Bird Flu Frequently Asked Questions: H5N1 Dairy Cow Outbreak in Texas, New Mexico, Michigan

The excellent news — at the very least for now — is that public health experts don’t expect this latest bout of bird flu to evolve into anything just like the coronavirus pandemic. However, provided that the disease has spread to poultry in 48 states, dairy cows in nine states, and two people in Texas and Colorado, you might be concerned concerning the potential impact in your health.

Assets spoke with a trio of epidemiologists who, below, answer necessary public health questions on bird flu.

What is bird flu?

The variety of bird flu currently circulating is one Highly pathogenic avian influenza (HPAI)– a disease that may severely affect wild and domestic birds and poses a significant threat to the poultry industry and subsequently the worldwide economy, in response to this US Department of Agriculture (USDA). The other type, low pathogenicity avian influenza, causes mild infection in wild birds but can transform into HPAI in poultry.

Influenza viruses are divided into 4 types, A, B, C and D, explained Edwin Michael, PhDan epidemiologist University of South Florida College of Public Health. What we call seasonal flu in humans is brought on by types A and B. Bird flu falls under the umbrella term of influenza A viruses. The strain currently circulating within the United States is H5N1, an HPAI named for proteins on the surface of the virus.

“It can spread very quickly through the bird population – wild birds. That can spread it all over the world,” says Michael Assets. “The virus is excreted from the bird through mucus, saliva and feces and can then get into domestic poultry.”

When HPAI strains reach domestic poultry, they’ll kill entire flocks inside days, the USDA says. Birds with HPAI infection may exhibit a variety of symptoms including diarrhea, lack of energy and appetite, and a decrease in egg production. Since HPAI can’t be treated, clearing the poultry population is the one solution.

Such a cull could be effective in curbing the spread of birds critical to U.S. agriculture and food production, it says Dr. William Schaffnera professor within the Division of Infectious Diseases at Vanderbilt University Medical Center.

“This special bird flu virus in its variants has actually been around for a long time – over a decade,” says Schaffner Assets. “It has spread gradually, but recently its spread around the world has become much more evident and widespread for reasons that I at least do not understand.”

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How does bird flu spread to humans and other mammals?

Because of its segmented DNA, H5N1 is a shape-shifter, so to talk, explains Michael.

“For example, if a person is infected with bird flu and is also a carrier of the human influenza A virus, these two viruses can exchange genetic material. This is known as genetic shift“ says Michael. “This can result in completely new viruses [and] cause epidemics.”

However, flu pandemics are rare and occur about thrice a century, says Michael. Perhaps probably the most notable is the so-called “Spanish Flu” of 1918–1919because the Centers for Disease Control and Prevention (CDC) estimated that “an avian-like H1N1 virus” killed 50 million, possibly as many as 100 million, people worldwide.

You probably remember this Swine flu pandemic 2009, brought on by a previously unknown H1N1 virus that contained pig, human and bird genes. How did that occur? Because bird flu viruses don’t all the time spread effectively amongst humans, they often need the assistance of other species to thrive, Schaffner explains.

“The pig’s respiratory tract is designed to cope with bird flu infections and –And–Infections with a human virus,” says Schaffner. “You could think of the pig as a test tube that gets a bird flu and a human flu, and if that happens at the same time in the same pig, then those two viruses come together and can have the ability to exchange genetic elements.”

Although the most recent H5N1 strain shouldn’t be known to be spreading amongst humans, it has already spread to greater than a dozen wild mammal species, from black bears to bottlenose dolphins. As recently as May 3, red foxes in New York and Michigan tested positive USDA Animal and Plant Health Inspection Service (APHIS)..

“This bird flu virus does not rely on pigs, but rather mutates on its own to become a more effective infection in a variety of different mammal species,” Schaffner says. “What was in the news is dairy cattle, which surprised every virologist.”

When was bird flu last seen within the United States?

