Last Friday, the Missouri Department of Health made a recent announcement Bird flu in humans. What’s disconcerting about the case is that the patient — admitted to the hospital on August 22 and later discharged — is the first of these 15 people have been infected in the United States Those who did not report contact with animals. This raises the possibility that the illness has already begun to spread among humans.
It is not yet clear whether the virus is involved H5N1 influenza subtype which has infected wild birds, poultry and dairy cows worldwide since it was first detected in 2020, and has raised flags among experts about another possible pandemic. If this is the case, however, there are concerns about what the Missouri case may represent. “There are several steps before it becomes a potential pandemic threat,” said Nahid Bhadeliawho directs the Boston University Center on Emerging Infectious Diseases. “But I’m a lot more worried about that than I am.”
For most people, the threat of bird flu is low. Still, here’s what the experts make of the case and what you can do to protect yourself.
What experts are concerned about
The Missouri patient was ill enough to be hospitalized
Since the virus first appeared in American dairy cows in January of this year, there have been 13 cases of bird flu detected in humans before last Friday. Very mild disease — Redness of the eyes, otherwise known as conjunctivitis, and in one, cough without fever.
That’s where the last case is different: the patient was admitted to the hospital, a serious illness was suggested. The Missouri Department of Health noted that the adult patient “has an underlying medical condition,” but we don’t know their age or other risk factors.
A flu virus to cause a human pandemic, says Seema LakdawalaA virologist and flu expert at Emory University, it must overcome three hurdles: It must enter the respiratory tract and replicate efficiently to cause disease; It must spread easily from person to person; And it has to be novel for our immune system. If the virus contracted in a recent case turns out to be H5N1, the fact that the patient was hospitalized indicates that the virus is evolving to replicate more efficiently in our airways (and is getting closer to crossing the first barrier).
We don’t know how the Missouri patient was infected
Another thing that all previous US human H5N1 cases have shared is that they can be Trace back to close contacts with infected farmed poultry or dairy. That link doesn’t seem to exist in this case.
Spread through casual contact — for example, between people standing next to each other on a bus — has not been reported with the virus and would be even more worrisome.
Without known exposure to an infected animal, there are concerns that H5N1 could spread in other ways – for example, through drinking raw milk or, more consequentially, from person to person, which could lead to much larger outbreaks.
Some spread among family contacts or from sick patients to health care workers has occurred with H5N1 in the past, but has not been sustained, said Jennifer Nuzzois an epidemiologist who leads the Epidemiology Center at Brown University’s School of Public Health. However, spread through casual contact – for example, between people standing next to each other on buses – has not been reported with this virus and would be of greater concern.
For an epidemic spreading through casual contact would represent a step toward overcoming Lakdawala’s second hurdle: sustained person-to-person transmission. “The last time a flu virus did this, which was 2009, it was around the world in a matter of days,” Nuzzo said.
It is a promising sign that since the Missouri patient was admitted to the hospital, there There hasn’t been a big bloom of flu-like illness in the state. “I don’t think there’s a whole iceberg that we can’t see,” Nuzzo said, but more details about the case would put him and other experts at ease.
Infection through raw milk would also be bad news. Although most U.S. milk supplies are pasteurized — that is, heated in a way that kills bacteria and viruses — 1 in 100 Americans surveyed in the late 2010s said they Drink raw milk every week. We still don’t know if the person who got infected in Missouri was a raw milk consumer, but that’s much more likely than the option of person-to-person spread, Vadelia said. It’s easier to control what you eat and drink than who you interact with.
Two weeks elapsed between the patient’s hospitalization public health of authority announcement About the case
That long delay, Nuzzo said, suggests the U.S. hasn’t rolled out its sensitive flu surveillance system that would have more quickly detected bird flu infection in people with fever, cough, muscle aches and other flu-like symptoms.
If there is a lot of person-to-person spread, putting that system in place means detecting that spread early — perhaps at a stage when it can still be contained. If the system isn’t activated, however, the infection in humans can get out of hand before we have a chance to stop it using vaccines and drugs that we know work to prevent severe flu symptoms and flu infection.
There is little transparency about the extent of infection occurring on US dairy farms
The more infections there are in dairy cows, the more likely it is to infect people who work with them, and the more opportunities there are for H5N1 to evolve into a virus that spreads efficiently to humans.
Despite this risk, most states rely on farmers to self-report infections in their herds. Means widespread distrust of government and public health across the agricultural industry Self-report is rareAnd the farm cannot be forced to check workers or animals Unless their state agency mandates it. “If these state public health agencies aren’t willing to do that, and state governors aren’t willing to say, ‘Hey, there’s an ongoing outbreak that’s causing a public health concern, we need to know what’s going on,’ we won’t have the information,” Lakdawala said.
Although bird flu has only been reported on poultry farms in Missouri and not dairy farms, that doesn’t mean it’s not there, Nuzzo said. This means farmers are not testing their workers or cows for the virus, or they are not reporting it.
We are not prepared for another pandemic
Many experts worry that Americans’ low trust in institutions will pose huge challenges in the event of another pandemic, especially an airborne virus. Lakdawala says that makes it especially important to do what is necessary to deal with this outbreak. This would mainly include established preventive measures on dairy farms and stockpiled vaccines for those at highest risk of infection.
Seasonal flu is coming
The seasonal flu virus is about to hit the United States in a few months.
When animals are co-infected with different flu viruses at the same time, they “mixture the ship“For viruses, allowing parts of their genomes to be exchanged. This can lead to new viruses that are easier to transmit, better at causing disease and, above all, novel for the human immune system.
This could get H5N1 close to jumping Lakdawala’s third hurdle. “We don’t want these two viruses to swap genes,” Nuzzo said.
what can you do
There are steps you can take to reduce your already low risk.
Get a seasonal flu shot
Every episode of bird flu infection in a human makes a good case for a seasonal flu shot, Nuzzo said, especially for those who work on poultry or dairy farms. Everyone who gets vaccinated against the seasonal flu is less likely to become a mixing vessel for some new nightmare Frankenflu.
Avoid raw milk
Raw milk contains a ton of H5N1 virus: In April, 14 percent of American raw milk Contains live virusAnd the number could be higher now that more farms have been affected. Drinking raw milk has never been safe, but it’s especially dangerous now; It’s much safer to stick with pasteurized dairy products, Nuzzo says
Avoid risky contact with farm animals
Fruits often bring farm festivals, and with them, plenty of contact opportunities with animals asymptomatically infected with H5N1, Lakdawala said. “Don’t get close to the animals,” Lakdawala says, and wash your hands often during and after farm visits. If you work on a dairy farm or in a veterinarian’s office, wear a face shield and other personal protective equipment (the Centers for Disease Control and Prevention (CDC) has some Helpful recommendations) to protect yourself from the splash.
Protect yourself from high-risk infections
Vadelia says: “There are only two settings people put in place when thinking about the risk of emerging infections: “Low risk and ‘Oh my God’. 19 and mpox are currently a greater threat to the general population than H5N1.
So if you’re someone who wants to avoid getting sick, Nuzzo recommends getting your Covid booster this fall, wearing a mask in busy places and congregating outside instead of cramming inside. If you would benefit from one mpox vaccineGet one.
For now, worrying about bird flu is mostly the job of government officials and farm owners. The best way forward for the general public is to control the variables you can, Nuzzo says. “Worrying is not a defensive move.”
