Bird Flu Is Making Headlines Once Again: What’s The Current Situation?

After a relatively quiet summer, bird flu is beginning to rear its ugly head once more. But even if we haven’t been talking about it as much, that doesn’t mean the virus has gone away – and it’s not only the highly pathogenic H5N1 strain that’s been making moves. 

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H5N1 outbreaks on US farms

A strain of H5N1 highly pathogenic avian influenza (HPAI) has been causing a massive headache for farmers in multiple states for a few years now. As well as impacting poultry farming and the price of eggs, the virus has proven itself to be adept at infecting multiple mammalian species, meaning cattle farms have also been severely affected. 

There have also been 70 reported human cases per the latest data from the Centers for Disease Control and Prevention (CDC). Thankfully, most have been mild, though one patient in Louisiana did die from the virus in January 2025. Concerningly, one study also found evidence of silent spread, after three vets were found to be harboring antibodies despite having had no symptoms. 

Things have seemed to calm down a bit over the last few months. In June, Secretary of Agriculture Brooke L. Rollins announced that wholesale egg prices had dropped 64 percent, suggesting that the current administration’s biosecurity plan “has worked” – however, Rollins also presciently warned of a “potentially challenging fall” to come. 

The latest data from the US Department of Agriculture, correct as of October 23, reveals that almost 6.5 million birds have been affected by HPAI in the last 30 days, prompting the New York Times to declare that “bird flu is back”. That includes outbreaks in 32 commercial and 29 backyard flocks.

Minnesota is currently seeing the greatest number of outbreaks, but a single outbreak in Washington state affected almost 2 million birds. There has also been one confirmed cattle outbreak in the last 30 days, in Idaho. 

One of the concerns being raised as we head into this winter season is a lack of federal communication and potential disruptions to surveillance resulting from the ongoing shutdown. “Because of the government shutdown, I know less than I would normally know,” Dr Amy Swinford, director of the Texas A&M Veterinary Medical Diagnostic Laboratory, told the New York Times.

In the run-up to Thanksgiving and Christmas, it’s a particularly concerning time for turkey farmers.

“Winter” and “flu” go hand-in-hand, but usually we’re talking about the seasonal flu epidemics that affect the human population. While H5N1 HPAI doesn’t quite seem to follow this same seasonal pattern, and there’s currently no evidence of transmission between people, there’s a known link between lower temperatures and flu virus spread.

Some recent studies have suggested that seasonal flu vaccines could offer some protection against H5N1. One group found that the parts of the virus that are targeted by the T cell response in humans are largely conserved in H5N1, suggesting that pre-existing immunity could “blunt the severity of human H5N1 infections”.

On the other hand, another recent study suggested that the latest seasonal vaccines are unlikely to be enough to protect the most vulnerable, should H5N1 become more widespread in humans.

Still, now is the ideal time to get your flu shot if you haven’t already.

H5N1 in Europe

It’s not only the US that is being impacted by H5N1 right now, with outbreaks being reported in a number of European countries.

HPAI was detected on a large commercial farm near Penrith in the northwest of England last week, prompting the installation of a 3-kilometer (1.9-mile) protection zone and the reported culling of over 10,000 birds.

Meanwhile, German scientists have been sounding the alarm over a “real disaster”, as over 1,000 migratory cranes have been found dead at a major resting site for the species. “We have been working with many volunteers in managing this bird migration gathering place for 25 years and have never experienced anything like this,” said biologist Norbert Schneeweiss in a Global News video.

Wild birds can be both vectors of and victims to avian flu. Waterfowl are particularly good spreaders of infection, as we discussed with vaccinologist Dr Florian Krammer in a recent episode of our podcast The Big Questions.

Concerns about migratory animals and birds also recently prompted France to raise its bird flu alert to the highest level. A wildlife park in Cork, Ireland, also just reported a number of cases in its greylag goose population, prompting closure of the park; the virus is thought to have been introduced by neighboring wild birds.

H5N1 and H9N2 human infections in Asia

As reported by the University of Minnesota’s Center for Infectious Disease Research and Policy (CIDRAP), Cambodia recently announced a case of H5N1 in a 3-year-old girl, who is said to be undergoing treatment in intensive care. Domestic ducks and chickens in the girl’s home and neighboring houses were said to have been sick and dying for around a week before she became infected.

According to a recent report from the Hong Kong Center for Health Protection (CHP), a second patient in Cambodia has now been hospitalized with the virus, marking the 17th case this year. The patient is a 14-year-old girl from Takeo Province.

The report also discusses four retrospectively reported human cases of a different avian flu strain, H9N2, in mainland China. All of the individuals mentioned came down with the infection in February 2025. CIDRAP reports that there have so far been 25 cases of H9N2 in China in 2025, following 11 cases in 2024.

This demonstrates that avian flu goes way beyond H5N1, and this is not the only subtype we need to be wary of. There are 18 known types of hemagglutinin (the “H” number) and 11 types of neuraminidase (the “N” number), and more than 130 different combinations have been identified, most of them in birds.

History shows us how flu viruses can spill over from animal reservoirs into the human population and cause pandemics. “Since there are so many subtypes out there,” Krammer told IFLScience, “any subtype could do that.” And that’s why it’s so vital that scientists keep a close eye on flu – and we do mean all flu – all the time.