A bird flu virus that has spread to canines may hop hosts in the future, potentially infecting humans through their pet dogs, according to scientists at China Agricultural University.
Ever since the COVID-19 pandemic gained steam in 2020, more Americans have turned their eyes to the pathology and the origin of viruses, as well as methods to fight infection through vaccines and prevention. Although no dog-to-human infection of the H3N2 avian flu have been detected, the virus is evolving to exhibit new properties that show its potential of infecting other mammals in the future, such as humans.
The scientists published their study in the science journal eLife on April 11. The findings revealed that the virus infecting dogs is descended from H3N2, a type of avian flu. The virus first began affecting dogs nearly 20 years ago in China. It spread to American dogs by 2015. The virus causes mild respiratory symptoms in dogs, such as sneezing, coughing and lethargy. The mortality rate is low, according to VCA Animal Hospitals.
There was no proof of the virus spreading to humans from dogs, but experts believe the virus could mutate further if it continues to become established in dogs. The Independent reported that British scientists interpreted the study as revealing that dogs could be “patient zero” for the virus’s evolution. According to Professor James Wood, who heads the Department of Veterinary Medicine at the University of Cambridge, H3N2 seems to have become a dog-specific virus.
“The changes in the canine virus apparently are making it better adapted to transmit within mammals, as you might expect after such a long period in dogs,” Wood said in the article.
China Agricultural University’s research shows the virus could continue to evolve, making other mammals suitable hosts.
By studying tracheal cells from sick dogs ranging from 2012 to 2019, scientists learned that the H3N2 canine influenza virus has evolved to gain new phenotypic properties over the last 11 years. The phenotypic properties show the virus is improving its adaptation to mammals over a period of several years. Scientists also studied how the viruses react when infecting human cells.
If the virus continues to evolve, pet dogs may become the host from which the virus leaps to humans. Despite the lack of evidence that the virus impacts humans from their pet dogs, the research could give scientists a head start with potential cures or prevention methods to manage the virus.
However, a spokesperson for the CDC told Newsweek that the risk of infection from dogs to humans is low.
“In general, canine influenza viruses are thought to pose a low threat to people. To date, there is no evidence of spread of canine influenza viruses from dogs to people and there has not been a single reported case of human infection with a canine influenza virus in the U.S. or worldwide,” the spokesperson said.