newcastle disease virus in processed egg products. Journal of Food Protection, 76(4), 640645. https://doi.org/10.4315/0362-028x.jfp-12-369

vi. Chmielewski, R. A., Beck, J. R., Juneja, V. K., & Swayne, D. E. (2013). Inactivation of low pathogenicity notifiable avian influenza virus and lentogenic Newcastle disease virus following pasteurization in liquid egg products. Lebensmittel-Wissenschaft Und Technologie [Food Science and Technology], 52(1), 2730. https://doi.org/10.1016/j.lwt.2013.01.002

Here is the original post:

Updates on Highly Pathogenic Avian Influenza (HPAI) - FDA.gov

Just when you stopped regularly hearing about COVID-19 in the news, another infectious disease began to dominate headlines this spring: bird flu.

The good news isfor now, at leastpublic health experts dont see this latest bout of avian influenza evolving into the likes of the coronavirus pandemic. But given the disease has spread to poultry in 48 states, dairy cows in nine, and two people in Texas and Colorado, you may be worried about its potential impact on your health.

Fortune spoke with a trio of epidemiologists, who below answer critical public health questions about bird flu.

The type of bird flu thats currently circulating is a highly pathogenic avian influenza (HPAI)a disease that can seriously sicken wild and domestic birds, posing a major threat to the poultry industry and thereby the global economy, according to the U.S. Department of Agriculture (USDA). The other kind, low pathogenicity avian influenza, causes mild infection in wild fowl but can turn into HPAI in poultry.

Influenza viruses are divided into four types, A, B, C, and D, explains Edwin Michael, PhD, an epidemiologist at the University of South Florida College of Public Health. What we think of as the seasonal flu in humans is caused by types A and B. Bird flu falls under the umbrella of influenza A viruses. The strain currently spreading in the U.S. is H5N1, an HPAI named for proteins on the viruss surface.

It can spread very quickly through the bird populationwild birds. That can spread it all across the world, Michael tells Fortune. From the bird, the virus is shed in mucus, saliva, feces, and then that can go and get into domestic poultry.

When HPAI strains reach domestic poultry, they can kill entire flocks within days, the USDA says. Birds with HPAI infection may show a slew of symptoms including diarrhea, lack of energy and appetite, and a drop in egg production. Because HPAI cant be treated, poultry depopulation is the sole solution.

Such culling can be effective in curtailing the spread in birds crucial to U.S. agriculture and food production, says Dr. William Schaffner, a professor in the Division of Infectious Diseases at Vanderbilt University Medical Center.

This particular bird flu virus, in its variants, has actually been around for a long timeover a decade, Schaffner tells Fortune. Its been gradually spreading but recently, somehow, for reasons that at least I dont understand, its spread around the world has become much more prominent and much more widespread.

H5N1 is a shapeshifter, so to speak, due to its segmented DNA, Michael explains.

For example, if a human gets infected with a bird flu and also carries a human influenza A virus, these two viruses can exchange genetic material. This is known as genetic shift, Michael says. That can form very new viruses [and] cause epidemics.

Flu pandemics are rare, though, occurring roughly three times a century, Michael says. Perhaps the most notable is the so-called Spanish flu of 19181919, when the Centers for Disease Control and Prevention (CDC) estimates an avian-like H1N1 virus killed 50 million, and possibly as many as 100 million, people worldwide.

You probably remember the swine flu pandemic of 2009, caused by a previously unknown H1N1 virus that contained swine, human, and avian genes. How did that happen? Because bird flu viruses dont always effectively spread among humans, they sometimes need help from other species to thrive, Schaffner explains.

The pigs respiratory tract is set up in such a way that it can accept bird flu infections andandinfections with a human virus, Schaffner says. You could think of the pig as a test tube into which goes a bird flu and a human flu, and if that happens simultaneously in the same pig, then those two viruses get together and can have the capacity to exchange genetic elements.

While the latest H5N1 strain isnt known to spread among humans, it has already spilled over to more than a dozen species of wild mammals, from black bears to a bottlenose dolphin. As recently as May 3, red foxes in New York and Michigan tested positive, according to the USDAs Animal and Plant Health Inspection Service (APHIS).

