|2017 HPAI Outbreaks - Credit IZSV|
Last week Italy's IZSV (Istituto Zooprofilattico Sperimentale delle Venezie) confirmed a pair of HPAI H5 outbreaks in Mantua Province, in northern Italy (see Italy Reports Two New Outbreaks Of H5N8), bringing their 2017 outbreak total to 19.
Over the past couple of days three more outbreaks have been confirmed (2 as HPAI H5, 1 as HPAI H5N8).
It is very likely these HPAI H5 outbreaks will be be confirmed as H5N8 in the days to come. A description of these latest outbreaks from the IZSV follows:
27/07/2017 – On 27 July, the National Reference Laboratory (NRL) for Avian Influenza and Newcastle Disease confirmed as positive for Avian Influenza A virus subtype H5 a fattening turkey farm in Verona province (Veneto region). At the moment of the epidemiological investigation, 12.200 turkeys (around 70 days-old) were present. The turkeys started to exhibit nervous symptoms last Sunday (23/07/2017), and the next day a slight increase in mortality was observed.
Still on 27 July, the Regional Laboratory of Lombardy and Emilia-Romagna confirmed as positive for Avian Influenza A virus subtype H5 a laying hens farm (about 120.000 birds) located in the province of Mantua (Lombardy region).
Further information on virus characterization and on the cases will be provided as soon as available.
Culling procedures for the positive fattening turkey farm in Verona (confirmed on the 25/07/2017) were concluded today, under the supervision of the Veterinary Services.Although this past winter's massive HPAI H5 epizootic has been over for most European countries for several months, during June and July we saw a small resurgence of outbreaks in poultry and wild birds cut a swath across Luxembourg, Belgium, and just barely into northern France (see Belgium Reports Another Outbreak of HPAI H5N8).
26/07/2017 – The virus detected in a fattening turkey farm in Verona province, confirmed yesterday (25/07/2017), has been characterised by the National Reference Laboratory as Highly Pathogenic Avian Influenza virus subtype H5N8.
25/07/2017 – On the evening of 24 July, an increase in mortality was reported in a fattening turkey farm in Verona province (Veneto region). On 25 July, the IZS delle Venezie confirmed the case as positive for Avian Influenza virus subtype H5. At the moment of the epidemiological investigation, 17.724 turkeys (112 days-old) were present. Starting on Sunday, a slight increase in mortality was observed in one of the five sheds at the farm. The farm is located in one of the most densely populated poultry areas in Italy.
The UK, Finland, and the Netherlands all reported single outbreaks, while during the same time period, Italy has reported six new outbreaks.This is a decided change over what was seen with the H5N8 virus during previous summers, when the virus all but disappeared (see PNAS: The Enigma Of Disappearing HPAI H5 In North American Migratory Waterfowl).
The virus acquired significant changes (see EID Journal: Reassorted HPAI H5N8 Clade 18.104.22.168. - Germany 2016) during the summer of 2016, and now appears to be more virulent in wild and migratory birds (see here), and has demonstrated an ability to infect a much wider range of birds (see here).These changes in behavior are a reminder that influenza viruses change constantly, and have a remarkable ability to adapt to new hosts, and new environments, over time. Simply put, what we think we know about any given flu virus today, might not hold true tomorrow.
Which is why we should expect surprises going forward.