MISSOULA H5N1 also known as bird flu has been slowly infecting new animals across the country, including dairy cows.
A recent development has been that some people who work on dairy farms have also been infected.
While no dairy herds in Montana have been infected by the bird flu that doesnt mean the virus hasnt been showing up in other animal populations in the state.
That is something that is raising alarms within the scientific community.
I think we've had close to 20 flocks here in Montana since 2022 that's impacted about 150,000 birds in the state, said Montana State Veterinarian Tahnee Szymanski.
In addition to the threat to poultry populations, bird flu has been found in wild birds, lynx, barn cats and even grizzly bears. However, Szymanski noted that transmission from wild animals is currently not a large concern. It's really interesting because they're using the genetic sequencing of the virus to show that it's not wild birds that are continuing to spread this particular variant that's in dairy cattle," Szymanski told MTN. "It's actually we're moving cattle around or we're moving the virus around on people, equipment, or whatever.
So what is being done to counteract this virus? MTN visited Rocky Mountain Laboratories in Hamilton where researchers have been studying H5N.
Zach Volheim/MTN News
Influenza. As I've mentioned, it may have mentioned is really kind of a shapeshifter of the virus. It's got a lot of tricks that it can pull," explained Rocky Mountain Laboratories Associate Director for Scientific Management Marshall Bloom.
The evidence so far is that the virus does not appear to be highly transmissible in humans, and scientists are trying to study why that is. Bloom explained there are five key points that they are looking into.
Those are why and how this virus infects certain animals, how can it be detected, how long it lasts on transmissible surfaces, how can they improve vaccines and what kind of countermeasures such as anti-viral drugs can be used to slow the virus.
While researchers are concerned about the virus being detected in humans, the concerns for a larger outbreak are still rather minimal at this point.
The risk to people right now is low. Our food supply is safe. Our commercial milk supply is safe," Szymanski told MTN. But we just want to be we want to be careful with that added Szymanski.
Currently, the overall threat of bird flu spreading between animals and people in Montana is rather low, but precautions are still being taken to make sure that remains the case.
More local news from KPAX
As the H5N1 bird flu outbreak in dairy cows enters its fourth month, the Centers for Disease Control and Prevention is taking steps to ramp up the nations capacity to test for the virus in people.
In a call with reporters Tuesday, Nirav Shah, the CDCs principal deputy director, emphasized that the risk to the general public remains low at this time. But given that the virus is showing no signs of slowing its push deeper into the U.S. cattle population threatening to create lasting risks to dairy workers and giving it more chances to evolve in ways that make it better at spreading to and among humans the agency is looking to increase the number and types of tests that can effectively detect H5N1 infections in people.
We need to stay prepared for the possibility of an expansion of the H5N1 outbreak in humans, Shah said.
Currently, the CDCs bird flu test is the only one the Food and Drug Administration has authorized for use. Shah said the agency has distributed 750,000 of these tests to local public public health labs, and is expecting 1.2 million more to come online in the next two to three months.
But should the virus begin to spread easily among humans, testing needs may quickly outpace existing public health laboratory capacity. Which is why the CDC is also working with commercial labs to build additional tests. So far, the agency has given eight companies licenses for its tests, Shah said. Three additional licenses are pending and another four companies are in the process of applying for licenses.
The effort appears to be aimed at avoiding mistakes the federal government made in the early months of the Covid-19 pandemic, when testing failures including a slow recruitment of commercial labs to the response allowed the coronavirus to spread undetected.
The CDC and local health departments have tried to boost bird flu testing among farmworkers including with financial incentives but uptake has been slow. Since the outbreak was recognized in March, the U.S. has tested only 53 people for novel influenza strains, which would include H5N1, according to the CDCs latest figures. Three people one farmworker in Texas and two in Michigan tested positive for the virus. Two experienced only minor symptoms, namely conjunctivitis, or pink eye. The third had more traditional flu-like respiratory symptoms, and all three recovered.