This bird flu virus is not relying on pigs but is mutating on its own to become a more effective infection in a variety of different mammalian species, Schaffner says. The one that has been in the news is dairy cattle, which surprised every virologist.

Government agencies have been monitoring the latest bird flu outbreaks since Jan. 12, 2022, when a Northern Shoveler duck in Hyde County, North Carolina, tested positive for a Eurasian strain of H5N1.

Among wild birds, the disease had spread throughout more than 1,100 counties as of May 8, 2024, infecting nearly 9,400 fowl.

The situation is worse in U.S. poultry. As of May 7, nearly 91 million birds, including commercial poultry and backyard flocks, had been infected. This encompasses more than 1,100 outbreaks in 522 counties across 48 states.

APHIS recorded the first poultry infection in a commercial turkey flock in Dubois County, Indiana, on Feb. 8, 2022.

Though H5N1 has been circulating nationwide in wild birds, domestic poultry, and mammals since 2022, you may have only been hearing about it recently because of its jump to dairy cattle. The first positive case was documented in Texas on March 25, 2024.

As of May 7, nearly 40 dairy cattle herds had been infected across nine states.

The logistics of modern industrial farming may be fueling the H5N1 spread to cattle, Michael says.

Look at the density of animals in those farmsthose are not natural settings, Michael tells Fortune. So as soon as you get [an infection], these things will spread very quickly among farm animals.

Michael adds, We have to shed a light on how farming is done. Thats the trade-off, you want cheap meat and all the rest of it, but then you farm animals in this way and youre opening the door up for other things.

The Food and Drug Administration (FDA) acknowledges the presence of bird flu in dairy cows is a novel and evolving situation. That said, no previous studies have been done on the effects of pasteurizationa sterilization measure that kills harmful bacteriaon HPAI in bovine milk. However, the FDA says existing research has informed its understanding and conclusion that milk consumption is safe.

The FDA and USDA are conducting a national commercial milk sampling study, which includes milk-derived baby formula. As of May 1, no HPAI had been detected in any formula products. While bird flu had shown up in milk, sour cream, and cottage cheese samples, pasteurization inactivated the virus.

There is no need to be concerned about milk, eggs, [and] chicken as sources of infection, Schaffner tells Fortune. Im out there drinking milk, and we had chicken last night for dinner.

Both Schaffner and the FDA urge the public to steer clear of raw, unpasteurized milk. The CDC recommends cooking eggs and poultry to an internal temperature of 165 degrees to kill bacteria and viruses, H5N1 included.

Simply put, dont panic, says Michael Osterholm, PhD, director of the Center for Infectious Disease Research and Policy at the University of Minnesota.

Theres no evidence yet at this point that this is an imminent risk to humans, Osterholm tells Fortune. Weve not seen it cross over to humans in a way that would support that its going to be the next pandemic virus.

On the other hand, a reassortant event, or continued mutations, could occur tomorrow.

Two humans have so far caught H5N1, according to the CDC. A person exposed to dairy cattle in Texas tested positive April 1, 2024, and a person in Colorado involved in culling poultry tested positive April 28, 2022. No human-to-human transmission has been confirmed, and the more recent patients only symptom was conjunctivitis, or pink eye.

We do have two, three receptor sites in our eyes, and so having a case of conjunctivitis would not be considered unusual, Osterholm says. There was no evidence of any kind of respiratory infection, which is the key piece for serious illness and then being able to transmit the virus.

The Texas case marks the first time a human has been infected with H5N1 through contact with a mammal, according to the World Health Organization (WHO). Even so, WHO considers the public health risk to the general population low. For farmworkers and other industry staff likely to be exposed to the virus, the risk is low to moderate.

Going forward, assuring the health and safety of agriculture workers is paramount to keeping H5N1 from spreading to the wider population, Michael says.

I dont think this one is going to be a major outbreak (in humans), Michael says. [But] the risk is always, always there because of the way we manage nature.

For more on the latest bird flu outbreak:

Originally posted here:

Bird flu FAQ: H5N1 dairy cow outbreak in Texas, New Mexico, Michigan - Fortune

It emerged as a powerful tool for public health officers during the COVID-19 pandemic, when it was used to gauge the prevalence of coronavirus in communities across the nation.

