Detection of the circulation of Crimean-Congo hemorrhagic fever virus in the piedmont steppes of the North Caucasus

The laboratory verified cases of Crimean-Congo hemorrhagic fever (CCHF) in the piedmont steppes of the North Caucasus (Malgobeksky District, Republic of Ingushetia) are first described. The source of the first infection was Ixodidae ticks; three subsequent sources were contacts with the bloody discharges from patients. CCHF virus genome was detected in the blood of the cattle from an epidemic focus and in the pools of the Ixodes ticks Haemaphysalis parva Neum., 1897 and Boophilus annulatus Say, 1821, taken from cattle. The problem of including the piedmont steppes of the North Caucasus into the CCHF nosological area is discussed.     

Algorithm for predicting development of HIV infection

Described in the paper are the results of a 15-year monitoring (1986-2001) of HIV patients at the Clinic of the Institute of Immunology, Federal Department "Medbioextreme", Russia's Health Ministry. The gathered experimental data, including the immunologic, biochemical and general-clinical parameters, were comprehensively analyzed. Optimal schemes of complex HIV monitoring were designed to ensure a comparative and dynamic study of different clinical-and-laboratory indices for the purpose of defining the HIV-induced pathogenesis specificity and adequate therapeutic approaches.     

Ecology and evolution of influenza viruses in Russia (1979-2002)

The research results on ecology and evolution of influenza A viruses, which has been conducted by the Center of Ecology and Evolution of influenza Viruses of Ivanovsky's Institute of Virology, Russian Academy of Medical Sciences, for more than 30 years, are summarized in the paper. A gene pool of influenza A viruses circulating in Russia's territory was defined. Foci of influenza A viruses were detected in natural biocenosis. Issues conditioned by the population interrelations of influenza viruses, i.e. between the populations of wild and home animals and the populations of people, are also under discussion.     

Effect of Zanamivir substance on infection induced by highly pathogenic avian influenza A/H5N1 in cell cultures

In vitro experiments revealed that Zanamivir substance had high antiviral activity against infection induced by genotypes 2.2 and 2.3.2 of highly virulent influenza A/H5N1 virus in the porcine embryonic renal epithelial (PERE) cell cultures. Zanamivir at used concentrations (1.0 microg/ml or lower) had no cytotoxic properties and was equally highly effective when used for prevention (1 hour prior to cell inoculation), treatment-and-prevention (at the time of cell inoculation), and treatment (2 hours after inoculation). The high antiviral potential of Zanamivir was shown in the experiments dealing with its effect on the ability of infected PERE cells to produce an infectious virus in the first 24 hours after inoculation. The findings suggest that Zanamivir (Relenza) shows promise as an effective antiinfluenza agent.     

West Nile virus infection of agricultural animals in the Astrakhan region, as evidenced by the 2001-2004 serological surveys

Sera sampled from 2,884 farming animals in the Astrakhan region in 2001 to 2004 were investigated by the hemagglutination inhibition test (HIT) in order to indicate specific antibodies to West Nile virus (WNV). HIT-positive samples were investigated by the neutralization test (NT). WNV antibodies were detected in all the examined species of animals: horses (the proportion of positive tests throughout the observation averaged 9.8%; the agreement with NT results was 94.1%), cattle (6,4 and 72.%), camels (5.2 and 41.7%), pigs (3.1 and 75%), and sheep (2.2 and 57.1). Relationships between the environmental features of WNV in different natural zones, the infection rate, and the conditions of keeping farming animals in the Astrakhan region are analyzed.     

Isolation of influenza A/H5N1 virus strains from poultry and wild birds in West Siberia during epizooty (July 2005) and their depositing to the state collection of viruses (August 8, 2005)

Six strains of influenza AH5N1 virus were isolated, by using PS and MDCK continuous cell lines from poultry and wild birds, which were collected on July 28, 2005 in the samples taken from 5 examines species of wild birds in the Novosibirsk region during the epizootic outbreak with a high mortality. The strains were identified by means of HIT, RT-PCR, and microchip-based techniques. Two strains, A/Grebe/Novosibirsk/29/05 (H5N1) and A/Duck/Novosibirsk/56/05 (H5N1), were deposited to the Russian State Collection of Viruses (Registration Nos. 2372 and 2371, respectively) with the priority date 08.08.2005. Positive results in RT-PCR for influenza A/H5N1 virus detec- tion were obtained in 100% of the samples from dead and sick poultry; 93% from the clinically healthy poultry kept together with sick one; positive results ranged from 0 to 36%. Sequencing established the identity of genetic characteristics of strains isolated for wild birds and poultry as well as their affiliation to high pathogenic avian influenza (HPAI). Phylogenetic analysis revealed a high homology of hemagglutining of West-Siberian strains and strains isoolated from bar-headed gooses (Eulabeia indica) on the Qinghai Lake (Western China) in the 2005 spring.     

