Watching out for animal flu viruses that could trigger human pandemics

With the lifting of border restrictions and quarantine regulations, Australians can anticipate the reintroduction of influenza, affording a unique opportunity to learn important lessons about the epidemiology of influenza epidemics and pandemics, say the authors of an editorial published today by theMedical Journal of Australia.

Professor Kanta Subbarao, Director of the World Health Organization's Collaborating Centre for Reference and Research on Influenza at the Doherty Institute in Melbourne, wrote that improving collaboration between animal and human public health sectors was crucial to detecting and protecting against influenza in 2022.

"While our primary focus is onseasonal influenza, we must also remain vigilant about zoonotic and pandemicinfluenza viruses," she wrote.

"Although seasonal influenza viruses were in abeyance in 2020–2021, there was widespread influenza virus activity inanimalsglobally and within our own region.

"Highly pathogenic avian influenza A(H7N7) and low pathogenicity avian influenza A(H7N6) and A(H5N2) viruses were reported in Victoria, and swine influenza viruses have been detected in several states.

"The reason for public health concern is that novel (eg, animal) influenza viruses to which the human population lacks immunity could spread to cause a global pandemic if they cross the species barrier to cause human infections and spread efficiently from person to person.

"Does that sound familiar? We have learnt from COVID-19 that we ignore the animal–human interface at our own peril."

Professor Subbarao recommended four actions:

• We must establish surveillance at the animal–human interface because focusing on viruses that can cross thespecies barrieris an excellent place to start.
• We must invest in subtyping more influenza A viruses than we do (Box, B) because being unable to subtype as H1 or H3 may be the only indication that an animal virus has infected a human.
• We must improve communications between animal and human public health sectors so that we can institute active surveillance in people involved in culling large numbers of infected animals.
• We must work in public–private partnerships to lower the barriers to surveillance at the animal–human interface.

"Such efforts will be beneficial beyondinfluenza: the COVID-19 pandemic and recent reports of a new genotype of Hendravirusin Australian flying foxes are excellent reminders that other animal viruses that can cross species barriers bear watching," she concluded.