Many dairy workers are immigrants, who live in rural areas with little access to transportation and no sick leave, making it difficult to travel to health care providers for testing and treatment. While acknowledging these challenges, public health experts have criticized the lack of testing, which is making it difficult to know how many farmworkers have been infected. Insufficient surveillance could also mean public health agencies might miss signs of human-to-human spread of the H5N1 virus.
The labs granted CDC licenses will still have to have their versions of the CDC test cleared for use by the FDA before they can be rolled out. Part of that approval process is proving the tests work. And to conduct such validation studies, labs and diagnostics manufacturers need control materials samples that carry enough of the virus that they will light up a test as positive. That gets more complicated with a flu virus like H5N1, which is highly pathogenic, and therefore requires additional biosafety controls to work with in a lab.
To streamline the test validation process, the CDC is working to develop a non-virulent form of the control material, which it plans to provide to diagnostics manufacturers and commercial testing labs, although Shah did not provide a timeline for when they would become available.
The agency is also entreating the diagnostics industry to develop additional kinds of H5N1 tests, to broaden the nations portfolio of viral detection capabilities. On June 10, CDC put out a call for innovative testing solutions that can be easily ramped up to handle at least a million samples by the end of this year. The agency is now reviewing those applications, Shah said, with a goal of awarding funding to the winning companies by the end of August.
On Tuesday, the federal government also announced plans to support the development of messenger RNA-based pandemic influenza vaccines, including those that target H5 and H7 avian influenza viruses. BARDA, the Biomedical Advanced Research Development Authority, awarded Moderna $176 million to accelerate clinical testing of its pandemic vaccines, which are expected to enter a Phase 3 trial sometime next year. The U.S. government already has vaccine contracts and stockpiles of H5 vaccines made using other platforms by other manufacturers, including CSL Seqirus and Sanofi.
Dawn OConnell, assistant secretary for preparedness and response at the Department for Health and Human Services, said at the press briefing that nearly 5 million doses of H5 vaccine stored in bulk in the National Pre-Pandemic Influenza Vaccine Stockpile are now in the process of being put into vials, in case its needed. Our expectation is that those first doses will begin coming off the line in the middle of this month, OConnell said. We remain extraordinarily watchful regarding the situation that were all tracking regarding dairy cows and working very closely with our other public health partners trying to understand if and when we should move these vaccines from the lines and out into deployment.
As of Tuesday, the Department of Agriculture has reported infections in 137 dairy herds in 12 states. That tally doesnt include four additional infected herds reported by state authorities this week, including one each in Iowa and Minnesota and two in Colorado. With 27 outbreaks in Colorado most of which have occurred in the last month that state has now seen nearly one-quarter of its dairy herds infected with the virus.
FILE PHOTO: A dairy cow calls out in Chino, California, April 25, 2012. Photo by Alex Gallardo/Reuters
Afourth farm workerhas been infected with bird flu in the growing outbreak linked to dairy cows, health officials reported Wednesday.
The worker had direct contact with infected dairy cows on a northeast Colorado farm, state and federal health officials said. The man developedpink eye, or conjunctivitis, received antiviral treatment and has recovered.
READ MORE: How bird flu puts workers on farms and in food processing plants at higher risk
Three previous casesof human infection linked to cows have been reported in dairy workers in Texas and Michigan since March. Two of those workers also developed pink eye, while one had mild respiratory symptoms, In 2022, the first U.S. case of bird flu was detected in a Colorado farm worker exposed to infected poultry.
The Centers for Disease Control and Prevention said the new infection "does not change" the agency's assessment that the risk to the general public remains low. Surveillance systems tracking flu in the U.S. have shown no unusual activity, officials said. However, people with prolonged contact with to infected birds or other animals, including livestock, or to their environments, are at higher risk of infection.
The Colorado man was being monitored when he developed symptoms because of his work with dairy cows, according to the CDC. Tests at the state level were inconclusive, but samples sent to CDC tested positive. Full results of genetic analysis of the sample are pending.
As of Wednesday, more than 135 dairy herds in a dozen states had reported infections with the H5N1 virus thatoriginated in poultry,according to the Agriculture Department.