Molecular genetic analysis of the biological properties of highly pathogenic influenza A/H5N1 virus strains isolated from wild birds and poultry during epizooty in Western Siberia (July 2005)

The full-size genomes of 2 highly pathogenetic avian influenza (HPAI) virus strains isolated from a wild great-crested grebe (A/Grebe/Novosibirsk/29/05) and a domestic duck (A/Duck/Novosibirsk/56/05) in the tract of the Chany hollow, Barabino forest-steppe (Novosibirsk Region) during the epizootic outbreak in the summer of 2005. The reproductive properties of these strains successively increase in the series of cell lines BHK-2 --> LEH --> Vero-E6 --> MDCK --> PS. A/Grebe/Novosibirsk/29/05 and A/Duck/Novosibirsk/56/05 were shown to be genetically close in all genomic segments to both each other and a group of HPAI/H5N1 A/Qinghai 05 strains isolated from wild birds on the Kukunor Lake in the northwestern province of Tsinkhai, China, in May 2005. All the above strains have the HPAI/H5-specific amino acid sequence of a proteolytic cleavage site (PQGERRRKKRGLF) with Lys-627 in the protein PB2 (which is associated with increased virulence to mammalian cells), Glu-92 in the protein NS1 (that suppresses an antiviral response in the host), Ser-31 in M2 (that is a marker of rimantadine/amantadine sensitivity), 20-member amino acid deletion in the protein NA (positions 49-68) that is a marker of affiliation to the so-called genotype Z and of increased tropism to poultry.     

Isolation of highly pathogenic avian influenza (HPAI) A/5H5N1 strains from wild birds in the epizootic outbreak on the Ubsu-Nur Lake (June 2006) and their incorporation to the Russian Federation State Collection of viruses (July 3, 2006)

Virological and molecular genetic studies of the field material collected in the epicenter of epizooty with high mortality rates among the wild birds on the coast of the Ubsu-Nur lake (Republic of Tyva, 51 degrees NL, 93 degrees EL, June 2006) revealed the etiological role of highly pathogenic avian influenza (HPAI) H5N1. Seven HPAI/H5N1 strains were isolated from the tracheal/cloacal swabs of clinically healthy, ill and recently dead great-crested grebes (Podiceps cristatus), cormorants (Phalacrocorax carbo), balt-coots (Fulica atra), and common terns (Sterna hirundo) collected on June 24, 2006, and incorporated to the RF State Collection of Viruses (with the July 3, 2006 priority). Full-length genome nucleotide sequences were incorporated to the GenBank (with the July 23, 2006 priority) (DQ852600-DQ852607). Comparative analysis of molecular genetic characteristics showed their belonging to the Qinghai-Siberian genotype. The strains were sensitive to rimantadine.     

Characterization of epidemic influenza virus A(H3N2) strains circulating in Russia in the 2003-2004 epidemic season

Studies indicated that the epidemic rise in the incidence of influenza was caused by its virus A (H3N2) circulation in Russia in the 2003-2004 season. The Center of Influenza Ecology and Epidemiology investigated 101 epidemic strains isolated the MDCK culture. Antigenic analysis showed that all viruses A(H3N2) were similar to the reference virus A/Fujian/411/02(H3N2) and only 5 strains slightly differed from the latter. Twelve (14%) strains resistant to rimantadine at a concentration of 0.5 mg/ml were identified. Investigation of paired sera from the patients demonstrated a rise of antibodies to the references of influenza virus A(H3N2) in 68.7% of cases and a less increase in those to influenza viruses A(H1N1) and B. The active circulation of A(H3N2) viruses was due not only to changes in their antigenic structure, but also to the low level of antibodies to these viruses, as shown by the analysis of donor sera.     

Clinico-immunologic monitoring of HIV-infected patients: comparative analysis of indicators, characterizing development of the disease

The paper contains the results of a 15-year monitoring (since 1986 to 2001) of HIV-infected patients followed up at the clinic of the Institute of Immunology, Federal Department "Medbioextrem", Russia's Health Ministry. An analysis of a category of HIV-infected persons, who practiced the intravenous consumption of drugs since 1997 to 2001, revealed not only concomitant multi-virus infections (hepatitis C--68%, hepatitis B--48%, herpes 41%, fungal infections--66% and bacterial infections--46%) but also lesions (up to 70%) in the gastrointestinal tract and in the hepatic-cellular and hepatic-biliary systems. It was established that, when only immunological indices are taken account of in presence of multi-virus infections, it does not ensure an adequate evaluation of an HIV-patient condition. The below biochemical parameters must be necessarily taken into consideration: activity of alanine aminotransferase, aspartate aminotransferase and of alkaline phosphatase. The changes in the biochemical parameters were shown to be essentially higher in HIV patients with hepatitis C virus (HCV) even during the 2 initial follow-up years, when the immunological parameters are in the norm or even insignificantly below it. A comparative analysis of dynamic clinical, immunological and biochemical indices was made within the case study for the purpose of defining the prognostic criteria for HIV progression scenarios.