Yesterday, in HPAI Reported At Hungarian Duck Farm, I blogged about a preliminary report of what appeared to be HPAI H5 on a duck farm in Füzesgyarmati (see map above), in the southeastern part of Hungary (see map above). Today we have confirmation via the following OIE report.
On 23 February 2015, a suspicion of avian influenza was reported to the National Food Chain Safety Office. The local authority immediately visited the affected holding, which is located in Füzesgyarmat, in Békés County. 22,000 fattening ducks are kept in the holding. Neurological signs, nasal discharge and increased mortality were observed. Official samples were taken on the same day. On 24 February, the National Reference Laboratory confirmed avian influenza H5N8 strain. In the neighborhood of the affected holding, there are three contact holdings. All the birds kept in the affected and in the contact holdings will be killed and destroyed.
On 24 February, the National Reference Laboratory confirmed avian influenza virus H5N8 by RT-PCR and, on the next day, by sequencing partial HA and NA sequence fragments. The amino acid sequence at the hemagglutinin cleavage site is consistent with highly pathogenic avian influenza (HPAI). Preliminary results suggest that the sequences are very closely related to the Asian and also to the four European H5N8 HPAI virus sequences reported so far. Whole genome sequencing is in progress.
- Control of wildlife reservoirs
- Stamping out
- Movement control inside the country
- Disinfection of infected premises/establishment(s)
- Vaccination prohibited
- No treatment of affected animals
Of the Highly Pathogenic Avian Influenza (HPAI) viruses that have emerged to date, H5N8 seems particularly well suited for long-distance traveling, having spread from Northeastern Asia to Europe, Japan, Taiwan, the Pacific Northwest, and into at least six western states in the US in less than a year.
Hungary lies within the NE/SW oriented Black Sea / Mediterranean Flyway, which runs from northern Russia to western and central Africa. This flyway crosses south central Europe where H5N8 has recently been reported (Bulgaria & Italy), and across the Middle East and down to Nigeria – both regions having a history of H5N1.
Hungary’s location in the Flyway
You’ll notice that while these migratory bird flyways run essentially north to south – they overlap – which can allow for the lateral (east-west) movement of avian viruses over time as well. Viruses that are endemic in the East Asia Australian Flyway could conceivably seep into the Central Asian Flyway, and from there move further west into the East African or Black Sea flyways.
We’ve looked at the role of migratory and wild birds in spreading influenza viruses many times, including several weeks ago in Erasmus Study On Role Of Migratory Birds In Spread Of Avian Flu, and last fall in FAO Warns On H5N8’s Spread.
Although highly pathogenic in poultry, H5N8 has never been known to infect or cause illness in humans. But as this virus is related to several H5 avian viruses (H5N1, H5N6) that are known infect humans, the CDC maintains a cautious attitude (see CDC Interim Guidance For Testing For Novel Flu).