Tuesday, July 12, 2016

DEFRA: Preliminary Assessment Of Ontario's LPAI H5 Outbreak


The UK's DEFRA (Department for Environment, Food & Rural Affairs) continues to provide some of the best follow up and analysis of bird flu outbreaks, both in Europe and in Canada.

Today they've released a preliminary report that tags Ontario's recent LPAI H5 discovery as a mild North American strain, not part of the Asian H5 lineage that arrived in Canada in the fall of 2014. 

I've included some pertinent excerpts, but the full assessment can be downloaded from the link below.

Preliminary Outbreak Assessment
Outbreak of H5N2 LPAI in ducks in Canada

11 th July 2016
Ref: VITT/1200 H5N2 LPAI in Canada

Disease Report

Canada has reported an outbreak of H5N2 low pathogenic avian influenza (LPAI) in Ontario in ducks (see map; CFIA, 2016). The holding contained 14,000 birds of 10-12 weeks old in a single barn. No clinical signs increased mortality was observed; the birds were sample for routine pre-export testing (OIE, 2016). Disease control measures  have been implemented including, stamping out and a surveillance zone. There were three outbreaks of H5N2 HPAI Southern Ontario in April 2015. Canada has been considered free of Avian Notifiable Disease since October 2015.

Situation Assessment

There was a large avian influenza epizootic in North America in 2014-2015, with four separate strains of HPAI viruses circulating (H5N1, H5N2, H5N6 and H5N8) and by the end of 2015, 211 outbreaks in commercial premises, 21 in backyard premises in the USA and just 2 backyard and 15 commercial premises in Canada, of which three were in 

Ontario, had all tested positive for one or other HPAI viruses. Sequence analysis suggested these viruses had arisen as a consequence of recombination events between local LPAI viruses and Eurasian origin H5N8 HPAI viruses of Clade which circulated in migratory wild birds across Europe, Asia and America; hence the nomenclature of Eurasian / North American H5Nx HPAI (USDA, 2015a).

This EA/NA H5N2 HPAI virus was responsible for the previous outbreaks in Southern Ontario, but according to the disease report, this latest outbreak is a LPAI virus with H5 sequence closely related to the North American wild bird origin H5 LPAI viruses, suggesting this outbreak may simply be incursion from local wild waterfowl or indirect transmission via contaminated equipment, water, feed, bedding etc of the North American LPAI strain. 



There is no significant increase in risk for disease incursion into the UK as a result of this outbreak. We consider there to be an all-year-round, albeit variable, low risk of incursion of any notifiable avian disease into poultry throughout the year through contact with wild birds or contaminated environment and the heightened but low level reflects the imminent start of the migration season.

We will continue to monitor the situation closely. We would like to remind all poultry keepers to maintain high standards of biosecurity, remain vigilant and report any suspect clinical signs promptly and in addition using the testing to exclude scheme for avian notifiable disease where appropriate for early safeguard. For more information, please see www.defra.gov.uk/ahvla-en/disease-control/nad

The risk level for the UK remains at low, but heightened.

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