Over the summer Russia has reported roughly 80 outbreaks of avian flu across much of their western region (see Russia's Summer Of Bird Flu Continues Into Fall) - but the exact subtype has been omitted in most reports - listed only as `HPAI H5'.
HPAI H5N8 has been the most commonly reported avian virus in Russia in recent years, but a newly reassorted HPAI H5N2 virus has also been reported a couple of times since last December (see Russia Notifies OIE Of A Second HPAI H5N2 Outbreak In Kostroma Oblast).With this fall's bird migration already underway in parts of the Northern Hemisphere - and with many birds overflying Western Russia on their way to Europe - the identity of the HPAI H5 viruses circulating in that region are of considerable interest.
We've the first detailed report from Russia's Rosselkhoznador (Federal Service for Veterinary and Phytosanitary Surveillance) on the recent outbreaks at a large poultry producer in Rostov, which identifies the virus as HPAI H5N8 clade 188.8.131.52. - and describes it as being `phylogenetically close' to the 2016/17 strains that caused Europe's worst epizootic.
On the study of the FGBU "ARRIAH" virus highly pathogenic avian influenza that caused the outbreak of the disease on the territory of the agricultural holding in the Rostov region
October 10, 2018
© Central Office
The reference laboratory of viral diseases of birds of the Federal Center for Animal Health (FSBI VNIIZZH) under the Rosselkhoznadzor at the end of September and beginning of October 2018 received samples of pathological material from chickens belonging to the White Bird – Rostov LLC (Rostov Region), for laboratory confirmation of the diagnosis of "bird flu".
As a result of studies conducted by the method of RT-PCR and nucleotide sequencing, the genetic material of influenza A virus was detected in samples of pathological material and the subtype H5N8 was identified. Thus, the reference laboratory of viral diseases of birds confirms the positive results obtained by the Rostov, Belgorod and Krasnodar regional and interregional veterinary laboratories on avian influenza in the study of pathological material from birds (White Bird - Rostov LLC).
When conducting a comparative genetic analysis of the obtained nucleotide sequences of fragments of the H and N genes, it was established that the identified virus belongs to the Asian genetic line, which has become epizootic in 2016–2018. in countries of Asia, Europe, the Middle East and Africa of the highly pathogenic avian influenza virus subtype H5N8 (clade 184.108.40.206).
It has been established that, according to these genes, the A viruses of the H5N8 subtype of birds, identified in 2016–2017, turned out to be the most phylogenetically close. in a number of regions of the Russian Federation (Krasnodar Territory, Voronezh Region, Rostov Region, Astrakhan Region, Moscow Region, Kaliningrad Region, Samara Region, Chechen Republic, Republic of Tatarstan, Republic of Mari El, Republic of Tyva, Republic of Kalmykia, etc .). The hemagglutinin cleavage site has the structure REKRRKRGLF, which makes it possible to characterize the virus as potentially highly virulent.
FGBU "ARRIAH" draws the attention of the veterinary services of the constituent entities of the Russian Federation, poultry farms and owners of poultry to the existing threat of the introduction and spread of highly pathogenic avian influenza and calls for strict observance of veterinary and sanitary measures for the maintenance and breeding of birds.
In the event of the detection of sick or dead wild and domestic birds, it is necessary to immediately inform the state veterinary service.
The reference laboratory of viral diseases of birds of the FGBU "ARRIAH" conducts molecular genetic and virological studies on the identification of identified influenza viruses and the study of their biological properties, and also continues to study samples of biomaterial from poultry farms and settlements.
While Europe saw a relatively mild bird flu season last winter - dominated by a recently arrived milder HPAI H5N6 (reassortment) - the existence of active pockets of HPAI H5N8 in Russia (and in parts of Eastern Europe) provide a potential conduit by which it could revisit Europe.
The good news is this latest report did not find HPAI H5N2, which less is known about (see DEFRA SitRep On HPAI H5N2 In Western Russia).We never know what to expect when the migratory birds return from their high latitude summer roosting spots, but we know that the greatest danger of seeing the spread of HPAI viruses each year is during the fall and winter months (see MAFRA Warns: South Korea's Fall Migratory Bird Season Begins).
Which means that for the next six months or so, biosecurity for poultry in the Northern Hemisphere needs to be at its highest.