[Correlation between the receptor specificity of pandemic influenza A (H1N1)pdm09 virus strains isolated in 2009-2011 and the structure of the receptor-binding site and the probability of fatal primary viral pneumonia].

The receptor specificity (RS) of pandemic influenza A(H1N1) pdm09 virus strains deposited into the State Collection of Viruses of the Russian Federation, D. I. Ivanovsky Research Institute of Virology, Ministry of Health and Social Development of Russia, in the 2009-2010 and 2010-2011 epidemic seasons to a panel of 9 sialoglycopolymers (SGP). The strains were divided into 3 groups according to the W(3/6) index proposed by the authors, which was equal to the amount of reactivities to unbranched alpha2-3-SGP to that of reactivities to unbranched alphal-6-SGP: W(3/6) < or = 1.0; 1.0 < W(3/6) < or = 1.5. The W(3/6) < or = 1.5 group showed a predominance of a2-3-RS, attended by the high incidence of fatal primary viral pneumonias (FPVP) (60.0%) and amino acid replacements in the HA1 receptor-binding site (RBS) (80.0%): D222{G, N} and Q223R. The 1.0 < W(3/6) < or = 1.5 group was characterized by mixed alpha2-3/alpha2-6-RS with the incidence of FPVP (29.7%) and amino acid replacements in the HA1 RBS (40.5%) (D222{G, N, V} and Q223), respectively. In the W(3/6) < or = 1.0 group, alpha2-6-RS was prevalent, FPVPs were absent and amino acid replacements in HA1 RBS (D222{G, E}) were seen only in 6.0% of cases. The number of strains with increased specificity to alpha2-3-sialosides increased in the 2010-2011 epidemic season as compared to the previous season. With their further spread among the population, there may be a rise in cases of severe primary viral pneumonias with possible fatal outcomes, which can be, however, accompanied by a decrease in the capacity of mutants to air-dropwise transmission.

[A possible association of fatal pneumonia with mutations of pandemic influenza A/H1N1 sw1 virus in the receptor-binding site of the HA1 subunit].

The paper gives the results of sequence analysis of 150 positive samples in real-time RT-PCR, including 47 autopsy materials from patients (including 10 pregnant women), who died from fatal pneumonia mainly in November-December 2009, in whom the lifetime etiological diagnosis had not been made and hence no early etiotropic therapy performed. 70% of the primary materials from the deceased patients were found to have pandemic influenza A(H1N1) v mutants in the lung tissue with D222G (15%), D222N (15%), D222E (2%) substitutions, as well as a mixture of mutants (38%). Nasopharyngeal lavages from 3 Chukotka deceased patients exhibited only consensus (nonmutant) D222 virus variants; there was a mixture of consensus and mutant virus variants in the trachea and a mixture of mutant ones in the lung. Preliminary data from the study of the interaction of the hemagglutinin of two strains having D222G and D222N mutations with 9 oligosaccharides imitating the variants of cell receptors for influenza A virus suggest that there is a double receptor specificity for alpha2'-3' and alpha2'-6'-sialosides with a preponderance of alpha2'-3'-specificity. Further spread of the mutants that have acquired a high virulence and preserved their capacity for the respiratory route of human infection may lead to the situation similar to that seen in the 1918-1919 pandemic. Another scenario for evolution of the virus is to preserve its receptor specificity for alpha2'-3'-sialosides and high virulence with losses of alpha2'-6' specificity and capacity for aerosol transmission, by damping the pandemic.

[Detection of amino acid substitutions of asparaginic acid for glycine and asparagine at the receptor-binding site of hemagglutinin in the variants of pandemic influenza A/H1N1 virus from patients with fatal outcome and moderate form of the disease].

The paper analyzes the amino acid sequence of the receptor-binding site of hemagglutinin (HA) in the variants of pandemic influenza A/H1N1 swl from 18 patients with moderate (n=1) and fatal (n=17) forms of the disease in 2009. Nine samples contained asparaginic acid at position 222 of HA1 (D). This site exhibited mutations in 9 samples: D222G (n=3), D222N (n=3), and D222G/D222N (n=3). In one patient with the moderate form of the disease, D222G mutation was revealed after the second passage in the developing chick embryos; this mutation was not found in the primary sample from the patient. The findings suggest the mutant variants of the virus start to circulate among the population, which requires, firstly, continuation of molecular virological monitoring of the pandemic situation and, secondly, further study of the impact of amino acid substitutions at the receptor-binding site of HA1 on the increased virulence of influenza A virus.

[Isolation of influenza virus A (Orthomyxoviridae, Influenza A virus), Dhori virus (Orthomyxoviridae, Thogotovirus), and Newcastle's disease virus (Paromyxoviridae, Avulavirus) on the Malyi Zhemchuzhnyi Island in the north-western area of the Caspian Sea].

The paper presents the results of the 2003 and 2006 environmental virological monitoring surveys on the Malyi Zhemchuzhnyi Island where a large breeding colony of sea gull (Laridae) is located. In the past several years, expansion of cormorants (Phalacrocorax carbo) has enhanced the intensity of populational interactions. The investigators isolated 13 strains of influenza A virus (Orthomyxoviridae, Influenza A virus) subtype H13N1 (from sea gulls (n = 4), cormorants (n = 9) 1 strain of Dhori virus (Orthomyxoviridae, Thogotovirus) from a cormorantwith clinical symptoms of the disease, 3 strains of Newcastle disease virus (Paramyxoviridae, Avulavirus) from cormorants. RT-PCR revealed influenza A virus subtype H5 in 3.1% of the cloacal lavages from cormorants. Neutralization test indicated that sera from cormorants contained specific antibodies against West Nile (Flaviviridae, Flavivirus) (15.0%), Sindbis (Togaviridae, Alphavirus) (5.0%), Dhori (10.0%), and Tahini (Bunyaviridae, Orthobunyavirus) (5.0%); sera from herring gulls had antibodies against Dhori virus (16.7%); there were no specific antibodies to Inco (Bunyaviridae, Orthobunyavirus) and mountain hare (Lepus timidus) (Bunyaviridae, Orthobunyavirus) virus.

[Highly pathogenic influenza A/H5N1 virus-caused epizooty among mute swans (Cygnus olor) in the lower estuary of the Volga River (November 2005)].

Molecular virological studies of the field material collected in the epicenter of epizooty with high mortality among mute swans (Cygnus olor) in the area of the lower estuary of the Volga River (November 2005) could establish the etiological role of highly pathogenic influenza A (HPAI) virus of the subtype H5N1. Ten HPAI/H5N1 strains deposited at the State Collection of Viruses of the Russian Federation with the priority dated December 1, 2005 were isolated from the cloacal/tracheal swabs and viscera of sick and freshly died mute swans. Complete nucleotide sequences of all fragments of the genome of 6 strains have been deposited in the Gene Bank. The paper discusses the molecular genetic characteristics of isolated strains.

[Circulation of West Nile virus (Flaviviridae, Flavivirus) and some other arboviruses in the ecosystems of Volga delta, Volga-Akhtuba flood-lands and adjoining arid regions (2000-2002)]. / Osobennosti tsirkuliatsii virusa Zapadnogo Nila (Flaviviridae, Flavivirus) i nekotorykh drugikh arbovirusov v ékosistemakh del'ty Volgi, Volgo-Akhtubinskoi poimy i sopredel'nykh aridnykh landshaftakh (2000-2002 gg.).

Comprehensive virological, serological as well as genetic studies of the ecology of West Nile Virus (WNV) as well as of some other arboviruses were undertaken in different ecosystems in the territories of the Astrakhan Region and of the Kalmyk Republic. The main carriers (mosquitoes, ticks, birds and mammals) were defined as involved in the circulation of viruses within the natural and anthropogenic biocenosis. Phylogenetic examinations of isolated strains and samples, which were positive in RT-PCR, showed an absolute predominance of genotype I virus that was most closely related to American and Israeli strains. At the same time, epidemic strains had up to 6% of nucleotide differences versus the historic strains isolated in the same region 20-30 years ago. Besides, the circulation of genotype IV was discovered; it was characterized by a lower pathogenicity, which, possibly, ensures the shaping of a pronounced immune interlayer bearing no epidemic consequences. An analysis of the study results on the WNV ecology denotes the epicenter of the endemic territory located in the middle part of the Volga delta.

[An intrahospital outbreak of HIV infection in Elista]. / Vnutribol'nichnaia vspyshka VICh-infektsii v Eliste.

For the first time a nosocomial focus of HIV infection was established. Out of 83,000 inhabitants of the Kalmyck ASSR who underwent planned examination in the course of epidemiological investigation, 65 cases of HIV infection were detected and all of them were traced to the focus of hospital infection (56 children and 9 adults: 1 man and 8 women; of these, 7 women contacted the infection from their infected children in the process of breast feeding). The children were infected during their stay in two hospitals of Elista where they received multiple intravenous and intramuscular injections. The infection spread from the infant department of the regional pediatric hospital to 4 more departments and to the infectious diseases hospital. Transmission of this infection was maintained for several months by the use of nonsterile syringes in parenteral manipulations.