The news that a Texan had been infected with H5N1 bird flu on Monday added a worrying aspect to a global outbreak that is inching closer to humans.
The patient was a dairy farmer and contracted the virus from an infected cow, making him the second American to be infected after a person in Colorado in 2022.
While there is no sign of human-to-human spread (a development that would signal the start of a human epidemic), experts say the ease with which the strain jumps between species increases the risk that it will evolve to infect us more easily.
This H5N1 variant has been detected in nearly every corner of the world, from arid Antarctica to the deep ocean, since it emerged in 2020. But it’s developments a little closer to home that are causing concern.
He’s been on US poultry farms for years, goats and now cows (not to mention a pet dog in Canada). DailyMail.com spoke to seven infectious disease experts and virologists who have been following the H5N1 bird flu for years about what the development in Texas means.
Testing revealed that an unknown number of cows tested positive for H5N1 Avian Influenza A in Texas, Kansas and New Mexico. Iowa is currently “monitoring the situation” as it is also a large dairy producing state. It comes after a goat in Minnesota tested positive last week. Avian flu has also been found in foxes, lynx, striped skunks, raccoons and coyotes since the 2022 outbreak.
Dr. Leonard Mermel, an infectious disease expert in Rhode Island, warned that repeated infections in mammals increased the risk of the virus acquiring harmful mutations. Dr. Diego Diel of Cornell University warned that the cases highlighted the ability of bird flu to spread to mammals.
Dr. Aaron Glatt, an infectious disease expert at Mount Sinai, New York, warned: “It is absolutely true that H5N1 has the potential to cause a pandemic.
‘People who work with these animals must be careful.
“The more this virus spreads, the more likely it is to become a strain that can mutate and begin to spread from person to person.”
The H5N1 that is spreading around the world emerged in 2020 after a bird became infected with both a bird flu from domestic birds and a virus from wild birds.
During infection, the two viruses met in the same cell and exchanged genes (in a process scientifically called recombination) to create the new virus that now had multiple attributes that made it better at infecting bird cells.
It spread rapidly around the world with the first cases being identified in Europe, before infections were also detected in Africa, the Middle East and Asia.
Experts fear infections in cattle and other mammals could increase the risk of the virus adapting to spread in humans (file image)
Dr. Leonard Mermel, an infectious disease expert at Brown University in Rhode Island, said the fact that the disease was spreading among mammals “increased the risk” that the virus would evolve to infect humans.
“Viruses have multiple mutations in each replication cycle (each time they make copies of themselves),” he said.
‘Every time that process occurs, where viruses replicate, there can be many, many mutated viruses that leave one (infected) cell to infect other cells.
“By chance, one could have a mutation that allows it to bind to these mammalian cells, which would then allow it to be transmitted from mammal to mammal (and potentially from human to human).”
While jumping between species carries the risk of a rare mutation, experts are particularly worried about the virus reaching one population: pigs.
Pigs have receptors on their lung cells very similar to those of humans and can harbor human and bird viruses simultaneously.
Infections in pigs would be a warning sign that the virus could be enhancing its spread to humans.
There is also the risk of a pig becoming infected with a human and bird flu virus at the same time, which could swap genes to create a new and potentially more dangerous virus.
In 2009, a swine flu outbreak occurred when a pig was infected with a human and avian flu virus simultaneously. This allowed the avian virus to use the human virus model to begin spreading between humans.
The outbreak caused 60 million swine flu infections in humans in the United States alone, nearly 300,000 hospitalizations and about 12,400 deaths.
John Fulton, a pharmaceutical industry expert working on a bird flu vaccine, told DailyMail.com: “I think we’re past the ‘if’ and we’re on our way to when…” when asked if this H5N1 strain would cause an outbreak in humans. .
He has been working for years to develop a vaccine against bird flu, because the seasonal vaccines used to protect against human flu do not offer protection.
He is now about 18 months away from creating a new vaccine for poultry.
Even experts who aren’t too worried about the Texas case believe it could be a symbol of the virus starting to become more dangerous to humans.
Dr Michael Osterholm, who has been following bird flu for decades, said: “These cases are cause for concern and we will be sure to follow what happens with them.”
“There is no doubt that we will have bird flu pandemics.”
Adding caution, he said: “But we are not seeing any cases in pigs and pigs are the real bridge species for us because they have the same receptor sites in the lungs.”
Dr. Bill Schaffner, an infectious disease expert at Vanderbilt University in Tennessee, said: “(Cases of bird flu) occur periodically among humans, but it is rarely transmitted from person to person.”
“The genetic part of the virus that would allow it to be easily transmitted from person to person is still missing.”