Government authorities monitored this recent bird flu outbreaks since January 12, 2022, as a Northern Shoveler A duck in Hyde County, North Carolina tested positive for a Eurasian H5N1 strain.

The disease had spread all over the place in wild birds greater than 1,100 counties As of May 8, 2024, infected almost 9,400 poultry.

The situation is even worse US poultry. As of May 7, there have been nearly 91 million birds, including industrial poultry and backyard flocksHe had develop into infected. This includes greater than 1,100 outbreaks in 522 counties in 48 states.

APHIS recorded this first poultry infection in a industrial turkey flock in Dubois County, Indiana, on February 8, 2022.

Although H5N1 has been circulating in wild birds, domestic poultry, and mammals nationwide since 2022, this is the reason you’ll have only recently heard about it Jump to dairy cattle. The first positive case was documented in Texas on March 25, 2024.

By May seventh there have been almost 40 dairy herds infected in nine states.

The logistics of recent industrial agriculture might be fueling the spread of H5N1 to cattle, says Michael.

“Look at the density of animals on these farms – these are not natural environments,” says Michael Assets. “So as soon as you come [an infection]these things will spread very quickly among livestock.”

Michael adds: “We need to shine a light on the way farming is done. That’s the trade-off: you want cheap meat and everything else, but then when you raise animals that way, you open the door to other things.”

Is it secure to drink milk and eat chicken?

The Food and Drug Administration (FDA) acknowledges that the emergence of avian influenza in dairy cows is “a novel and evolving situation”. However, no studies have been conducted on the results of pasteurization – a sterilization procedure that kills harmful bacteria – on HPAI in bovine milk. However, the FDA states that existing research has supported its understanding and conclusion that milk consumption is secure.

The FDA and USDA are conducting a nationwide industrial milk sampling study that features milk-derived baby foods. As of May 1, HPAI has not been detected in any of the formula products. While bird flu appeared in milk, sour cream and cottage cheese samples, the virus was inactivated by pasteurization.

“To milk, eggs, [and] “Chickens as a source of infection,” says Schaffner Assets. “I’m out there drinking milk and we had chicken for dinner last night.”

Both Schaffner and the FDA urge the general public to avoid raw, unpasteurized milk. The CDC recommends Cooking eggs and poultry heated to an internal temperature of 165 degrees to kill bacteria and viruses, including H5N1.

How anxious must you be about H5N1 affecting people?

Simply put: Don’t panic, he says Michael Osterholm, PhDDirector of the Center for Infectious Disease Research and Policy on the University of Minnesota.

“At this point there is no evidence that this poses an immediate danger to humans,” says Osterholm Assets. “We haven’t observed any transmission to humans to suggest that that is the following pandemic virus.

“On the other hand, a repeat event or persistent mutations could occur tomorrow.”

According to the CDC, two people have been infected with H5N1 to date. An individual exposed to dairy cattle in Texas tested positive on April 1, 2024 and an individual in Colorado involved within the killing of poultry tested positive on April 28, 2022. No person-to-person transmission was confirmed and the newer patient’s only symptom was Conjunctivitis or conjunctivitis.

“We have two or three receptor sites in our eyes, so a case of conjunctivitis would not be unusual,” says Osterholm. “There was no evidence of any type of respiratory infection, which is the key factor in severe illness and subsequent transmission of the virus.”

The Texas case is the primary time a human has been infected with H5N1 through contact with a mammal World Health Organization (WHO). Nevertheless, the WHO considers the general public health risk to the final population to be low. For farmworkers and other industrial staff more likely to be exposed to the virus, the chance is low to moderate.

Going forward, ensuring the health and safety of farmworkers is paramount to stopping the spread of H5N1 to the broader population, says Michael.

“I don’t think this will be a major outbreak (in humans),” Michael says. “[But] The risk is always there because of the way we treat nature.”

Further information on the recent bird flu outbreak: