Thursday, June 22, 2017

OIE: South Africa Reports Outbreak Of HPAI H5N8


Just over 3 weeks ago HPAI H5N8 was confirmed in the DRC, and a week ago we learned it had spread to at least 14 locations.  A few days after the DRC's first report, the virus turned up at a large poultry facility in Zimbabwe - 1400 miles to the south - and only a few hundred miles from the South African border.
Since then, we've been waiting - along with officials in South Africa - to see whether virus would make it into poultry-rich South Africa.
Just shy of two weeks ago, in DAFF: South Africa On Alert For HPAI H5N8, we looked at the precautions the South African government ordered in an attempt to prevent the virus's entry.  Today, via the following OIE report, we now learn that a large poultry holding in Mpumalanga has tested positive for this well-traveled virus.

The concern, beyond the potential impact on a South Africa's poultry industry, is that this recently reassorted HPAI H5N8 virus continues to spread faster, and farther, than any HPAI virus we've seen to date.

Since it emerged as a threat in South Korea in 2014, it visited North America and Europe during the winter of 2014-15 - and after laying low for a year - this past winter it invaded Europe, the Middle East, West Africa, and now Southern Africa.
This recently emerged H5N8 virus seems particularly well adapted for carriage by wild and migratory birds, and has spawned a number of reassortants (H5N2, H5N5, H5N9) during its travels.
This is the first serious intrusion of HPAI H5 into the southern hemisphere, and given the migratory pathways between the Northern and Southern Hemisphere - particularly those linking Africa to Europe and Asia - could change the dynamic of HPAI H5's spread and future evolution. 

Last winter, the FLI: Updated Risk Assessment On HPAI H5 warned specifically that:

`Generation of reassortants always must be expected when different high and low pathogenic influenza viruses are circulating in one population.'

Relevant because, whatever happens with this promiscuous virus in the Southern Hemisphere, may not stay in the Southern Hemisphere.

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