If you’ve struggled to find eggs in the grocery store recently, you’ve seen the effects of highly pathogenic avian influenza, also known as “bird flu” or H5N1. When chickens get sick with this disease, they’re killed to prevent transmission, so fewer eggs are on the market.
“It’s a consequence of a good strategy that prevents spread of the virus,” says UNC Health infectious diseases specialist David Wohl, MD. “Enormous numbers of chickens have been culled because this is so widespread in birds right now. It’s unfortunate, but it’s part of an effort to be hypervigilant and catch this early.”
Unfortunately, bird flu is no longer limited to just birds. It has spread to other species, including humans, sparking concerns that we are heading for another pandemic.
“The good news is, it has not spread from human to human yet,” Dr. Wohl says. “We have time to make sure that we’re prepared for it, but we do need to respect that it’s a matter of time. It’s not will this happen, it’s when will it happen, but we can prepare now.”
Here are six facts to know about bird flu.
1. Bird flu has not spread from person to person yet, but scientists expect it will.
H5N1 is a subtype of influenza A that started in birds and has spread to mammals, including humans. So far, the people who have contracted bird flu have gotten it from animals, not from other people.
“More than 500 individual species have had this virus detected, from polar bears to cows,” Dr. Wohl says. “We interact with some of these infected animals on a regular basis, particularly chickens and cows on farms.”
There have been about 1,000 cases of the virus in people outside the United States, and about half resulted in death. In the U.S. there have been close to 70 human cases and one death. So far, these cases have, with a few exceptions, involved people who worked on farms or directly with farm animals.
Because viruses adapt to infect as many hosts as possible, scientists are concerned bird flu will evolve and gain the ability to spread from human to human.
“Then it becomes a different ball game,” Dr. Wohl says. “If the virus evolves and/or borrows genes from other viruses, we might see increased spread of a new version of the virus that we do not have immunity to.”
2. Red eyes are a telltale sign of infection.
So far, most people with documented cases of bird flu have had mild symptoms that you would associate with a cold or standard flu—fever, cough, runny nose, sore throat and nasal congestion—and one telltale symptom: red eyes.
“More than 90 percent of cases have had conjunctivitis,” also known as pink eye, Dr. Wohl says. “If you work on a farm, have symptoms of acute respiratory illness and have red eyes, that should be a tip-off for you or your provider.”
While we’re in the midst of a difficult flu season, Dr. Wohl says that bird flu is still largely limited to people with direct exposure to farm animals—mostly agricultural workers, though some cases affected people with backyard flocks.
“The chances of the average person with sniffles or respiratory illness having this are really low right now,” Dr. Wohl says.
Current tests for seasonal influenza detect the presence of influenza A, so if a provider suspects a person has bird flu and influenza A is present, further testing to confirm the subtype can be done. While waiting for confirmation, treatment can begin.
“Given the severity potential, the patient should start antiviral therapy early,” Dr. Wohl says. “Right now, oseltamivir or Tamiflu will work against this virus. Hopefully, this treatment will continue to work and the virus won’t develop resistance to it.”
3. Eggs are safe to eat.
While there are fewer eggs available right now, Dr. Wohl says the ones in the store are safe to eat.
“Sick chickens don’t lay eggs very well,” he says. “The way eggs are formed, there is little opportunity for the virus to get into the egg, and most people cook eggs, which also helps to kill the virus.”
4. Pasteurized milk is safe to drink.
While there has been testing of chickens for bird flu, Dr. Wohl says the testing of cows has been less widespread, and infected milk and the industrialized milking process could be causing spread between cows.
Pasteurization kills the virus, if it is present, as well as other pathogens, including E. coli, salmonella and listeria.
“We’re not worried about milk or dairy products that are pasteurized,” Dr. Wohl says.
Some people drink raw milk, which is not pasteurized, because they believe it has health benefits. Published research has disputed this, and now is not the time to take a chance, Dr. Wohl says.
“Even if you thought there was a benefit before, unpasteurized milk is now a bad idea,” he says. “You risk illness for yourself or your child. The risk to perceived benefit analysis has to change now that cows are becoming infected and this virus is spreading.”
5. There is a bird flu vaccine.
The United States has a stockpile of a H5N1 vaccine in case of emergency, Dr. Wohl says; the current flu vaccine, while a good idea for protecting against seasonal flu, does not protect against H5N1. However, there are concerns that if the virus evolves, the stockpiled vaccine will no longer be a good match for the virus and might not work as well.
“We learned from the COVID-19 pandemic that mRNA technology could be used to ramp up creation of a vaccine better matched to what’s circulating, if this becomes a bigger problem with more transmission,” Dr. Wohl says. “We have to be willing to use the technology at hand, and we have to be thoughtful about supporting a strong public health infrastructure that will be robust enough to be aware and respond.”
6. Now is the time to prepare for more bird flu cases.
Most people don’t have to take special precautions to prevent bird flu right now. Farm workers are an important exception; they should use personal protective equipment, or PPE, when in contact with animals and report any symptoms of bird flu to their doctor.
Pet owners should keep their dogs and cats away from dead animals, especially birds.
Healthcare providers and hospitals are planning for when cases increase, Dr. Wohl says. It’s important to pay attention and not let pandemic fatigue win out, he adds.
“Viruses don’t care how tired or fatigued you are or if you don’t like masks or needles,” Dr. Wohl says. “If this spreads as we predict, then people will get sick, and of those, some will get really sick or die. I don’t think this will be like COVID-19, because we are already better prepared with medications, vaccinations and the ability to ramp up improved vaccines. But we can’t ignore this risk, and we have to plan.”
Concerned about respiratory symptoms? Talk to your doctor. If you need a doctor, find one near you.