Four years after the COVID pandemic first began, public attention has turned to another virus: highly pathogenic avian influenza A (also known as H5N1), which has been the center of a rash of outbreaks across dairy farms in the U.S. Even more worryingly, a few humans have also gotten sick.
But wait, isn't this a pathogen that only infects birds? Technically, it originated in birds, but as we've seen many times in the history of public health, some of the most problematic viruses jump from animals to us. The long list of so-called zoonotic transmissions includes Ebola, SARS-1, MERS, Lyme disease and most likely, SARS-CoV-2, the virus responsible for COVID-19.
Indeed, bird flu, as H5N1 is also known, has been around for a long time, and has infected plenty of humans before, often with deadly results. But thankfully, the virus hasn't caused widespread infections in humans yet. However, a global bird flu pandemic in birds and other animals has been causing chaos for over three years now, killing hundreds of elephant seals in Antarctica, spreading throughout mink farms in Europe, not to mention cats, and massacring untold millions of birds. It marks the worst bird flu pandemic in recorded history.
So far, this global bird flu crisis hasn't significantly translated to humans. But the fact that so many dairy farms lately are seeing outbreaks, which has spread to at least two people, has many worried that this crisis could intensify.
The first infected individual resides in Texas and is suspected of having made direct contact with an infected cow, according to the Texas Department of State Health Services. The patient's only symptom was eye inflammation. The infection, however, occurred after it was confirmed that cows were transmitting a new bird flu strain between themselves, which signifies the virus could be adapting to mammalian (as opposed to avian) hosts.
So how worried should you be? Here's what we know so far.
Where are bird flu outbreaks happening?
So far, 12 H5N1 outbreaks in dairy cows across at least six states have been confirmed, alarming health experts. The first cases appeared in Kansas and Texas, but were soon detected in Idaho, New Mexico and Michigan. On Thursday, Ohio became the latest state to become part of the growing outbreaks, with some officials anticipating that outbreaks will rise over the next few days.
Only weeks earlier, the same bird flu strain was detected in goats on a Minnesota farm where bird flu had previously infected the poultry. That was the first ever confirmed American case of bird flu being transmitted to livestock. The infected animals display symptoms such as lethargy, low appetite and decreased lactation. Outside of dairy farms, Cal-Maine Foods, Inc., the largest producer of fresh eggs in the U.S., was hit by a bird flu outbreak, resulting in the company culling 1.6 million chickens, approximately 3.6% of its entire flock.
The good news is that there is no indication that consumers are at risk of drinking bird flu-infected milk, according to US officials on Monday. At the same time, a spokesperson for the Centers for Disease Control and Prevention (CDC) still urges Americans to be careful.
"The best prevention is to avoid sources of exposure," the spokesperson said. "The best way to prevent avian influenza is to avoid sources of exposure whenever possible. Infected birds shed bird flu virus in their saliva, mucous, and feces. People rarely get bird flu; however, human infections with bird flu viruses can happen when enough virus gets into a person’s eyes, nose or mouth, or is inhaled."
What precautions should we take?
Dr. William Haseltine, a pioneer in fighting HIV/AIDS and chair and president of the global health think tank Access Health International, says that ordinary consumers should practice the same precautions that were widespread during the height of the COVID-19 pandemic. These include wearing masks in public places (especially airline flights), frequently and thoroughly washing one's hands when outside the house and stocking up in advance on the new anti-flu drug (Xofuza) to take when exposed.
As for the seasonal flu vaccine, Haseltine says "it isn't a good match for the cow-derived flu but the best that is now available."
Dr. Georges Benjamin, executive director of the American Public Health Association, told Salon that although most people are at a "very low risk" of getting infected unless they work around sick animals, "the best way to reduce your risk in general from respiratory diseases is to get your annual flu shot, cover of your nose and mouth when you cough or sneeze and wash your hands frequently."
"The annual flu shot will not protect you from bird flu but it does help in protecting you from coinfection with bird flu and theoretically would lead one to look for bird flu if you came down with flu-like symptoms and you had exposure risk factors," Benjamin added.
Benjamin also said that people should avoid uncooked and undercooked food, as well as unpasteurized milk or cheeses. "This is especially important if you go to farms, county fairs which have animals or petting zoos. Also stay at home of you are sick or have symptoms from a respiratory disease."
In a press release on Monday, the CDC said that Americans "should avoid unprotected exposures to sick or dead animals including wild birds, poultry, other domesticated birds, and other wild or domesticated animals (including cattle), as well as with animal carcasses, raw milk, feces (poop), litter, or materials contaminated by birds or other animals with confirmed or suspected HPAI A(H5N1)-virus infection."
Will H5N1 be the next pandemic?
While no one can predict the future trajectory of this virus, pandemics are a regular occurrence in our hyperconnected global economy (and regularly occurred even before the invention of capitalism.) It's only rarely in Western countries where an epidemic becomes severe enough to warrant the kind of response appropriate for COVID. Most people may not even recall the swine flu (H1N1) pandemic in 2011.
While all of these bird flu outbreaks are worrisome, the worst case scenario is in which human-to-human transmission becomes widespread. Presently it is unknown if that will happen. According to a spokesperson for the CDC, avian influenza A outbreaks occur in poultry throughout the world and in North America from time to time. In the United States there was an H5 outbreak in 2014-2015, an H7N8 outbreak in 2016, an H7N2 outbreak in cats in 2016 and an H7N9 outbreak in 2017.
Another concerning detail about the disease is that cow-to-cow transmission has been confirmed. which indicates "transmission can occur to other animals including birds and people. In that process the virus can mutate and become more virulent and/or infectious," Benjamin said. "When this happens, serious outbreaks can occur that can cause severe illness."
Benjamin described the confirmed fact of human infections as "a red flag that tells us we need to step up our disease surveillance and our infection control efforts for at risk animals and people."
