Bird flu is a huge problem now – but we’re just one mutation away from it getting much worse

Avian flu is known as one of the most infectious diseases: the R number, which was often discussed for the spread of Covid-19, can be as high as 100 for avian flu, meaning one bird can infect as many as 100 others. And the past few months have seen exponential spread of the virus, with Britain and Europe hit especially hard.

 A Dolphin, a Porpoise and Two Men Got Bird Flu. That’s a Warning to the Rest of Us.

If these four events — one dead dolphin, one dead porpoise and two men testing positive for a dangerous bird virus — seem disconnected and insignificant, perhaps it’s because you haven’t heard of “viral chatter.”

 Bird flu: What is it and what's behind the outbreak?

The H5N1 strain is deadly and can spread through entire flocks of domestic birds within a matter of days, through birds' droppings and saliva, or through contaminated feed and water.

 Why is bird flu so bad right now?

The virus is running amok around the world. Possible explanations include an enhanced ability to replicate or infect more bird species.

Explainer: what is H7N9 bird flu?

Influenza A strains are classified according to the occurrence of different numbered types of haemagglutinin (H), a protein responsible for binding the virus to cells, and neuraminidase (N), enzymes that help the virus spread. The H proteins are numbered 1 to 17, and the N proteins are numbered 1 to 11. However, this doesn’t correspond with severity.

The Looming Threat of Avian Flu

Last year’s outbreak showed just how difficult it is to protect America’s agricultural system from devastating diseases. Next time it could be even worse.

An Engineered Doomsday

Scientists have long worried that an influenza virus that has ravaged poultry and wild birds in Asia might evolve to pose a threat to humans.

Avian Flu Symptoms: How Can You Tell If You Have H5N1?

The diagnosis of H5N1 based on symptoms alone is difficult because they are so similar to other flu strains; laboratory testing is required to confirm infection, according to the the US Centers for Disease Control and Prevention (CDC) The bird flu is generally spread to people through direct contact with infected birds or poultry livestock.

Bird flu is back: here's what you need to know

Like humans, birds — from chickens to ducks and other wild poultry— get sick with the flu sometimes. When they do, bird flu virus can spread easily among them by way of respiratory secretions and feces, reaching epidemic proportions very quickly. The reason experts worry so much about bird flu, however, is because it's an easily transmissible respiratory virus and some strains have managed to infect humans — with deadly outcomes.

Bird Flu Is Spreading in Asia, Experts (Quietly) Warn

Many microbiologists consider influenza to be the virus most likely to start a pandemic that kills millions, as the 1918 Spanish flu did. But the flu is notoriously unpredictable. Public health experts have become wary about raising alarms over new strains because the grave predictions made in 2005 and 2009 turned out to be overblown.

Changes to Bird Flu Virus May Make Human Transmission More Likely

Flu viruses attach to receptors found on the cells of their intended victims. Bird flu viruses attach to one type of receptor. The cells found in the human upper respiratory tract — where a flu infection takes hold — are mostly lined with a different type of receptor, which explains why these viruses don’t easily infect people. The Scripps team, however, found that by tweaking the genetic code of H7N9’s hemagglutinin gene, they could change the receptors the virus latched on to, from the bird type to the human version.

China’s appetite for fresh chicken is making its bird flu epidemic worse

H7N9, or avian influenza A, is a virus that infects both human and birds and manifests with flu-like symptoms. Most of the cases of human infections were linked to recent exposure to live poultry or contaminated environments like livestock markets.

Proliferation of Bird Flu Outbreaks Raises Risk of Human Pandemic

While avian flu has been a prominent public health issue since the 1990s, ongoing outbreaks have never been so widely spread around the world - something infectious disease experts put down to greater resilience of strains currently circulating, rather than improved detection or reporting. While there would normally be around two or three bird flu strains recorded in birds at any one time, now there are at least half a dozen, including H5N1, H5N2, H5N8 and H7N8.

The New Bird Flu: How Dangerous Is Avian Flu H7N9?

The virulence of the H7N9 virus is not the only reason health officials around the world are scurrying to figure out the scope of the danger it poses. Genetic evaluation of the H7N9 virus shows it has the ability to mutate readily.

This Year’s Bird Flu Outbreak Killed a Record 281 People In China

This year's outbreak is more deadly than every other year combined.

What Happened to Avian Flu?

It never really went away. We just forgot about it.

Where Is Avian Flu Hiding?

The H5 flu strains may not be spreading because of conditions on the farms themselves. Instead, wild ducks and geese appear to be harboring the virus. The birds have been natural reservoirs for other H5 viruses without getting sick, making them likely couriers of the current strains gripping the nation.

Will the World's Most Worrying Flu Virus Go Pandemic?

Influenza viruses come in many flavors—H5N1, H1N1, H3N2, and so on. The H and N refer to two proteins on their surface, and the numbers refer to the versions of those proteins that a particular virus carries. H1N1 was responsible for both the catastrophic pandemic of 1918 that killed millions of people, and the most recent (and much milder) one from 2009. H5N1 is the bird-flu subtype that has been worrying scientists for almost two decades. But H7N9? Until recently, it had flown under the radar.

What is bird flu and are we at risk? WIRED debunks the myths

H7N9 and H5N8 strains of bird flu are making a resurgence - what does the virus mean for humans?

High Containment

Lab that created risky Avian Flu had “unacceptable” biosafety protocols.

One way to fight off bird flu: extra-CRISPRed chicken

You might not think you have much in common with the chicken on your plate, but we’re not so very different from our feathered friends. The biggest similarity that concerns epidemiologists is a shared susceptibility to the so-called avian flu (the strain H1N5). Although epidemiologists and governments around the world are trying to prepare for future pandemics of this disease, geneticists have a potential loop-hole: creating chickens that can’t get the flu at all. Although much recent coverage of CRISPR has been focused on gene-edited humans, figuring out how to alter the animals we eat is a burgeoning field.

Can Gene Editing Stop The Bird Flu? Here Is The Latest With Chickens

They probably won't be wearing capes and tights. But will creating new "superchickens" help prevent the next human influenza pandemic? If so, chicken science may have just crossed a road in moving towards genetically engineering chickens to be resistant to the bird flu.

What happened to bird flu? How a major threat to human health faded from view

“It is good news, the fact that overall the H5N1 problems have reduced,” he said. “But you know, you can look at it the other way around. So now we have two high pathogenic [H5] viruses kicking around.”

Why Chinese Scientists Are More Worried Than Ever About Bird Flu

"Ten years ago, H7N9 was less lethal," says Guan. "Now it's become deadlier in chickens. Before it barely affected chickens. Now many are dying. Our research shows it can kill all the chickens in our lab within 24 hours. If this latest mutation isn't stopped, more will die." Guan says this is very bad news for a global poultry industry that's worth hundreds of billions of dollars, and he says China's government is already looking into vaccinating chickens.