A new pandemic

The revelation - just over a year ago - that goats and dairy cattle were susceptible to HPAI H5 infection wasn't the first such `Aha!' moment with unexpected influenza hosts.  A little over 20 years ago, most researchers believed cats and dogs weren't susceptible to influenza A viruses. 

In 2017 the CDC added Canine H3N2 to their IRAT List of zoonotic influenza viruses with pandemic potential, albeit with relatively low (3.7)

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Chinese scientists over the past decade have visibly increased their scrutiny of novel H3 viruses, as they are commonly observed in wild birds and poultry, and are increasingly spilling over into mammals (see EID Journal: Evolution of Avian Influenza Virus (H3) with Spillover into Humans, China).

All of which brings us to a new study from researchers at the Guangdong Provincial Pet Engineering Technology Research Center, which used serial passaging experiments (in murine lungs), to generate a more pathogenic and mammalian adapted virus. 

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In April of 2020,  China's MOA reclassified dogs as `companion animals' rather than `livestock', although it is estimated that somewhere between 10 and 20 million dogs are farmed/abducted in China each year for fur and/or meat. 

But even in countries where such practices uncommon, animal shelters have proven excellent venues for extended chains of infection (e.g. Canine parvovirus, feline panleukopenia, canine and feline viral respiratory pathogens, etc. )

The avian H7N2 outbreak in cats across several NYC animals shelters over Christmas of 2016 spread to hundreds of felines, and spilled over into several workers (see J Infect Dis: Serological Evidence Of H7N2 Infection Among Animal Shelter Workers, NYC 2016).

Admittedly, the emergence of a human-adapted H3N2 virus is probably a long-shot. But the more opportunities we give it, the greater the chances of it eventually getting lucky. 

And since it isn't just canine H3N2 - but rather a large (and growing) array of novel flu viruses all with varying degrees of zoonotic potential (e.g. H5N1, H5N5, H5N6, H9N2, H10Nx, etc.) -  the smart money is on preparing now for what could be a very bumpy road ahead.