Researchers in the United States have confirmed avian flu is now being passed from mammal to mammal, raising concerns about the virus’s impact on humans.
A new study has provided evidence that a spillover of avian influenza from birds to dairy cattle across several U.S. states has now led to mammal-to-mammal transmission between cows and from cows to cats and a raccoon.
Associate Professor of Virology at the Department of Population Medicine and Diagnostic Sciences Diego Diel said this was one of the first times they had seen “efficient and sustained mammalian-to-mammalian transmission of the highly pathogenic avian influenza H5N1”.
Dr Diel said genome sequencing of the virus had not revealed any mutations that would lead to enhanced transmissibility in humans, but there was a concern the virus may adapt in mammals.
“The concern is that potential mutations could arise and spillover into humans (with) potentially efficient transmission in humans in the future,” Dr Diel said.
He said it was critical to continue to monitor the virus in affected animals and also in any potentially infected people.
“Early testing, enhanced biosecurity and quarantines in the event of positive results, would be necessary to contain any further spread of the virus.”
Dr Diel said infections from H5N1 were first detected in January, 2022, and have resulted in the deaths of more than 100 million domestic birds and thousands of wild birds in the United States.
