Bird flu: how serious is it really?
After 133 known US human cases, there was finally a death this weekend. A Canadian teen went from pink eye to life support in 4 days, and a researcher says we're at Defcon 1. How real is it?
For now, the risk to people remains low, but the longer it lingers, researchers become more concerned about the possible mutations that could make it easier to transmit among humans and have a greater impact on human health. In this post and another, I’ve tried to put together information from, and links to, multiple sources.
What is it? What are the symptoms? Treatment?
How is bird flu spread?
Just about every possible way: inhaling droplets or infected dust; touching surfaces with viral droplets; contact with infected animals or their body fluids (saliva, feces); eating undercooked (<165°) eggs or meat from infected poultry; or drinking raw (unpasteurized) milk from infected dairy cows. Think COVID prevention plus extra caution with poultry, and avoiding drinking raw milk or serving raw milk to animals and pets.
Is it new?
No – avian flu was actually first identified in 1878. The current outbreak started in Europe in late 2020, quickly spread worldwide, and picked up significantly in 2024. Here’s a summary timeline. Key 2024 US dates:
March: First reported US dairy cow infections
April: First confirmed US human case of bird flu
November:
Egg prices rose due after culling of infected poultry flocks
A child was infected in San Francisco without any apparent contact with poultry or cows, but who did test positive for several other respiratory viruses
December:
An otherwise healthy 13-year-old in Canada went from early symptoms—conjunctivitis, or pink eye—to life support in four days. She is expected to survive. Worryingly, like the Louisiana patient, she did not appear to have been exposed to infected cattle or poultry, elevating concerns about other modes of infection or human-to-human transmission, although no one exposed to them became ill.
The first recall of frozen raw cat food leading to cat death, followed by another in early January, indicating freezing along does not destroy the virus
The FDA began testing cheese made from raw cow's milk over concerns it might be contaminated with bird flu.
January 2025
In the US, we reached outbreaks in poultry in 50 states and in over 900 dairy cattle herds
Finally, after 66 US cases reported in 2024, the first US death occurred in an at-risk Louisiana man who had both wild birds and a “flock” of some so-far undisclosed type on his property. See more below.
See the CDC Current Situation report here.
How dangerous is it?
In over 900 reported cases worldwide, bird flu killed about half of the people known to have been infected—but keep in mind many infections may have been mild and not diagnosed or reported. In the US, testing increased since 2022, although many scientists are concerned we’re not doing enough, including the physician researcher who says we’re at “Defcon 1.” You’d think we would have learned from COVID, but there are indications we might not have, despite the USDA pouring almost $2B into combatting avian flu since 2002. If we haven’t, lack of interdisciplinary coordination among department silos will most likely be at fault. As in health care, one specialty alone no longer is usually adequate for dealing with anything serious.
What we do know is that as of Jan 6, 2025, there were 133 confirmed US cases in humans since 2002, about half of which—66—were in 2024. Of those 133 known US cases, the Louisiana case was the first known death.
What do we know about the Louisiana death?
You’ll remember from COVID that those >65 with preexisting conditions were at higher risk; that’s generally the case with most significant diseases. This man was reported to be in that category. Importantly, he was also had known exposure to a “combination of a non-commercial backyard flock and wild birds.”
The word “flock” typically refers to birds like poultry or other birds (like ducks), although it can also refer to sheep or goats. The nurse in me is uneasy the type of “flock” has not been described in detail in press releases. Here is the notice from the Louisiana Department of Health, and here is the CDC notice.
One concern is that gene sequencing from the patient identified mutations that were not found in poultry on his property, suggesting the mutations occurred in the patient after he was infected. That may have been the case in the Canada case as well, and it’s mutations that concern scientists. At a commonsense level, from five years of COVID, we’ve seen mutations in action in relationship to varying degrees of symptoms and contagion. The good news is that so far there is no evidence of human-to-human transmission. In both the Canadian and Louisiana cases, others around them did not become ill.
Are some people more at risk than others?
If you live in an area where testing indicates increased bird flu activity, have pre-existing conditions, and/or particularly if you have job-related or recreational exposure to birds or animals, you’re at greater risk. Here are current general CDC recommendations on protecting yourself. If you’re in farm or poultry work, here are more specific recommendations. Monitor these sites for changes in recommendations.
What are the symptoms?
Prior to the Louisiana and Canadian cases, most N. America cases have been mild. Symptoms are like any other flu, except for one: conjunctivitis, or pink eye. That should be a flag particularly if exposure to meat or poultry is potentially involved. If you have pink eye, definitely tell your provider if you may have been exposed to poultry or animals. You’ll be tested with a swab from your nose, throat or eye, and an antiviral may be prescribed while further testing continues.
How do I prevent getting it?
Get this year’s flu shot. While it won’t directly prevent bird flu, it can reduce your risk of serious illness and of getting both bird flu and seasonal flu at the same time, since one infection lowers resistance to another. You’ll also help all of us stay safer: mutations happen faster when other infections are present. Particularly to the old and young among us, bird flu complications are dangerous. They can include pneumonia, acute severe respiratory distress, sepsis, meningoencephalitis and respiratory failure, like the teenager in Canada experienced.
Make sure eggs and poultry are cooked to 165°
Don’t touch or drink unpasteurized (raw) milk or feed it, or raw meat, to your pets
Be very careful handling raw meat. Don’t wait for a recall; remember it takes a huge amount of data, and time, to establish the need for a recall. Be suspicious now. Wear gloves when handling raw meat. And keep in mind freezing doesn’t seem to reduce the virus (see more above on cat deaths after eating raw [meat] cat food that had been frozen).
Be cautious about visiting areas with animals or poultry, like markets or farms and petting zoos, or areas with water features with geese or ducks, both of which have been found to carry bird flu. If you do visit these places, wear a well-fitting mask, remove your shoes before entering homes (and disinfect them), and wash your hands carefully for at least 20 seconds. Hand sanitizer helps but isn’t as good as hand washing.
Wait – do I need to worry about the wild birds I’m feeding?
I love wild birds. There’s not much on this topic specifically, so I did a deep dive. It’s long, so see the separate post. Short version: Yes, you should be thinking about it. I am.