Left: FILE PHOTO: A dairy cow calls out in Chino, California, April 25, 2012. Photo by Alex Gallardo/Reuters
A fourth person has tested positive for bird flu in the outbreak linked to dairy cows, this time in Colorado.
The Centers for Disease Control and Prevention said Wednesday that the patient, a dairy worker at a farm where cows had also tested positive for the virus, had eye symptoms and has recovered after getting the antiviral drug Tamiflu.
The case mirrors the course of illness seen in two earlier cases in this outbreak, in Texas and Michigan dairy workers. The only symptoms either developed was pink eye. A third patient, also in Michigan, did develop upper respiratory symptoms, including sore throat, cough and congestion.
All of the patients have recovered, and none were connected to one another.
Based on the information available at this time, this infection does not change CDCs current H5N1 bird flu human health risk assessment for the U.S. general public, which the agency considers to be low, the agency said in a news release Wednesday.
There is no evidence, the CDC said, of increased flu-like illnesses that would indicate that the virus a strain called H5N1 is spreading widely in people.
Since the outbreak was first detected in March, more than 780 people exposed to sick cows have been monitored, and 53 have been tested for the virus, the CDC said Tuesday in a briefing with reporters.
Federal health officials said that 4.8 million doses of a vaccine for this particular flu strain could be available in the coming weeks. Drugmaker Moderna is also in the early stages of an mRNA vaccine for bird flu.
As of Wednesday, 139 herds in 12 states had been affected, according to the Department of Agriculture.
TheCDC recommendsthat anyone in contact with dairy cattle wear protective equipment, including safety glasses, waterproof aprons and boots that can be sanitized. Health officials also strongly warn against drinking unpasteurized raw milk. Pasteurization has been shown to neutralize the virus in milk samples.
Erika Edwards is a health and medical news writer and reporter for NBC News and "TODAY."
Researchers with the US Department of Agriculture (USDA) and US Food and Drug Administration (FDA), in a new preprint study, show that the H5N1 avian flu virus is inactivated through traditional pasteurization used in commercial milk processing.
In describing the findings, the FDA said the study compliments an initial study the agency did this spring testing 297 samples of commercial dairy productsall found to be negative for viable (live) highly pathogenic avian influenza (HPAI) H5N1 virus.
"The results of the study announced today strongly indicate that the virus is much more sensitive to heat treatment with commercial pasteurization equipment than other studies might suggest," said Stephen Walker, PhD, a consumer safety officer at the FDA's Center for Food Safety and Applied Nutrition (CFSAN), in an FDA press release.
The results of the study announced today strongly indicate that the virus is much more sensitive to heat treatment with commercial pasteurization equipment than other studies might suggest
The experiments used 275 raw milk samples obtained from multiple farms in four states currently experiencing H5N1 outbreaks among dairy cattle. Of the 275 samples, 158 were positive for viral fragments. Of those, 39 had infectious virus at an average of 3,000 virus particles per milliliter.
The samples were then subjected to "high-temperature-short-time" (HTST) or "flash pasteurization," the most commonly used US pasteurization technique. It consists of heating the milk to 161F (72C) for 15 seconds in a continuous flow. The researchers also contaminated some raw milk samples with a higher concentration of virus, 5 million virus particles per milliliter.
HTST eliminated the virus in all samples tested.
"While testing finished product post-pasteurization is one strategy to detect potential problems in finished products, validating the effectiveness of the pasteurization parameters critically demonstrates that commercial milk processing is capable of controlling the HPAI virus," said Nathan Anderson, PhD, also from CFSAN.
In related news, another new preprint study from researchers at Ohio State University, St Jude Children's Research Hospital, and the University of Illinois shows H5N1 avian flu RNA, but not live virus, in pasteurized retail milk.
The study found evidence of H5N1 viral nucleic acid in 36.3% of samples (61 of 168) from pasteurized milk bought from retail stores across the United States.
"None of the retail milk samples included in this study contained viable, infectious A(H5N1) virus per in vitro and in vivo assays, which provides evidence that pasteurization is sufficient for inactivation of pathogens in the commercial milk supply," the authors wrote.
Neither preprint study has been peer-reviewed.
Currently the USDA's Animal and Plant Health Inspection Service has detected H5N1 in 137 dairy herds from 12 states. Over the weekend the USDA confirmed new outbreaks in Colorado (3) and Iowa (1).
Ever since scientists discovered influenza infecting American cows earlier this year, they have been puzzling over how it spreads from one animal to another. An experiment carried out in Kansas and Germany has shed some light on the mystery.
Scientists failed to find evidence that the virus can spread as a respiratory infection. Juergen Richt, a virologist at Kansas State University who helped lead the research, said that the results suggested that the virus is mainly infectious via contaminated milking machines.
In an interview, Dr. Richt said that the results offered hope that the outbreak could be halted before the virus evolved into a form that could spread readily between humans.
I think this is good news that we can most likely control it easier than people thought, Dr. Richt said. Hopefully we can now kick this thing in the behind and knock it out.
The findings have yet to be posted online or published in a peer-reviewed science journal.
Seema Lakdawala, a virologist at Emory University who is researching the virus on dairy farms and was not involved in the new study, cautioned that breaking the transmission chain would require serious changes to how farmers milk their cows.
Its really great that these results are coming out, she said. But this is a real logistical problem.
We are having trouble retrieving the article content.
Please enable JavaScript in your browser settings.
Thank you for your patience while we verify access. If you are in Reader mode please exit andlog intoyour Times account, orsubscribefor all of The Times.
Thank you for your patience while we verify access.
Already a subscriber?Log in.
Want all of The Times?Subscribe.
AMA Update covers a range of health care topics affecting the lives of physicians, residents, medical students and patients. From private practice and health system leaders to scientists and public health officials, hear from the experts inmedicineon COVID-19, medical education, advocacy issues, burnout, vaccines and more.
Featured topic and speakers
What is dengue fever? Is dengue fever deadly? How long does dengue fever last? Can dengue fever kill you? Is dengue fever in Florida? Also, a bird flu 2024 update.
Our guest is AMA's Vice President of Science, Medicine and Public Health, Andrea Garcia, JD, MPH. AMA Chief Experience Officer Todd Unger hosts.
Unger: Hello, and welcome to the AMA Update video and podcast. Today, we have our weekly look at the headlines with the AMA's Vice President of Science, Medicine, and Public Health Andrea Garcia. I'm Todd Unger, AMA's chief experience officer. Good to see you again, Andrea.
Garcia: Good to see you, too.
Unger: Well, the last couple of weeks we've talked a lot about how climate change is driving extreme temperatures and the health impact of all of this heat. But this week, we've got something new that's driving concern and headlines, and that is dengue fever. Andrea, tell us what's going on there.
Garcia: Well, Todd, last week, we saw the CDC issue a health advisory, or a HAN, to physicians, public health authorities and the public, warning of an increased risk for dengue virus infections in the U.S. this year. This is really coming in response to an alarming number of cases we've seen abroad already in the first six months of 2024.
Countries in the Americas have reported more than 9.7 million dengue cases. That's twice as many as we saw in all of 2023. And in the U.S., Puerto Rico has declared a public health emergency this past spring because they've reported more dengue cases in the first five months of 2024 than all of last year. And those were during the dry season when dengue cases are typically at their lowest.
Unger: Andrea, have we seen any cases like this in the continental U.S.?
Garcia: Well, the CDC has said there's currently no evidence of a dengue outbreak in the continental U.S. We do see travel-related cases here. And since January, 745 dengue cases have been identified among U.S. travelers who became infected abroad.
That's higher than expected for this time of year, given that dengue cases typically increase during the warmest months, and we know those are yet to come. Public health officials are expecting to see the virus in more temperate regions, including the southern-most portions of the United States. The mosquito responsible for dengue is found in several states, including Texas, Florida and California. So far this year, Florida has already reported 10 cases from local spread and that is across four different counties.
