Last Friday, in OIE Notification: HPAI H5N6 In Greece, we learned that an avian flu outbreak originally identified last month as H5N8 was, in fact, HPAI H5N6 - making it the first detection of this particular subtype in Europe.
Unknown on Friday, however, was the lineage of this particular virus. A question I addressed in Friday's blog:
What isn't clear from this report is whether this is a local reassortment - such as we've seen previously from H5N8 (generating H5N5 in Europe & H5N2 in North America) - or if this is the first arrival of the Asian H5N6 virus, which has been spreading across China, South Korea, Japan, and Vietnam.
Last night, Lisa Schnirring - writing for CIDRAP News - shed some light on this question, in a report called:
Since the emergence of H5N5 (a reassorted spin-off of H5N8) in Europe late last year we've been told to expect additional reassortments. The FLI: Updated Risk Assessment On HPAI H5 has warned repeatedly that:
`Generation of reassortants always must be expected when different high and low pathogenic influenza viruses are circulating in one population.'
While this particular outbreak of H5N6 appears to be a local reassortment, there is little to suggest that the Asian H5N6 (or any other avian subtype currently circulating in Asia), couldn't hitch a ride on migratory birds and begin to spread globally as we have seen already with H5N1 and H5N8.
A scenario the FAO warned about more than two years ago - before H5N8 made its big move into Europe and North America -in FAO-EMPRES Report On The Emergence And Threat Of H5N6.
For reasons that are less than clear, HPAI carriage by migratory birds appears to be on the ascendant these past few months, making the surveillance and study of how they are spreading and evolving of utmost importance.