Wednesday, December 07, 2016

Japan : Wild Bird H5N6 Update


Excluding poultry, Japan - as of 1800 hrs (local time) today - has now recorded 41 HPAI positive wild birds across 9 Prefectures. Not all of these reports have been validated as being due to H5N6, but all that have been fully tested have turned out to be this recently arrived subtype. 
Japan's Ministry of Environment handles the non-farm detections of the virus (wild birds & environment), and their Information about the highly pathogenic avian influenza web page has been updated almost daily since H5N6 arrived in Japan in mid-November.
Since we last checked in on Friday (see Japan: H5N6 Spreading Rapidly Via Migratory Birds), the MOE has posted 13 new reports (see below).

So many, that it is getting difficult to keep track (Note: Not all of the above reports have been confirmed). 

Luckily, today the MOE also posted a summary chart, showing when and where 41 wild birds have tested positive for the HPAI.

As in Europe, where reports of H5N8 are coming in almost hourly, any listing is already outdated before it can be published. 

Exactly why H5N6 and H5N8 appear to be spreading faster, farther, and with more virulence than we've seen before is - as yet - a mystery, although a study (see EID Journal: HPAI A(H5Nx) Viruses With Altered H5 Receptor-Binding Specificity) recently suggested:
`Altered receptor-binding properties might affect the balance between HA and NA, enable the virus to acquire different NA subtypes, and might result in altered host range and spreading.'

Regardless of the cause, neither virus appears to be slowing down. Regions and countries that have not yet been visited need to be alert to the possibility they could be next.


jun-s said...

Here's new phylogenetic information from Japan's National Agriculture and Food Research Organization:

Michael Coston said...


Thanks for the link. Much appreciated.