Alexander G. Durymanov

Influenza A(H5N8) virus isolation in Russia, 2014

In this study, we report the isolation of influenza A(H5N8) virus from a Eurasian wigeon (Anas penelope) in Sakha Republic of the Russian Far East. The strain A/wigeon/Sakha/1/2014 (H5N8) has been shown to be pathogenic for mammals. It is similar to the strains that caused outbreaks in wild birds and poultry in Southeast Asia and Europe in 2014.

Influenza A/H1N1pdm virus in Russian Asia in 2009–2010

In total 3566 blood sera samples were collected in the Russian Far East and Central and Western Siberia in 2009-2010. The presence of antibodies to influenza A/H1N1pdm, seasonal H1N1 and H3N2 influenza viruses in the sera was tested in the hemagglutination inhibition test. 29.5% of samples from the Far East were positive to pandemic influenza, this value for Central and Western Siberia is 2-fold lower (12.8% and 11%, respectively). Fifty-six influenza A/H1N1pdm viruses were isolated during 2009-2010 from samples collected in Central and Western Siberia and the Russian Far East. Molecular and genetic properties of 23 strains were studied. Nucleotide and amino-acid sequences of pandemic influenza virus strains were identical (99% identity or more) to reference strain A/California/04/2009. Sporadic substitutions in antigenic sites were detected but did not change antigenic characteristics of strains.

Genetic and biological characterization of avian influenza H5N1 viruses isolated from wild birds and poultry in Western Siberia

Three viruses included in the study were isolated from dead birds (A/duck/Omsk/1822/2006, A/chicken/Reshoty/02/2006, and A/duck/Tuva/01/2006), whereas the virus A/common gull/Chany/P/2006 was isolated from an apparently healthy gull during outbreaks of highly pathogenic avian influenza in Russia in 2006. The intravenous pathogenicity index (IVPI) of viruses A/duck/Omsk/1822/2006, A/chicken/Reshoty/02/2006, and A/duck/Tuva/01/2006 ranged from 2.7 to 3.0, while the virus A/common gull/Chany/P/2006 had a markedly lower IVPI of 1.7. The virus A/common gull/Chany/P/2006 had a unique pattern of six amino acid substitutions in the regions of viral proteins crucial for virulence of H5N1 viruses. We hypothesize that these substitutions may affect the pathogenicity of A/common gull/Chany/P/2006.

Reintroduction of highly pathogenic avian influenza A/H5N8 virus of clade 2.3.4.4. in Russia

In the spring of 2016, a loss of wild birds was observed during the monitoring of avian influenza virus activity in the Republic of Tyva. That outbreak was caused by influenza H5N8 virus of clade 2.3.4.4. In the fall, viruses of H5N8 clade 2.3.4.4 were propagated in European countries. This paper presents some results of analysis of the virus strains isolated during the spring and fall seasons in 2016 in the Russian Federation. The investigated strains were highly pathogenic for mice, and some of their antigenic and genetic features differed from those of an H5N8 strain that circulated in 2014 in Russia.

Highly pathogenic influenza H5N1 virus of clade 2.3.2.1c in Western Siberia

In the spring of 2015, avian influenza virus surveillance in Western Siberia resulted in isolation of several influenza H5N1 virus strains. The strains were isolated from several wild bird species. Investigation of biological features of those strains demonstrated their high pathogenicity for mammals. Phylogenetic analysis of the HA gene showed that the strains belong to clade 2.3.2.1c.

Characterization of the H5N1 influenza virus isolated during an outbreak among wild birds in Russia (Tuva Republic) in 2010

A study of the basic biological properties of H5N1 subtype strain isolated during an outbreak among wild birds in Russia in 2010 is presented. The study was carried out using conventional methods according to the WHO recommendations. H5N1 influenza virus isolated in Siberia belonged to clade 2.3.2 of the hemagglutinin gene, and phylogenetic analysis was performed. The antigenic characteristics and the basic genetic markers of biological properties were studied. It was shown that all strains were highly pathogenic for chickens and white mice. Thus, it was shown that, in Russia, the 2010 H5N1 virus phylogenetically closely related to Asian variants caused epizootic among wild birds. The potential danger of this variant of the virus for humans was confirmed by different methods. We discussed the possibility of formulating the natural focus of H5N1 influenza.

