Study finds clues to avian flu resistance
The study examined why some species of birds are more susceptible to avian flu than others.
A new study has identified several candidate genes which may explain why some species of birds are less susceptible to highly pathogenic avian influenza than others.
A collaboration between researchers from the Roslin Institute, Edinburgh, and the National Institute of High Security Animal Diseases, Bhopal, the study sought to determine why some species are better at resisting the disease than others.
The researchers looked at how six species of birds responded to infection with low pathogenic avian influenza (H9N2) and two strains of highly pathogenic avian influenza (H5N1 clade 2.2 and clade 2.3.2.1). The species investigated were chickens and turkeys (which are highly susceptible to the virus), ducks and crows (which tolerate and spread the virus), and geese and pigeons (which are highly resistant to it).
After infection, tissue samples were collected from the brain, ileum and lung of the birds at three different intervals. Transcriptomic responses were recorded and compared.
The results showed that susceptible birds had higher viral loads in the brain, while resistant birds had stronger differential regulation of genes associated with nerve function in the ileum and lung. Candidate genes which might help with resistance were identified and differences in how quickly the immune systems of ducks and crows respond to different strains of the virus were also discovered.
The findings of the study could pave the way for further investigations into the candidate genes. In future, these genes could be targets for selective breed or gene editing to improve the resistance of domestic birds to avian flu.
Since 1 October 2022, there have been 174 confirmed cases of the H5N1 strain across the UK.
Dr Katrina Morris, lead author of the study, said: “Understanding the biological processes triggered by avian flu, and the factors that influence resistance, is important in the effort to limit the risk of bird flu in commercial poultry.
“Our findings show that early interaction involving the immune system is key; they also highlight the importance of interplay between the birds’ nervous and immune systems in response to infectious disease, and flag several genes that may be influential in how infection plays out.”
The study was published in Frontiers in Cellular and Infection Microbiology.
The Animal and Plant Health Agency (APHA) has updated its online reporting service for dead wild birds.