Unger: So in effect, although we're not talking about necessarily the heat, this is an outcome of climate change, so to speak. Andrea, in terms of how it spreads, we know that dengue fever is spread through mosquitoes. But take us through a little bit more in detail about the mechanism there.
Garcia: So dengue is spread by the bite of an infected Aedes species mosquito, primarily Aedes aegypti, but it can also be spread by the Aedes albopictus mosquito.
Travelers infected abroad can then bring the virus back to their communities, where local mosquitoes bite them and then transmit the disease to others. According to the WHO, dengue is one of the world's most neglected tropical diseases. Three out of four cases are mild or asymptomatic, and that makes the illness really difficult to track.
Unger: And when you say Aedes, I don't think you mean the decade. That's A-E-D-E-S, for those of you who have not heard that term before. Andrea, talk to us about the seriousness of the cases that we're seeing right now.
Garcia: So most cases aren't serious, but there can be severe cases that lead to internal bleeding, organ failure or even death. Infections usually begin after an incubation period of about five to seven days, starts with a fever, and then it's accompanied by other symptoms, including nausea, vomiting, rash, muscle aches, joint and bone pain, pain behind the eyes, headache, or low white blood cell counts.
Unlike other diseases, where fever reduction is a sign that someone's getting better, for dengue, this is when the critical phase begins, and it typically lasts for 24 to 48 hours. There are several warning signs that indicate progression to severe disease. Those include abdominal pain or tenderness, persistent vomiting, bleeding from the nose or gums, and lethargy or restlessness.
Severe disease develops in about one out of 20 people with symptomatic dengue. And infants, pregnant people, adults over 65 years of age, and people with certain medical conditions are at an increased risk.
Unger: All right. Andrea, do we know what is driving this dramatic increase, you have to say, in the number of cases?
Garcia: Well, as you briefly mentioned, this is likely yet another byproduct of climate change. Soaring global temperatures have really accelerated the life cycles and expanded the ranges of mosquitoes that are responsible for dengue, helping spread that virus to roughly one in every 800 people on the planet in the last six months alone.
But it's not just rising temperatures. Climate-induced droughts can prompt people to stockpile water, which creates more mosquito habitats, and then it also escalates hurricanes and floods that produce standing water while simultaneously forcing people from their homes and increasing their exposure to mosquitoes. There was a Washington Post article that noted that, without drastic action to control the virus and slow climate change, research is suggesting that some two billion additional people across the globe could be at risk for dengue in the next 50 years.
Unger: Well those are pretty incredible numbers. And as you outlined before, in terms of symptoms, especially the more serious side, not good. Is there any kind of treatment available?
Garcia: Unfortunately, there are no antiviral medications approved to treat dengue and no vaccines for adults or people without a previous dengue infection. The only vaccine approved for use here in the U.S. is for children aged 9 to 16 years old who have had a previous dengue infection and who live in frequent or continued continuous dengue transmission area.
So think like American Samoa, Puerto Rico, U.S. Virgin Islands. But the supply of that vaccine is expected to run out after August of 2026. That's because the manufacturer is going to stop making it due to low demand. In May, the WHO expanded the use of a second vaccine, but that manufacturer withdrew its application from the FDA last summer because of data collection issues.
There's a third vaccine being developed by the NIH. It's still in clinical trials, and it won't be available in the U.S. for at least a few years. I think it's also worth noting that this disease is complicated because it's caused by four distinct but closely related dengue viruses. Infection with one dengue virus generally produces lifelong protection against infection from that specific virus but only partial and short-term protection against the others. And there's evidence that suggests the risk of severe complications may increase with sequential infections from a different type.
Unger: So Andrea, what should physicians be doing in response to this latest development?
Garcia: So the CDC is urging physicians to be on the lookout for dengue among people who have a fever and who've been in areas with dengue transmission within the last 14 days of the start of their illness. This disease is easy to miss, and since dengue hasn't been a problem here, awareness among physicians is likely low.