Herd immunity and fatal cases of influenza among the population exposed to poultry and wild birds in Russian Asia in 2013–2014

In total 1,525 blood serum samples were collected in October, 2013 in Russian Asia from people who reside in territories that are at high risk for emergence of influenza viruses with pandemic potential. Presence of antibodies to influenza viruses in the sera was tested in hemagglutination inhibition test. None of the samples produced positive results with the antigens A/H5 and A/H7. Twelve strains of influenza A(H1N1pdm09) virus were isolated from people who died presumably from influenza during 2013–2014 epidemic season. All strains were similar to vaccine strain A/California/07/09 according to their antigenic properties and sensitivity to anti‐neuraminidase drugs (oseltamivir and zanamivir). Genetic analysis revealed that all strains belong to group 6, subgroup 6B of influenza A(H1N1)pdm09 virus. Substitutions in HA1: S164F add E235K as well as E47G, A86V, K331R, N386K, N397K in NA, and K131E, N29S in NS1, and N29S, R34Q in NEP separate investigated strains into two groups: 1st group—A/Chita/1114/2014, A/Chita/1115/2014, A/Chita/853/2014, A/Barnaul/269/2014 and 2nd group—A/Chita/655/2014, A/Chita/656/2014, A/Chita/709/2014, A/Chita/873/2014. Mutation D222G in HA1, which is often associated with high morbidity of the illness, was present in strain A/Novosibirsk/114/2014. Substitution N386K in NA removes a potential N‐glycosylation site in neuraminidases of A/Chita/1114/2014, A/Chita/1115/2014, A/Chita/853/2014, A/Barnaul/269/2014, A/Novosibirsk/114/2014, and A/Blagoveshensk/252/2014. J. Med. Virol. 88:35–44, 2016.

Isolation and molecular characterization of the influenza A/H5N1 viruses isolated during the outbreaks of avian influenza among birds in the European part of Russia in 2005: a virus strain with ozeltamivir-resistance mutation was found

The isolation and characterization of the influenza A/H5NI viruses isolated from hens that died during the outbreak of avian influenza in autumn 2005 in the Yandovka village (Tula oblast) and from a wild swan that died near the orifice of the Volga River in the zone of the Karalat Furrow were carried out. Molecular-biologic and phylogenetic analyses were performed with a view of determining possible geographical origin of strains, phylogenetic similarity of viruses and also estimating their pathogenicity, epidemic danger for people, and possible resistance to antiviral drugs. It was shown that the virus belonged to the high pathogenic variants that arose in China as a result of the reassortment of the viruses of the genotypes Z and V that circulated among poultry and wild birds. A number of molecular markers characterizing the high pathogenicity of the virus for gallinaceous birds and mammals were revealed, but the specific mutations in the hemagglutinin gene that promote the high rate of virus replication in a human organism and also the mutations of adaptation to it were not found. It was shown that the variants of the influenza A/H5N1 virus that circulated in this epizootic were sensitive to remantadine. The strain isolated from the wild swan had the mutation causing resistance to Tamiflu/ozeltamivir.

Humoral immunity to influenza in an at-risk population and severe influenza cases in Russia in 2016–2017

This work aimed to analyze the herd immunity to influenza among a Russian population living in regions with an increased risk of emergence of viruses with pandemic potential, and to isolate and investigate virus strains from severe influenza cases, including fatal cases, during the 2016–2017 epidemic season. In November 2016 – March 2017 highly pathogenic influenza outbreaks were registered in Russia among wild birds and poultry. No cases of human infection were registered. Analysis of 760 sera from people who had contact with infected or perished birds revealed the presence of antibodies to A(H5N1) virus of clade 2.3.2.1c and A(H5N8) virus of clade 2.3.4.4. The 2016–2017 influenza epidemic season in Russia began in weeks 46–47 of 2016 with predominant circulation of influenza A(H3N2) viruses. Strains isolated from severe influenza cases mainly belonged to 3C.2a.2 and 3C.2a.3 genetic groups. Up to the 8th week of 2017 severe influenza cases were often caused by influenza B viruses which belonged to 1A genetic group with antigenic properties similar to B/Brisbane/60/2008. All influenza A and B virus strains isolated in the 2016–2017 epidemic season were sensitive to oseltamivir and zanamivir.