But wastewater surveillance the testing of sewage for signs of pathogens such as SARS-CoV-2, poliovirus and mpox virus has yet to be employed in the tracking of H5N1 bird flu virus.

Now, as officials attempt to determine the extent of bird flu outbreaks among dairy herds, some experts are urging that wastewater surveillance begin immediately. Others are faulting the U.S. Centers for Disease Control and Prevention for reportedly discouraging its use.

It has been consistently demonstrated that wastewater surveillance only enhances traditional surveillance, and often outperforms it when it comes to early/timely outbreak or surge detection, said Denis Nash, distinguished professor of epidemiology and executive director of City University of New Yorks Institute for Implementation Science in Population Health.

In this case, since traditional surveillance is not really systematically occurring, and wastewater surveillance is relatively low-cost and easy to implement, it makes a lot of sense to me to go ahead and deploy it strategically, said Nash, whose team developed New York Citys community-based wastewater surveillance for SARS-CoV-2.

That has not been the view of the CDC, however.

Recently, Marc Johnson, a professor of molecular microbiology and immunology at the University of Missouri, said he was told by the agency not to use a virus assay hed created for the purpose of tracking H5N1 outbreaks. The reason? Johnson said officials told him it would just add to the confusion.

Johnson said that if the assay had been in widespread use earlier this year, the spread of bird flu through the nations dairy herds could conceivably have been stopped, or at least slowed down.

I always think the more information we have, the better, he said.

However, he said he did understand the governments rationale.

Public health does not like ambiguous information, he said. You get a positive, you dont know if thats from a cow or a bird. Or maybe from milk poured down the drain.

The CDC did not respond to questions from The Times.

Concern over the virus escalated in March, when federal officials announced the discovery of avian flu in a Texas dairy herd. Over the next few weeks, reports of the virus in other states began to pop up. It also showed up in barn cats that drank raw milk, and in one dairy worker.

H5N1 bird flu has now been detected in 36 herds across nine states, and health and U.S. Department of Agriculture officials are scrambling to determine its reach. They believe the virus was introduced by a wild bird either via contact or feed at a Texas farm in December, giving the virus months to travel to other herds and animals.

The virus was also found in one of five grocery-shelf milk samples tested by federal researchers. Those samples showed the virus had been inactivated by pasteurization, reducing the health threat to people.

In California, where the virus has yet to be detected in dairy cows, wildlife officials are keeping a wary eye on migrating wild bird populations as well as domestic poultry and farm animals.

Eric Topol, a professor of molecular medicine at Scripps Research Institute in La Jolla, said the CDC is off base to say wastewater surveillance would cause confusion.

If anything, we need to track the spread of the virus and its evolution, which isnt getting done well by USDA and CDC, he said.

Michael Payne, a dairy educator and researcher at the University of Californias School of Veterinary Medicine, agreed with that sentiment. Although he was not familiar with the assay Johnson devised, he said an accurate test would be valuable.

Such a wastewater assay could be a useful tool, even given the uncertainty of exactly where the virus was coming from, he said. There is a growing body of literature that is using PCR testing in wastewater to measure pathogens of public health interest.

Nash, of CUNY, said hed advocate for a strategic deployment of community-based and facility-based wastewater surveillance.

He said testing wastewater at hospitals and health clinics would provide clear signals if an outbreak were to occur. Starting testing now, when a baseline for other confusing elements such as contaminated milk and bird droppings could be established, would help quell that noise.

He said that in the current situation, we need reliable early warning because if community spread did happen, every additional day of notice would matter a great deal in terms of potential lives saved.

Continued here:

Experts blast CDC over failure to test sewage for signs of H5N1 bird flu virus - Los Angeles Times

The federal government Friday unveiled a major package of financial incentives to dairy farm owners up to $28,000 per farm over the next four months to encourage broader testing of cattle and expanded security measures to control a growing outbreak of the bird flu virus in cows.

The $98 million in incentives from the Department of Agriculture, available only to farms with infected herds, is being offered as federal officials grapple with critical questions over how the virus has been spreading among dairy herds since the H5N1 bird flu was first detected in dairy cows in late March. Federal officials are trying to determine the risks for human exposure and how long livestock shed the virus in their milk once they have recovered from an infection.

More here:

Federal dollars to increase bird flu testing for dairy cows, farm workers - The Washington Post