Bird Flu Recently Spread to Dairy Cows in the US

As of June 6, three dairy farm workers in the US have contracted the virus from cows—two from different facilities in Michigan and one in Texas. Naturally, this raises concerns: Should we worry about catching this virus? Is another pandemic on the horizon?

Experts are worried about the US’s ability to control bird flu and prevent its spread among people. There are issues like insufficient USDA guidance on quarantining infected cows, limited monitoring of exposed farm workers (many of whom are undocumented and reluctant to get tested), and a lack of funding to track high-risk individuals. Public health officials are trying to mitigate this by increasing wastewater surveillance and boosting lab capacity for testing and viral sequencing. Although we’re not facing a pandemic yet, there are concerns that current efforts might not be enough.

“The goal here is to use public health for containment so we never get to that place again. In order to do that, public health has to be really aggressive, and I’m not sure I’m seeing ramped up coverage.”H5N1 primarily affects wild aquatic birds like ducks, geese, and swans but is increasingly jumping to other species, according to Dr. Landon. Globally and in the US, cases have been detected in wild and domestic animals like foxes, cats, dogs, mice, tigers, leopards, sea lions, bears, skunks, and goats.

H5N1 was first identified in 1996, making it a well-studied virus. Over the past three decades, bird flu infections in humans have not surged, and there has been no evidence of easy human-to-human transmission. According to the CDC, about 890 people have been infected with H5N1 since 1997, averaging about 33 cases per year. This is minimal compared to the vast number of infected animals, Dr. Landon says.

Although bird flu has had a high mortality rate in humans over the last 30 years, recent cases in the US have shown mild symptoms. The first two individuals infected this year experienced eye problems, while the third had a cough and some eye discomfort.

Several factors might explain why people are experiencing mild symptoms despite the historically high death rate. Cows don’t get as sick as chickens, potentially leading to a lower viral load. The current circulating strain may be less harmful, or the farm workers infected might be generally healthier and have stronger immune systems.

“This virus still needs to change in order to be able to cause a pandemic, but we can’t predict how that change will happen and if it will get worse or better for the humans that get it.”

Bird flu symptoms—sore throat, runny nose, fatigue—are similar to those of other viruses, making it hard for doctors to determine who needs a test. However, public health officials are not testing as many exposed individuals as necessary, raising concerns about silent spread. On May 24, the CDC reported that “more than 350 people have been monitored as a result of their exposure to infected or potentially infected animals, and at least 39 people who have developed flu-like symptoms have been tested as part of this targeted, situation-specific testing.”

You can also get bird flu from raw milk. Dr. Landon says this is a significant concern as more people consume raw milk for its purported health benefits. The pasteurization process, which raw milk doesn’t undergo, kills harmful bacteria and viruses like the bird flu. The FDA states that nearly 99% of the commercial milk supply is pasteurized, but raw products sold by local farmers in several states may contain H5N1 or other dangerous pathogens like salmonella, E. coli, Listeria, and campylobacter. A recent FDA survey of 297 samples of pasteurized dairy products from retail stores in 17 states found some contained bird flu traces, but further testing showed the virus was not live or infectious—meaning pasteurization worked. Raw dairy products, however, may contain live viruses and bacteria.

Getting bird flu from eating chicken, turkey or beef is highly unlikely if properly cooked. Food safety experts advise cooking poultry to an internal temperature of 165 degrees Fahrenheit and beef between 145 and 165 degrees Fahrenheit. A recent USDA investigation of 109 beef samples found one positive for H5N1, but it didn’t enter the food supply. Even if it had, cooking would have killed the virus. Other tests on ground beef samples from grocery stores in states with bird flu outbreaks in cows found no evidence of the virus.

The CDC recommends that anyone who might handle potentially infected birds get a regular flu shot a couple of weeks in advance.

Common backyard birds like robins, blue jays, sparrows, cardinals, and pigeons typically don’t carry bird flu viruses. However, avoid touching wild birds as they might not appear sick when they are. “If a bird runs into your window and falls on your balcony, don’t try to save it and document it on TikTok,” Dr. Landon says. “At least not right now.”