If physicians do suspect dengue, they need to order the appropriate diagnostic tests for acute dengue infection and of course report those cases to public health authorities. We can also do our part by using EPA-approved repellents, wearing loose-fitting long-sleeve pants and shirts to prevent getting bitten by mosquitoes in the first place. The CDC also suggests using air conditioning and window screens when possible and dumping and draining containers outside that hold water. And if you do develop symptoms, be sure to seek medical care.
Unger: All right. That is a great update on that and all good information, especially as we head into the hotter months. Andrea, let's switch gears a bit and do a quick check in on bird flu. Anything new happening there?
Garcia: Well we do continue to see rising cases. Last week we reported that we had been seeing 118 herds in 12 U.S. states with bird flu. This week, that number has grown to 132 herds. I think something worth talking about briefly are those agricultural fairs as we head into the holiday weekend.
Millions of people in the U.S. attend fairs each year, especially around the fourth and throughout the summer months. The CDC's recommendations around fairs previously focused on reducing the risk of spreading swine-origin flu viruses between pigs and people. Those recommendations have now been expanded to include cattle. The best thing people can do is avoid animal exposures at these fairs and remember to wash your hands frequently.
Unger: All right. There was also a new study that I read about that was promising news for containing the virus. Andrea, can you tell us a little bit more about that?
Garcia: Well, one of the big questions that scientists have been wrestling with is how this virus spreads from one animal to another. And there was a detailed article in The New York Times around a small experiment that was carried out in Kansas and Germany, which has offered some new information. Now, I think it's important to note these findings haven't been posted online or published in a peer-reviewed journal yet.
But what that experiment found is that the virus is mainly infectious via contaminated milking machines. And this certainly poses logistical problems for dairy farmers. But it would mean the virus is easier to contain than if it were spread through respiratory droplets.
According to a scientist involved in the study, this offers hope that the outbreak could theoretically be halted before it evolves into a form that can spread readily between humans. There are certainly caveats, though. These results are from two experiments that involved a very small number of cows.
The scientists also studied an early strain of the virus, and we know that virus has been mutating as it has moved from animal to animal. And researchers can't say whether a more recent strain would behave more like a respiratory disease. Certainly, though, Todd, this is something we'll continue to pay attention to.
Unger: Well, that's something we'll continue to watch carefully in the coming weeks. Andrea, that's all we have time for this week. I want to say thanks again for being here and sharing this important information.
I do want to add that we also have a lot of vaccine updates following the CDC's Advisory Committee on Immunization Practices meeting last week, but we'll be diving into more details on that on Monday with the AMA's ACIP liaison, Dr. Sandra Fryhofer. So make sure to tune in for that.
If you found this discussion valuable, you can support more programming like it by becoming an AMA member at ama-assn.org/join. And due to the Fourth of July holiday, this is going to be our last episode until Monday. Of course, you can always find all our videos and podcasts at ama-assn.org/podcasts.
Please enjoy your Fourth of July holiday. Stay safe out there. Take care.
Disclaimer: The viewpoints expressed in this video are those of the participants and/or do not necessarily reflect the views and policies of the AMA.
Get videos with expert opinions from the AMA on the most important health care topics affecting physicians, residents, medical students and patientsdelivered to your inbox.
Today theCenters for DiseaseControl and Prevention (CDC) confirmed thefourth human case of highly pathogenic avian flu in the United States this year and the first in Colorado, as the state reported more infected dairy cows. Previous human cases were in Texas (one) and Michigan (two).
In a press release emailed to journalists, the CDC said the Colorado patient is a dairy worker who was being monitored because of work exposure to H5N1 virus-infected cattle.
"The person reported eye symptoms only, received oseltamivir [Tamiflu] treatment,and has recovered," the CDC said. "Based on the information available at this time, this infection does not change CDC's current H5N1 bird flu human health risk assessment for the U.S. general public, which the agency considers to be low."
This infection does not change CDC's current H5N1 bird flu human health risk assessment.
The first two agricultural workers infected in the United States, in Texas and Michigan this spring, also reported eye symptoms.
The US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) has added two more H5N1 avian flu dairy herd outbreaks to its confirmed list, both in Colorado, raising its total to 139 affected herds from 12 states.
Colorado has had the most affected herds in the past 30 days, with 23 herds affected, APHIS said.
APHIS also reported H5N1 in 2 more domestic cats since our last report, 1 each in Michigan and Colorado, raising the total to 30 infected cats.
A WOAH (World Organization for Animal Health) notification on the Colorado cat, which is from Adams County, says the cat was exhibiting acute respiratory signs but wasn't associated with any known H5N1-affected cattle or poultry premises.
As more dairy herds have been infected with highly pathogenic avian flu, researchers from the Food and Drug Administration have continued to sample commercial pasteurized milk and conduct experiments that reassure consumers that the pasteurization process used in the United States inactivates H5N1. It is not yet known if drinking raw milk from an infected cow could pass H5N1 to humans, but mouse studies suggest it is possible.
A new survey from the Annenberg Public Policy Center, however, shows that less than half of US adults know that drinking raw (unpasteurized) milk is riskier than drinking pasteurized milk. The survey included 1,031 adults polled from June 7 to June 10. While only 4% of Americans report regularly consuming raw milk products, selling such products is legal in 30 states.
One in five Americans (20%) said they are not sure if pasteurization can kill harmful bacteria and viruses. And 4% of those polls said pasteurization is simply not effective in doing so.
In the poll, over half of the respondents (54%) think that drinking raw milk is either safer (9%) or just as safe (15%) or are unsure (30%) whether it is more or less safe than drinking pasteurized milk. Pasteurization does not lower the nutritional value of milk, but 16% polled believe that it does destroy nutrients, and 41% aren't sure.
Outside of H5N1, raw milk is estimated to cause 840 times more illnesses and 45 times more hospitalizations than pasteurized products, according to the Annenberg Center.
It is important that anyone planning to consume raw milk be aware that doing so can make you sick and that pasteurization reduces the risk of milk-borne illnesses.
"It is important that anyone planning to consume raw milk be aware that doing so can make you sick and that pasteurization reduces the risk of milk-borne illnesses," said Patrick E. Jamieson, director of the Annenberg Health and Risk Communication Institute at the Annenberg Public Policy Center (APPC) at the University of Pennsylvania.
Note: This story was updated at 1:40 pm Central Time with information on the human case.
More Videos
Next up in 5
Example video title will go here for this video
Next up in 5
Example video title will go here for this video
The U.S. Department of Agriculture recently updated their emergency assistance for livestock, honeybees and the farm-raised fish program.
Author: wzzm13.com
Published: 5:47 PM EDT July 4, 2024
Updated: 5:47 PM EDT July 4, 2024
In a recent study published in the United States (U.S.) Centers for Disease Control and Prevention (CDC)s Emerging Infectious Diseases Journal, researchers investigated the persistence of the highly pathogenic hemagglutinin 5 neuraminidase 1 (H5N1) avian influenza A virus from cattle and the H1N1 human influenza pdm09 pandemic virus strain in unpasteurized milk and on the surfaces of milking equipment.
Research Letter: Persistence of Influenza H5N1 and H1N1 Viruses in Unpasteurized Milk on Milking Unit Surfaces. Image Credit:OULAILAX NAKHONE/ Shutterstock
The highly pathogenic H5N1 avian influenza A virus was detected in domestic cattle in March 2024, followed by the virus outbreak in large herds in numerous states in the U.S. and at least three confirmed infections in humans. Analysis of unpasteurized milk samples confirmed the presence of high virus levels in milk, suggesting that dairy workers exposed to unpasteurized milk were at a high risk of being infected by the H5N1 avian influenza virus.
Furthermore, an increase in the number of human infections of H5N1 could also give the virus opportunities to evolve and adapt to the human host, increasing the potential human-to-human transmission rates. Although the milking process in the dairy industry is largely automated, there are some stages where human inputs are required, which could increase the workers risk of exposure to the highly pathogenic H5N1 avian influenza A virus.
In the present study, the researchers analyzed whether the highly pathogenic H5N1 avian influenza A virus and the H1N1 human influenza pdm09 pandemic virus strain could persist in unpasteurized milk droplets on the surfaces made of stainless steel or rubber such as the ones found in milking units.
One of the steps during the milking processes where human input is required is forestripping, where the teats in the vacuum units are manually expressed for the first three to five streams of milk. This process removes bacteria and allows the workers to check for any abnormalities in the milk. However, it results in milk splatter on surrounding surfaces and exposes the workers to unpasteurized milk that could potentially contain the highly pathogenic H5N1 avian influenza A virus.
Milk splattering or spraying could also happen during other stages of the milking process. Furthermore, the workspace in which the dairy workers interact with the cows puts the human eye level closer to the cows' lower regions, allowing droplets of potentially infectious milk to come in contact with the mucus membranes of the humans.
In this study, the researchers diluted strains of the highly pathogenic H5N1 avian influenza A virus or the surrogate H1N1 human influenza pdm09 pandemic virus strain in a 1:10 ratio using unpasteurized raw milk and pipetted droplets of this dilution onto rubber and stainless-steel surfaces inside an environmental chamber.
A tissue culture assay was used for endpoint titration to detect the presence of the virus at zero, one, three, and five hours. The experiments were conducted at 70% humidity to mimic the open-air environmental conditions in the milking parlors between March and April 2024 in the Texas panhandle region, which is when and where some of the outbreaks occurred.
Illustration of milking unit surfaces tested in a study of persistence of influenza H5N1 and H1N1 viruses in unpasteurized milk. Before attaching the milking unit (claw), a dairy worker disinfects the teat ends, performs forestripping of each teat to detect abnormal milk, and then wipes each teat with a clean dry towel. Workers then attach the milking unit to the cow teats. A pulsation system opens and closes the rubber inflation liner (at left) around the teat to massage it, mimicking a human stripping action. A vacuum pump is controlled by a variable speed drive and adjusts the suction to allow milk to flow down a pipeline away from the cow into a bulk tank or directly onto a truck. Additional sources of exposure to humans include handling of raw unpasteurized milk collected separately from sick cows or during the pasteurization process. Schematic created in BioRender (https://www.biorender.com).
The study found that the highly pathogenic H5N1 avian influenza A persisted in the droplets of unpasteurized milk on the rubber and stainless-steel surfaces and remained infectious for over an hour. In comparison, the H1N1 human influenza pdm09 strain dropped below the detection limit in less than an hour.
However, the viral decay rates for the H5N1 and the H1N1 viruses were similar on stainless-steel and rubber surfaces, indicating that the H1N1 human influenza pdm09 strain could be used instead of the H5N1 cattle virus to study the persistence of the virus in raw milk samples.
Longer observational experiments indicated that the H1N1 pdm09 strain persisted on the rubber surface of the inflation liner used in the milking process for over three hours, while on the stainless-steel surfaces, it persisted in droplets of unpasteurized milk for at least an hour.
These results showed that the highly pathogenic H5N1 avian influenza A virus that has now infected domestic cattle can persist in unpasteurized milk and can remain infectious for over three hours inside droplets of milk splattered on surfaces during milking.
Currently, no respiratory or eye protection has been required for dairy workers, but the CDC has released recommendations for face shields, eye protection, masks, and other personal protective equipment. Sanitization of the rubber inflation liners is also recommended to prevent the spread of the virus among the cows.
To summarize, the recent outbreak of the highly pathogenic H5N1 avian influenza A virus among domestic cattle poses a serious risk of infection to dairy workers exposed to droplets of unpasteurized milk. The study found that the virus can persist and remain infectious in droplets of unpasteurized milk splattered on the surfaces of milking equipment for over three hours. The researchers recommend the use of protective equipment during milking and the sanitization of the milking equipment to prevent viral transmission among humans and animals.
Journal reference:
