[Association of polymorphic variants of hemostatic system genes with the course of COVID-19]

INTRODUCTION

  COVID-19 is characterized by a varied clinical course. The aim of the work was to identify associations of SNPs of hemostatic system genes with COVID-19.

MATERIALS AND METHODS

DNA was isolated from patients (n=117) and healthy participants (n=104). All infected patients were divided into 3 groups, depending on disease severity assessment, which was appreciated by NEWS2. Another group consisted of participants, who had asymptomatic infection in the past. Determination of SNPs of the genes FGB (-455 G/A), FII (20210 G/A), FV (1691 G/A), FVII (10976 G/A), FXIIIA1 (103 G/T), ITGA2 (807 C/T), ITGB3 (1565 T/C), SERPINE1 (-675 5G/4G) were performed by PCR using the "Genetics of Hemostasis" kit ("DNA-Technology", Russia).

RESULTS

In analyzed SNPs, no significant differences were detected between the group of infected patients and healthy participants. But significant association was revealed in gene SERPINE1 (-675 5G/4G), when patient groups, differing in the disease severity, were analyzed relative to the group of participants with asymptomatic infection (p=0.0381; p=0 .0066; p=0.0009). It was found, that as COVID-19 severity scores increased, the proportion of 5G allele of gene SERPINE1 decreased, and the proportion of the 4G allele increased (p=0.005; p=0.009; p=0.0005). Similar processes were observed for genotypes 5G/5G and 4G/4G.

DISCUSSION

The gene SERPINE1 (-675 5G/4G) is associated with the severity of COVID-19.

CONCLUSION

For the first time, it was discovered that 5G/5G genotype of gene SERPINE1 (-675 5G/4G) can be a marker of a milder course of COVID-19, and the 4G/4G genotype as a more severe one.

[Adamantan derivatives capable of inhibiting the reproduction of a Rimantadine resistant strain of influenza A(H1N1)pdm09 virus (Influenza A virus, Alphainfluenzavirus, Orthomyxoviridae).]

INTRODUCTION

Adamantanthane-type drugs such as rimantadine and amantadine have long been used to treat diseases caused by influenza A virus. However, as a result of the mutations, influenza viruses have become resistant to aminoadamantans. The target for these drugs was the protein channel M2. Influenza A virus M2 viroporin in the protein shell forms fairly specific ion channels with a diameter of about 11 Å, specializing in transporting protons inside the viral particle (virion). Restoration of the antiviral properties of adamantanthane-type drugs consists in the selection of advanced functional groups bound by the carbocycle to find new sites of binding to the protein target M2. The purpose of the study is to identify the antiviral properties of new adamantanum derivatives to the pandemic strain of influenza A virus in vitro.

MATERIAL AND METHODS

Compounds of aminoadamantans with amino acids and other organic molecules were obtained by classical peptide synthesis methods. The structure of the compound was tested by means of physical and chemical methods. Antiviral properties of synthetic compounds were studied in vitro on monolayer MDCK cells infected with pandemic strain of influenza A/California/07/2009 virus in two schemes of administration of investigated compounds and virus.

RESULTS

The reference strain of the influenza virus A/California/07/2009(H1N1) was sensitive to the compounds under test in varying degrees. The antiviral activity of the compounds was expressed in a 50% inhibitory concentration (IС₅₀) ranging from 0.5 to 2.5 мкM, which is generally a good indicator for the Rimantadine/Amantadine resistant strain.

DISCUSSION

The values of the IС₅₀ for compounds introduced two hours before contact with the virus were slightly higher than those for single-moment introduction of the substance and virus. The effect of increasing the inhibitory concentration in the prophylactic scheme of compounds was valid for all compounds of the experiment.

CONCLUSION

The presented synthetic compounds are active against the variant of influenza A virus resistant to Rimantadine and Amantadine preparations. The obtained compounds can be used as model structures for creation of a new drug of direct action against advanced strains of influenza A virus.

[Peculiarities of the influenza and ARVI viruses circulation during epidemic season 2019-2020 in some regions of Russia]

INTRODUCTION

The surveillance of influenza viruses in ARVI structure and study of their properties in epidemic season 2019-2020 in Russian Federation are actual for investigations due to tasks of Global Influenza Strategy initiated by WHO in 2019.

MATERIAL AND METHODS

The data of epidemiological surveillance on influenza- and ARVI-associated morbidity and hospitalization in different age groups of population were analyzed; virological, genetic and statistical methods were used.

RESULTS

Preschool children were involved in epidemic the most. Meanwhile, the highest rate of hospitalization was observed in patients of 18-40 years old. Influenza A(H1N1)pdm09 virus dominated in etiology of ARVI in hospitalized patients and pneumonia. The role of respiratory viruses in severe cases of pneumonia and bronchoalveolar syndrome in children was shown. The differences in spectrum of circulating viruses caused ARVI in different regions of Russia were found. Influenza A(H1N1)pdm09 and B/Victoria-like viruses were the main etiological agents that caused of epidemic; its activity among all ARVI was 7.3 and 8.0%, respectively. The differences in antigenic properties of influenza A(H3N2) and B epidemic strains compared to vaccine viruses were found. The populations of epidemic strains were presented by following dominant genetic groups: 6B1.A5/183P for A(H1N1)pdm09, 3С.2а1b+137F for A(H3N2) and V1A.3 line B/Victoria-like for B viruses. The good profile of epidemic strains susceptibility to anti-neuraminidase inhibitors has been saved. The most of the studied influenza strains had the receptor specificity characteristic of human influenza viruses.

CONCLUSIONS

Obtained results identified the peculiarities of viruses caused the influenza and ARVI in epidemic season 2019-2020 in different regions of Russia. These results suggested the important role of influenza A(H1N1) pdm09 in severe cases and pneumonia in adults 18-40 years old. The continuing drift in influenza viruses was found, which, apparently, could not but affect the efficacy of vaccine prophylaxis and was also considered in the recommendations of WHO experts on the composition of influenza vaccines for the countries of the Northern Hemisphere in the 2020-2021 season.

[Evolution of pandemic influenza virus A(H1N1)pdm09 in 2009-2016: dynamics of receptor specificity of the first hemagglutinin subunit (HA1).]

INTRODUCTION

The new reassortant of the swine flu virus A(H1N1)pdm09, which emerged in 2009, overcame the species barrier and caused the 2009-2010 pandemic. One of the key points required for the influenza virus to overcome the species barrier and adapt it to humans is its specific binding to the receptors on the epithelium of the human respiratory tract.

PURPOSE

Studying the dynamics of changes in receptor specificity (RS) of the HA1 subunit of the hemagglutinin of the influenza A(H1N1)pdm09 virus strains isolated during the period 2009-2016 on the territory of the Russian Federation, and an analysis of the possible impact of these changes on the incidence rates of the population of the Russian Federation of pandemic influenza in certain epidemic seasons.

MATERIAL AND METHODS

Standard methods of collecting clinical materials, isolation of influenza viruses, their typing and genome sequencing were used. For the study of RS of influenza A virus (H1N1)pdm09, the method of solid phase sialosidenzyme analysis was used.

RESULTS

It is shown that the change in the parameter W_3/6 , which characterizes the degree of a2-3 receptor specificity (a2-3-RS) of the influenza virus A(H1N1) pdm09 over a2-6-RS, coincides with the change in the incidence rates of the Russian Federation's pandemic flu in separate epidemic seasons. There is a tendency to increase the affinity of the virus A(H1N1)pdm09 to α2-3 analogs of the sialyl-glycan receptors of the human respiratory tract epithelium - α2-3-sialoglycopolymers (α2-3-SGP), and falls to α2-6-SGP, with the virus showing the greatest affinity for sulfated sialoglycopolymers.

DISCUSSION

Screening for RS strains of influenza A (H1N1)pdm09 virus isolated on the territory of the Russian Federation in 2009-2016 revealed a decrease in the affinity of viruses for a2-6-sialosides, especially for 6'SL-SGP, which is probably due to the presence of amino acid substitutions in the 222 and 223 positions of RBS HA1 viruses. Previous studies have shown that the presence of such substitutions correlates with an increase in the virulence of the influenza A virus (H1N1)pdm09 [16, 23]. Probably, the pandemic virus has evolved towards the selection of more virulent pneumotropic variants.

CONCLUSION

Monitoring of the receptor specificity of a pandemic influenza virus makes it possible to identify strains with altered RS to the epithelium of the human respiratory tract and an increased ability to transfer from person to person. Change in the period 2009-2016 the W_3/6 parameter characterizing the degree of α2-3-RS excess of the influenza A(H1N1)pdm09 virus over α2-6-RS, coincides with the change in the incidence rates of the pandemic influenza population of the Russian Federation in certain epidemic seasons.

Etiology of epidemic outbreaks COVID-19 in Wuhan, Hubei province, Chinese People Republic associated with 2019-nCoV (Nidovirales, Coronaviridae, Coronavirinae, Betacoronavirus, Subgenus Sarbecovirus): lessons of SARS-CoV outbreak

Results of analysis of phylogenetic, virological, epidemiological, ecological, clinical data of COVID-19 outbreaks in Wuhan, China (PRC) in comparison with SARS-2002 and MERS-2012 outbreaks allow to conclude:

– the etiological agent of COVID-19 is coronavirus (2019-CoV), phylogenetically close to the SARS-CoV, isolated from human, and SARS-related viruses isolated from bats (SARS-related bat CoV viruses). These viruses belong to the Sarbecovirus subgenus, Betacoronavirus genus, Orthocoronavirinae subfamily, Coronaviridae family (Cornidovirinea: Nidovirales). COVID-19 is a variant of SARS-2002 and is different from MERS-2012 outbreak, which were caused by coronavirus belonged to the subgenus Merbecovirus of the same genus;

– according to the results of phylogenetic analysis of 35 different betacoronaviruses, isolated from human and from wild animals in 2002-2019, the natural source of COVID-19 and SARS-CoV (2002) is bats of Rhinolophus genus (Rhinolophidae) and, probably, some species of other genera. An additional reservoir of the virus could be an intermediate animal species (snakes, civet, hedgehogs, badgers, etc.) that are infected by eating of infected bats. SARS-like coronaviruses circulated in bats in the interepidemic period (2003-2019);

– seasonal coronaviruses (subgenus Duvinacovirus, Alphacoronavirus) are currently circulating (November 2019

– January 2020) in the European part of Russia, Urals, Siberia and the Far East of Russia, along with the influenza viruses A(H1N1)pdm09, A(H3N2), and В, as well as six other respiratory viruses (HPIV, HAdV, HRSV, HRV, HBoV, and HMPV)

[The 2015-2016 epidemic season in Russia and the world: Circulation of influenza viruses, trends in incidence, clinical aspects, and treatment algorithm]

In the 2015-2016 epidemic season, there were dominant influenza A(H1N1)pdm09 strains (over 90%) among the circulating influenza viruses in most countries of the Northern Hemisphere and in Russia. A study of the antigenic properties of influenza A(H1N1)pdm09 strains revealed no differences in those of vaccine virus. Sequencing showed that there were amino acid substitutions in hemagglutinin (receptor binding and Sa sites) and in the genes encoding internal proteins (PA, NP, M1, and NS1). The rise in the incidence in the Russian Federation, which was etiologically associated with influenza viruses, was registered in January-February 2016 with its maximum being observed at 4-5 weeks of 2016. Within the framework of the epidemiological surveillance of circulating influenza viruses in the Russian Federation, which was conducted by the WHO European Office, the D.I. Ivanovsky Institute of Virology, Honorary Academician N.F. Gamaleya Federal Research Centre for Epidemiology and Microbiology, Ministry of Health of Russia, and the Research Institute of Influenza, Ministry of Health of Russia, monitored at the Infectious Diseases Hospital One (IDH-1), Moscow Healthcare Department. Among 1491 examinees, influenza was verified in 104 (21.3%) adults, 208 (42.5%) pregnant women, and 177 (36.2%) children. Influenza A(H1N1)pdm09 was more often diagnosed in the age group of 15-40 years (63.7%); the proportion of influenza patients aged over 50 years increased (22.1%). Most adult patients had moderate influenza; pneumonia complicated the disease in 27.4%. Influenza in the pregnant women was complicated by pneumonia in 4.8% of cases. Influenza was more frequently diagnosed in infants and preschool children aged 0 to 3 years (42.9%), 4 to 6 years (41.2%), and older (15.9%), namely: 7-9 years (10%) and 10-12 years (5.9%). Influenza in the children was complicated by acute tonsillitis (19.4%) and varying degrees of laryngeal stenosis (12.4%). Bronchial obstructive syndrome developed in 2.5%, the rate of pneumonia was 6.2%. Antiviral therapy (AVT) in the early stages of the disease reduces the risk of its severity, the frequency of secondary complications, and the duration and degree of clinical symptoms of influenza. AVT with oseltamivir, zanamivir, imidazolyl ethanamide pentandioic acid (ingavirin), and interferon-a2b (viferon) has been performed in the patients hospitalized at Moscow IDH-1 in the 2015-2016 epidemic season.

FEATURES OF EPIDEMIC PROCESS OF INFLUENZA A(H1N1)PDM09 AND A(H3N2) IN RUSSIA FROM 2009 TO 2017

The goal of this work is to compare the key parameters of influenza epidemics of different etiology. Four epidemics of influenza with predominance of influenza A(H1N1)pdm09 and 4 epidemics of influenza A(H3N2) were analyzed using the database of the Federal State Research Institute of Influenza on morbidity, hospitalization, deaths from influenza in 59 cities in the period from 2009 to 2017. The intensity of epidemics involving the influenza A(H1N1)pdm09 decreased from high to medium, while the intensity of epidemics of influenza A(H3N2) increased from low to medium. In the epidemic of influenza A(H1N1)pdm09 in the total population, the incidence of influenza and ARI decreased by a factor of 1.6, while the mortality among patients decreased by a factor of 1.7 in all age groups, except for those over 65 years, for whom the incidence and mortality increased by factors of 1.4 of 2.3, respectively. In the epidemic of A(H3N2), a trend for increasing morbidity and mortality was more pronounced among individuals older than 65 years. Pandemic influenza remains the leading cause of deaths. Among the dead in the epidemic of influenza A(H1N1)pdm09, the proportion of young individuals decreased (including a fourfold decrease of lethality in pregnant women), while the proportion of persons over 65 years increased 7.8 times; in the epidemic of influenza A(H3N2) only 2.5-fold increase was observed. In the epidemic of influenza A(H1N1)pdm09, the proportion of lethality increased among people with cardiovascular diseases and diseases of the internal organs; in the epidemic of influenza A(H3N2), the proportion of lethality increased among people with immunodeficiency, diseases of the internal organs and respiratory system.

DRIFT OF INFLUENA A(H3N2) VIRUS: BIOLOGICAL, ANTIGENIC AND GENETIC PROPERTIES IN EPIDEMIC SEASON 2016-2017 IN RUSSIA AND COUNTRIES OF THE NOTHERN HEMYSPHERE

The article presents the features of the influenza virus circulation for the period from October 2016 to May 2017 in some territories of Russia collaborating with the D.I. Ivanovsky Institute of Virology, Federal State Budgetary Institution "N.F. Gamaleya Federal Research Centre for Epidemiology and Microbiology", Ministry of Health of the Russian Federation. One of the 2016-2017 season's peculiarities in Russia and countries of the Northern hemisphere was the earlier start of an increase in ARD morbidity with peak indexes reached towards the end of December 2016 - January 2017. First, influenza A(H3N2) virus was predominant; then, it was followed by influenza B virus activity observed until the end of the season. The indexes of morbidity were higher than in the previous season, while the rates of hospitalization and mortality were lower, lethal cases being detected in persons 65 years old and older. Epidemic strains of influenza A(H3N2) virus belonged to 3c.2a genetic group, reference strain A/Hong Hong/4408/2014, and its subgroup 3c.2a1, reference A/Bolzano/7/2016, that are antigenically similar. Strains of influenza B virus were antigenically similar to the B/Brisbane/60/2008 vaccine virus. Strains were sensitive to oseltamivir and zanamivir. The share participation of non-influenza ARI viruses was similar to preliminary epidemic seasons. WHO has issued recommendations for influenza virus vaccines composition for 2017-2018 for the Northern hemisphere.

DIAGNOSTIC CAPACITY OF DETECTION OF SPECIFIC ANTIBODIES TO PANDEMIC INFLUENZA A(H1N1)PDM09 VIRUS

Serologic studies occupy a significant place in influenza diagnosis. The article presents an analysis of the developed experimental version of ELISA test-systems for the detection of specific antibodies to the virus influenza A(H1N1)pdm09, and their dynamics at different stages of infection as compared with those of the traditional HAI method. The study included 20 paired samples of serum from patients hospitalized at different stages of the disease with etiology associated with the influenza virus A(H1N1)pdm09. Two groups were formed on the basis of HAI data, which showed the presence or absence of significant growth of specific antibodies to the influenza virus A(H1N1)pdm09. The control group consisted of 20 serum samples from individuals without influenza but with chronic hepatitis C. To examine the virus specific antibody two types of ELISA test systems were used. The first system was intended for the detection of IgM to the influenza virus A(H1N1)pdm09; the second was used for revealing specific IgG. The study showed the accuracy and specificity of detectable IgM and IgG to the virus influenza A(H1N1)pdm09. The dynamics of specific IgG titers in 15 of the 20 pairs of sera was reliable. The increase in titers was more pronounced than in the HAI. IgM against influenza virus could be detected up to 10 days, although reliable dynamics of these antibodies was not detected in paired samples. The test system was specific for the determination of both IgG and IgM antibodies to the influenza virus A(H1N1)pdm09 and significantly more sensitive than HAI. Using this ELISA test system, it is possible to monitor the dynamics of IgG to this virus even in the absence of diagnostic increases in antibody titers in HAI.

Virological, epidemiological, clinic, and molecular genetic features of the influenza epidemic in 2015-2016: prevailing of the influenza A(H1N1)09 pdm virus in Russia and countries of the Northern hemisphere

This work describes the specific features of the influenza virus circulating in the period from October 2015 to March 2016 in 10 cities of Russia, the basic laboratories of CEEI at the D.I. Ivanovsky Institute of Virology "Federal Research Centre of Epidemilogy and Microbiology named after the honorary academician N.F. Gamaleya" of the Ministry of Health of the Russian Federation. The increase in the morbidity caused by influenza viruses was detected in January-February 2016. The duration of the morbidity peak was 4-5 weeks. The most vulnerable group included children at the age from 3 to 6; a high rate of hospitalization was also detected among people at the age of 15-64 (65%). In clinic symptoms there were middle and severe forms with high frequency of hospitalization as compared with the season of 2009-2010, but much higher in comparison with the season of 2014-2015. Some of the hospitalized patients had virus pneumonias, half of which were bilateral. Among these patients, 10% were children; 30%, adults. The mortality in the intensive care unit of the hospital was 46%. Almost all lethal cases were among unvaccinated patients in the case of late hospitalization and without early antiviral therapy. The predominance of the influenza A(H1N1)09pdm virus both in the Russian Federation and the major part of the countries in the Northern hemisphere was noted. The results of the study of the antigenic properties of influenza strains of A(H1N1)pdm09 virus did not reveal any differences with respect to the vaccine virus. The sequencing data showed the amino acid substitutions in hemagglutinin (receptor binding and Sa sites) and in genes encoding internal proteins (PA, NP, M1, NS1). Strains were sensitive to oseltamivir and zanamivir and maintained resistance to rimantadine. The participation of non-influenza ARI viruses was comparable to that in preliminary epidemic seasons.

Amino acid polymorphism at residue 222 of the receptor-binding site of the hemagglutinin of the pandemic influenza A(H1N1)pdm09 from patients 166 with lethal virus pneumonia in 2012-2014

Survey data from autopsy specimens from patients who died from pneumonia caused by the influenza A(H1N1) pdm09 in 2012-2014 and mutant forms of influenza virus in these patients (position 222 in the receptor-binding region of hemagglutinin) were presented. In total, according to aggregate data, obtained with three different methods (sequencing, next-generation sequencing (NGS), virus isolation) mutant viruses were detected in 17 (41%) from 41 patients. The proportion of the mutant forms in viral populations ranged from 1% to 69.2%. The most frequent mixture was the wild type (D222) and mutant (D222G), with proportion of mutant type ranged from 3.3% to 69.2% in the viral population. Mutation D222N (from 1.1% to 5.5%) was found rarely. Composition of the viral population from one patient is extremely heterogeneous: in left lung there was only wild type D222, meantime in right lung - mixture of mutant forms 222D/N/G (65.4/32.5/1.1%), in trachea - mixture 222D/G/Y/A (61.8/35.6/1.2/1.4%, respectively), and in bronchi compound of 222D/G/N/A (64.3/33.7/1/1%, respectively) were detected. The obtained data indicate that the process of adaptation of the virus in the lower respiratory tract is coupled with the appearance of different virus variants with mutations in the receptor-binding region. Mutant forms of the virus are observed in the lower respiratory tract of the majority of patients with lethal viral pneumonia. However, if they are a minor part of the population, they cannot be detected by the method of conventional sequencing. They can be identified using the NGS methods.

[Comparative study of carbon nanotubes and polymer composites with silver as sorbents of the influenza A and B viruses]

The comparative examination of the interaction of the influenza A and B viruses and fragments of DNA with the carbon nanotubes--composites of polyaniline (PANI) nanotubes and granules containing Ag and without Ag was performed. The increased absorption of the allantois viruses and DNA was demonstrated in composites with Ag. The influence of temperature in the range of 4-36 degrees C was not found to be essential. The intensive absorption took place within the first 15 min of the contact with the sorbents. In total, the properties of the composites of PANI nanotubes + Ag 30% are the most promising for the influenza viruses and DNA absorption in water solutions.

[Serodiagnosis in the surveillance of the influenza virus circulation during the development of the pandemic caused by the A (H1N1)pdm09]

The goal of this work was to present the data of the study of the peculiarities of the generation factors of humoral immunity in the response to the infection with the pandemic influenza A (HIN1) pdmO9 in patients with different epidemiological anamnesis. High ability of the influenza viruses to spread over closed communities and the transfer of the maternal antibodies to babies, including a pandemic strain of the influenza virus A (H1N1) pdm09, was confirmed. The results of this study showed that the immune response to the surface antigens of the influenza virus (hemagglutinin and neuraminidase) was formed during the natural infection with the pandemic strains of the influenza A (H1N1) pdm09 in more than a half of the cases simultaneously.

[Comparison of the influenza epidemics in Russia caused by the pandemic virus A(H1N1)pdm09 within the period from 2009 to 2013]

Comparative analysis of the three past epidemics with the participation of the pandemic influenza A(H1N1)pdm09 was conducted according to the results of the epidemiological trials of two WHO National influenza centers for the morbidity, hospitalization, and mortality of the influenza in 59 cities of Russia for the period from 2009 to 2013. The first wave of the pandemic of 2009 was the most severe. Compared with this wave, during the next epidemics of 2011 and 2013, the involvement of urban population in the epidemic was reduced, as well as the morbidity in the people 15-64 years old and schoolchildren 7-14 years old. The duration of the epidemic among the adult population, the mortality rate of the total population, and the mortality rates in all age groups were also decreased. Vice versa, the incidence in the children of preschool age and the elderly people and the duration of the epidemic among children (especially preschool children) were increased. The share of patients 65 years and older, children 0-2 years old, and patients with pathology of the cardiovascular systems among the deceased patients increased to 33.6%.

[Detection of conservative and variable epitopes of the pandemic influenza virus A(H1N1)pdm09 hemagglutinin using monoclonal antibodies]

The goal of this work was to analyze the antigenic structure of the hemagglutinin (HA) of the pandemic influenza virus A(H1N1)pdm09 using monoclonal antibodies (MAbs) and to develop a sandwich ELISA for identification of pandemic strains. Competitive ELISA demonstrated that 6 MAbs against HA of the pandemic influenza A/ IIV-Moscow/01/2009 (H1N1)pdm09 virus identified six epitopes. Binding of MAbs with 22 strains circulating in Russian Federation during 2009-2012 was analyzed in the hemagglutination-inhibition test (HI). The MAbs differed considerably in their ability to decrease the HI activity of these strains. MAb 5F7 identified all examined strains; MAbs 3A3 and 10G2 reacted with the majority of them. A highly sensitive sandwich ELISA was constructed based on these three MAbs that can differentiate the pandemic influenza strains from the seasonal influenza virus. The constancy of the HA epitope that reacts with MAb 5F7 provides its use for identification of the pandemic influenza strains in HI test. MAbs 3D9, 6A3 and 1E7 are directed against the variable HA epitopes, being sensitive to several amino acid changes in Sa, Sb, and Ca2 antigenic sites and in receptor binding site. These MAbs can be used to detect differences in HA structure and to study the antigenic drift of the pandemic influenza virus A(H1N1)pdm09.

[The peculiarities of the influenza epidemics in some areas of Russia during 2012-2013 season. The influenza A (H1N1) pdm09 virus domination in European countries]

The peculiarities of the influenza viruses circulation in 2012-2013 are discussed. The results were obtained in 10 cities of Russia, where basic laboratories of the Influenza Ecology and Epidemics Center of on the basis of Ivanovsky Institute of Virology, Ministry of Health of the Russian Federation, are situated. The increasing rate of the ARD morbidity caused by influenza viruses was observed in January-March 2013. The highest indices of the morbidity were detected during 6-7 weeks with the following decreasing rate till threshold levels to week 14. The influenza A (H1N1) pdm09, A (H3N2), and B viruses were the cause of the epidemic, but their activity differed over areas of Russia. The results of study of the antigenic and genetic properties of the influenza strains demonstrated closed relatives with respect to vaccine strains. In addition, some heterogeneity of the circulating strains and their drift variants were found as well. All tested strains were sensitive to oseltamivir (excluding one A (H1N1) pdm09 strain), zanamivir, arbidol, and remained resistant to rimantadine. The ratio of the ARD viruses was comparable with the last epidemic seasons.

[The 2013-2014 epidemic season. Hospital monitoring and antiviral therapy for influenza ]

AIM

To characterize the 2013-2014 epidemic season from the results of detection of influenza infection in patients; to provide the molecular genetic characteristics of the strains isolated from deceased patients.

SUBJECTS AND METHODS

The investigators examined 1203 patients (387 children, 509 people older than 16 years of age, 307 pregnant women) admitted to Moscow Clinical Infectious Diseases Hospital One with the clinical signs of acute respiratory viral diseases. Nasal lavage and autopsy specimens were used to isolate viral strains, then to sequence genomic fragments, and to determine receptor specificity.

RESULTS

Out of the 1203 examinees, 284 (23.6%) were influenza-positive: 221 (77.8%), 24 (8.5%), and 39 (13.7%) patients had influenza A(H3N2), influenza A(H1N1)pdm09, and influenza B, respectively. Influenza was notified in 42,7% of the pregnant women. There was a preponderance of its moderate form; its severe form developed in single cases having comorbidities. One fatal outcome was registered. The intake of antiviral medications in the first 48 hours of the disease could prevent complications. The investigators revealed mutations in the strain isolated from the bronchoalveolar lavage fluid of a patient with severe pneumonia complicated by acute respiratory distress syndrome.

CONCLUSION

There is evidence that there are mutant A(H1N1)pdm09 viruses that have high pneumotropicity. The high risk of their circulation in the population and the risk of severe influenza forms involving the lower respiratory tract remain. Early antiviral therapy in the first 36-48 hours diminishes the clinical manifestations of influenza and reduces the risk of developing complications.

[Etiology of fatal pneumonia caused by influenza A(H1N1)pdm2009 virus during the pandemic in Russia]

The results of the study of the autopsy materials from 61 patients with the diagnosis of pneumonia received by virological and genetic methods are reviewed. The materials were studied at the Influenza Etiology and Epidemiology Center of the Ivanovsky Institute of Virology, Ministry of Health and Social Development of the Russian Federation, during epidemic seasons 2009-2010 and 2010-2011. The data were analyzed with respect to age, sex, comorbidity diseases and identified on the groups of the risk of severe forms of the disease. The presence of the pandemic influenza virus strain RNA was confirmed in 70.5% of materials; RNA of influenza B was detected in 1.2% cases. The co-infections caused by the bocavirus, adenovirus, parainfluenza virus type 2 and 4, rhinovirus, and streptococcus were detected only in 19.7%. In most cases, the influenza virus was the etiologic agent of lethal pneumonia, which justifies the necessity of the early etiological diagnosis and treatment with antiviral drugs.

[Efficiency of the influenza A and B viruses isolation from nasopharyngeal swabs taken in the test tubes Sigma-Virocult (M40 Compliant, Sigma Virocult) and Virocult (M40 Compliant, Virocult) in 2010-2011 epidemic season]

The goal of this work was to compare the efficiency of the influenza A and B viruses Isolated during 2010-2011 epidemic season. The clinical samples were taken in the test tubes with the transport medium on the.basis of the medium EMEM and commercial test tubes Sigma-Virocult (M40 Compliant, Sigma Virocult) and Virocult (M40 Compliant, Virocult). The results of this work demonstrated higher efficiency of influenza A and B viruses isolation from nasopharyngeal swabs of the patients taken in the test tubes Sigma-Virocult (M40 Compliant, Sigma Virocult) and Virocult (M40 Compliant, Virocult) with the transport medium as compared with the efficiency of influenza strains isolation from nasopharyngeal swabs taken in test tubes with the medium EMEM with respect to all estimated indicators: efficiency of isolation, a passage of isolation and the titer of isolates. The possibility of the long-term storage of a clinical material at room temperature and at 4 degrees C was confirmed, without resorting to freezing, which is significant in the absence of the necessary equipment.

[Development of the influenza epidemic in season 2011-2012 in some areas of Russia: results of activity of the Influenza Etiology and Epidemiology Center of the Ivanovsky Institute of Virology]

The results of analysis of the peculiarities of the epidemic 2011-2012 development in the areas of 10 cities of Russia obtained by basic laboratories of IEES on the base of D.I. Ivanovsky Research Institute of Virology, Ministry of Public Health and Social Development of Russia, are presented. The increasing ARD morbidity caused by the influenza viruses was detected rather late--in February-March 2012. The highest indices of the morbidity were detected during weeks 10-13 followed by decreasing to threshold levels by week 27. Children 0-2 and 3-6 years old were involved the most, meantime the high rate of hospitalization was found for 15-64 years old aged group (25%). Influenza A(H3N2) and B viruses were the cause of the epidemic. The results of studies of the antigenic and genetic properties of the influenza strains showed most of them to be close relatives to the vaccine strains. Some heterogeneity of circulating strains and their drift variants were found as well. All tested strains were sensitive to arbidol, oseltamivir and zanamivir, and saved resistance to rimantadine. The ratio of ARD viruses was comparable with the last epidemic seasons.

[Efficacy of anti-neuraminidase drugs application during and after an influenza pandemic]

The emergent 2009 A(H1N1) pandemic brought into acute focus the problem of choosing the most effective anti-influenza drugs for successive influenza infection spreading control. Oseltamivir and zanamivir, influenza virus neuraminidase inhibitors (NAIs), were recommended by the WHO experts for the treatment and prevention of influenza, including that caused by pandemic strains. A major concern regarding the use of specific antiviral compounds is the emergence of the drug-resistant strains. Oseltamivir carboxylate and zanamivir IC50 values were equal to 0.3-5.2 microM for the most of A(H1N1)pdm09 pandemic strains and 1.6-8.6 microM for the strains of influenza B virus in cell-based ELISA assay (2009-2010 season). All the studied strains of influenza A(H1N1 ) pdm09 (151) and B (22) viruses were sensitive to NAIs (2009-2011 seasons). For the first time in Russia oseltamivir-resistant A(H1N1) pdm09 influenza virus was isolated from the patient on the 5th day of a treatment course of this drug.

[Interaction of influenza A and B viruses with nanodiamond-based sorbents]

The paper presents data on the sorption of influenza A(H1N1), A(H1N1)v, A(H3N2) viruses, cDNA of A(H1N1)v and B viruses on nanodiamonds and furnace charge. The sorption of viruses occurred in different solutions at 4-37 degrees C during 10-20 min. The rate of sorption varied with the concentration of a sorbent in the solution and its structure, but did not with the antigenic formula of viruses or temperature. The sorption capacity of furnace charge towards influenza A and B viruses was higher than that of nanodiamonds. Nonviral proteins (bovine serum albumin and influenza virus antibodies) were found to be bound by both sorbents. Viral desorption did not take place in physiological solution at 4 and 22 degrees C for 48 hours.

[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.

[The specific features of the cocirculation of influenza viruses in the 2010-2011 postpandemic period according to the results of activities of the D. I. Ivanovsky Research Institute of Virology, Ministry of Health and Social Development of Russia]

The paper gives the results of monitoring the circulation of influenza viruses in the 2010-2011 season, that covers the second year of circulation of pandemic A(H1N1)v virus strains, and their interaction with seasonal A (H3N2) and B strains. Unlike the previous season, the beginning of an increase in morbidity was recorded in January 2011; its peak in the most of contiguous areas was noted at 5-7 weeks of 2011, with its further decline to threshold levels at week 11 of 2011. Preschool and school children were most involved in the epidemic process. Three influenza virus strains (A(H1N1)v, A(H3N2), and B) were found to circulate. Differences were found in the level of participation of the isolated strains in individual areas of the Russian Federation. Detailed typing of the isolated strains determined the compliance of the vast majority of them with vaccine viruses. The pandemic influenza A(H1N1)v virus strains retained their susceptibility to oseltamivir and were resistant to rimantadine. The participation of non-influenza acute respiratory viral infection pathogens was estimated as follows: 11.9% for parainfluenza viruses, 5.9% for adenoviruses, and 3.5% for PC viruses, and 0.7% for pneumonia Mycoplasma, which was comparable with the previous epidemic seasons.

[Evaluation of the efficiency of differential diagnosis of influenza by multiplex real-time polymerase chain reaction]

The paper gives the results of a comparative analysis of the detection of influenza viruses in clinical samples, by using multiplex real-time polymerase chain reaction (RT-PCR) and by virus isolation in MDCK cell cultures. The investigation employed 267 nasopharyngeal swab specimens obtained from patients with influenza symptoms during two epidemic seasons (2008-2009 and 2009-2010). Influenza viruses were found in 104 samples (48 with influenza A virus (IAV) and 56 with influenza B virus (IBV)) by multiplex RT-RCR and in 84 samples (35 with IAV and 49 with IBV) by a cultural technique. The results of detection of influenza viruses by the two methods showed 89.4% agreement. The diagnostic sensitivity of multiplex RT-PCR testing a panel of the clinical samples in question was estimated to be 94.3% for IAV and 95.9% for IBV. The diagnostic sensitivity of multiplex RT-PCR in virus detection was demonstrated to be not only highly competitive with virus isolation, but also superior to the latter.

[Viral sorption on polyaniline, carbon nanotubes and their based nanocomposites]

The paper gives data on the sorption of influenza virus pandemic strain A/IIV-Moscow/01/2009 (H1N1)swl, avian influenza viruses with A/H5 and A/H7 hemagglutinin, poliomyelitis virus, and T4-D bacteriophage on polyaniline sorbents, carbon nanotubes, and their based nanocomposites. The sorption of viruses occurred in different solutions at 4-37 degrees C during 15 min or more. The rate of viral sorption depended on the structure of sorbents.

[Monoclonal antibodies with high virus-neutralizing activity against pandemic influenza virus A/llV-Moscow/01/2009 (H1N1)swl]

The authors have obtained a panel of 7 monoclonal antibodies (MAbs) against pandemic influenza virus A/IIV-Moscow/01/2009 (HIN1)swl isolated in Russia. One MAb is directed to a NP protein linear epitope and interacts with all the influenza A viruses under study. Six other MAbs are directed to H1 hemagglutinin conformation-dependent determinants and detect homologous virus in the hemagglutination-inhibition test, enzyme immunoassay, immunofluorescence and virus neutralization tests. MAbs differentiate pandemic influenza viruses A(H1N1)swl from seasonal influenza A(H1N1), A(H3N2), and B viruses. The high neutralizing activity of MAbs permits their use to study the fine antigen structure of influenza virus hemagglutinin and to differentiate the A(H1N1) pandemic influenza viruses and offers promise for obtaining humanized antibodies in order to make specific prevention and treatment of influenza.

[New adamantane derivatives and ways of overcoming the resistance of influenza A viruses to rimantadine and amantadine]

The amino acid and peptide derivatives of 1-adamantane carboxylic acid and rimantadine (18 compounds) have been first synthesized and investigated for their activity against influenza A virus (H1N1, H1N1v). In a series of obtained adamantine derivatives, some compounds have been found to be able to inhibit rimantadine-resistant influenza A virus strains. Thus, the antiviral properties of rimantadine can be restored.

[Taxonomic structure of Orthomyxoviridae: current views and immediate prospects]

Analysis of taxonomic structure of Orthomyxoviridae was undertaken in view of its anticipated evolution. Four concepts of circulation of influenza A viruses in the biosphere are discussed, viz. anthrponose, zooanthroponose, metastrongilose, and protozoan. All of them may be considered in the framework of the general zooantroponose concept. Influenza B and C viruses can not be regarded as strictly anthroponose. Comparative molecular-genetic analysis of the genus Thogotovirus provides a basis for the designation of Thogoto and Batken-Dhori as independent geni. It is speculated that t he proof of transmission of Isaviruses by copepods Caligus elongates and Lepeophtheirus salmonis (Crustacea: Copepoda) may open up a new line of developments in arborvirology since crustacean vectors of viruses have never been described before.

[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.

[Information of the Center for Ecology and Epidemiology of Influenza, D. I. Ivanovsky Research Institute of Virology, Russian Academy of Medical Sciences, on the results of the 2009-2010 influenza and acute respiratory viral infection epidemic season (at week 40 of 2009 to week 22 of 2010) in the world and Russia]

The paper describes the specific features of the 2009-2010 epidemic season in Russia and the world, which are due to the wide spread of a new pandemic strain of influenza A(H1N1)v virus. There is an unusual early upsurge in the incidence of influenza and acute respiratory viral infection (ARVI) (in October-November 2009) with its peak at weeks 45 to 48 of the year with a succeeding reduction to the seasonal values by its end. The circulation of influenza B virus strains was recorded in February-April 2010, which was responsible for the higher epidemic thresholds of morbidity in a number of Russia's regions. A study of the antigenic properties of the strains defined their relationship to the reference strains A/California/07/2009 (H1N1)v and B/Brisbene/60/2008. There were strains with amino acid substitutions at position 222 of hemagglutinin in the population of pandemic influenza A(H1N1)v virus. The strains of the new pandemic influenza A(H1N1)v virus were resistant to remantadine and susceptible to oseltamivir, zanamivir, and arbidol. The influenza B virus strains were susceptible to oseltamivir, zanamivir, and arbidol. The proportion of pathogens of some ARVIs was as follows: parainfluenza viruses, 9.8%; adenoviruses, 5.5%; respiratory syncytial virus, 4.8%; and Mycoplasma pneumonia, 0.6%. There is evidence that there is a need for further monitoring of influenza viruses in Russia.

[Etiotropic therapy of influenza: lessons from the last pandemic]

Analysis of the experience gained during the last pandemic of 'swine' influenza A (H1N1) sw1 is presented with reference to clinical studies and etiotropic therapy. The mechanism of development of severe pneumonia as a result of mutations at the binding site of hemagglutinin receptor enhancing a2'-3'-sialoside specificity and pneumotropism of the virus is described. The data on the efficiency of Ingavirin, a new Russian antiviral for the treatment of influenza, are reported.

[Contribution of D I Ivanovsky Research Institute of Virology to monitoring influenza viruses during epidemics and 2009 pandemic in Russia]

The data on monitoring influenza viruses in Russia are presented based on the research underway at Ivanovsky Research Institute of Virology since 1959. The Institute's priority in isolation and identification of influenza viruses during epidemics and 2009 pandemic is confirmed. Results of assessment of influenza vaccines and etiotropic preparations, development and introduction of new methods for diagnostics of influenza are discussed.

[Pandemic influenza in Russia: specific features of clinical course and the absence of early etiotropic therapy as a risk factor of severe forms of the disease]

AIM

To assess efficacy and safety of ingavirin in the treatment of the flu caused by pandemic virus of flu A (H1N1) sw1 in hospitalized patients compared with oseltamivir.

MATERIAL AND METHODS

A population-based comparative multicenter trial included 194 patients with verified diagnosis of the flu aged 18-60 years with marked clinical symptoms, body temperature over 38 degrees C and duration of the disease 48 hours maximum. The patients were randomized into 2 groups: group 1 (n=152) received ingavirin (90 mg once a day), group 2 received oseltamivir (n=42) in a dose 150 mg twice a day. Duration of the course was 5 days.

RESULTS

Ingavirin and oseltamivir normalized body temperature within treatment hours 24-36 if therapy was initiated in the first disease hours 27.0 +/- 10.0 and 31.9 +/- 10.4. Mean duration of the fever for ingavirin was 35.1 +/- 14.5 hours, for oseltamivir--26.3 +/- 13.0 hours (p < 0.817). The antiviral medicines significantly reduced duration of intoxication (head ache, weakness), catarrhal symptoms (cough, tracheitis, rhinitis), rate of complication vs. patients untreated with antivirus drugs (n=30).

CONCLUSION

The results of the treatment show safety and efficacy of ingavirin in uncomplicated flu caused by pandemic virus of flu A (H1N1) sw1 in inpatients. Early etiotropic therapy is a basic treatment policy able to reduce the number of severe complications and lethality.

[Sensitivity of the epidemic and pandemic influenza virus strains to zanamivir (Relenze) in in vitro experiments]

The paper presents the results of the first Russian experience in evaluating the sensitivity of the epidemic and pandemic influenza virus strains, circulating in the period 2009-2010, to the anti-neuraminidase drug zanamivir. A complex of studies, including enzyme immunoassay, fluorometric assay and partial sequence of the neuraminidases (NA1 and NA2) from influenza A virus strain, was applied. The findings Indicate that all the test strains, including those resistant to oseltamivir, were susceptible to zanamivir. The latter is recommended by the WHO for the prevention and treatment of influenza in pregnant women.

[Molecular genetic studies of the susceptibility of epidemic influenza A(H1N1) virus strains isolated in the 2006-2009 seasons in Russia to oseltamivir (Tamiflu)]

Oseltamivir (Tamiflu) is recommended by WHO experts as a drug to treat and prevent of influenza and to create stocks if its new pandemic variant occurs. The susceptibility of influenza viruses to oseltamivir was studied by polymerase chain reaction-based techniques detecting specific mutations in the neuraminidase gene. The increase in the number of oseltamivir-resistant influenza viruses, isolated from the Russian Federation, with type 1 neuraminidase H274Y mutation from 49% (2007-20008) to 92% (2008-2009) did not depend on the frequency of oseltamivir use. Full correlation of the results obtained by various techniques allows them to be used to monitor the susceptibility of influenza viruses to oseltamivir.

[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.

[Trends in the spread of pandemic influenza A(H1N1) swl in the Far East in 2009]

The paper describes the trend in the spread of pandemic influenza A(H1N1) swl virus in the Far East, which started in this region 2-3 months later than that in the European part of Russia. By mid-October seasonal epidemic influenza was practically displaced by pandemic one.

[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.

[Spread of new pandemic influenza A(H1N1)v virus in Russia]

The paper presents the results of the investigations of the development of a influenza A(H1N1)v pandemic, conducted by the D. I. Ivanovsky Research Institute of Virology, Russian Academy of Medical Sciences, and collaborating laboratories in the European part of Russia, in the Urals, Siberia, and in the Far East. In the prepandemic period (April 27 - June 11, 2009) its first diagnosis was established on May 21, 2009; the first strain was isolated on May 24, 2009; the data on complete genome sequencing were sent to the GenBank; the sensitivity of the strain to commercial antiviral commercial agents was studied. In the early pandemic period (June 11 - August 15), 73 patients who had come from 14 countries of Europe, America, and Asia were identified; 19 virus strains (partially or completely sequenced) were isolated. The pandemic period (August 15 - December 1) was marked by absolute dominance of pandemic influenza virus virtually in the absence of seasonal influenza; the first death caused by pandemic influenza was detected in late August; 3053 subjects were infected with the pandemic strain, as shown by polymerase chain reaction diagnosis; 202 strains were identified.

[The 24 May, 2009 isolation of the first A/IIV-Moscow/01/2009 (H1N1)swl strain similar to swine A(H1N1) influenza virus from the first Moscow case detected on May 21, 2009, and its deposit in the state collection of viruses (SCV No. 2452 dated May 24, 2009)]

The paper presents the results of the first isolation of the new influenza virus in Moscow and the Russian Federation, which was similar to the swine A/IIV-Moscow/01/2009(H1N1)swl strain isolated on May 24, 2009 from a Russian arrived in Moscow from the USA on May 19, 2009. The antigenic, biological, and molecular genetic properties of this virus were studied. The virus was isolated on MDCK and chick embryos, the hemagglutination titers being 1:8-1:16 AE; the infectious titers being 6.51g of the tissue cytopathogenic infective dose (TCID50) and 7.01g of the common infective dose (CID50). The virus was sensitive to arbidol, ribavirin, oseltamivir, and resistant to rimantadine. The complete virus genome was sequenced; the data were accepted to the Gen Bank on May 28, 2009 under GQ219584-GQ219590 and GQ202724. The significant gene substitution of neuraminidase Asp for Gly in position 451, which has been undetectable in any other strain published in the Gen Bank by the present time is unique only to A/IIV-Moscow/01/2009 (H1N1)swl. The virus has been deposited in the State Collection of Viruses, D. I. Ivanovsky Institute of Virology, Russian Academy of Medical Sciences, under No. 2452 dated May 24, 2009.

[The characteristics of epidemic influenza A and B virus strains circulating in Russia during the 2007-2008 season]

In 2007-2008 in Russia, the epidemic upsurge of influenza morbidity was caused by the active circulation of influenza A(H1N1, A(H3N2), and B viruses. The center for Ecology and Epidemiology of Influenza studied 334 epidemic strains. The results of a comparative study of the svirus specificity of commercial test systems (AmpliSens Influenza virus A/B and AmpliSens Influenza virus A/H5N1) for the polymerase chain reaction diagnosis and virological assays, including virus isolation, revealed their high correlation, which confirms that they may be expensively used to monitor the circulation of influenza viruses in the Russian Federation. All the strains were isolated in the MDCK cell culture. Influenza A(H1N1) viruses (n = 127) were antigenic variants of the reference strains A/Solomon Islands/3/06 and A/Brisbane/59107. Influenza A(H3N2) viruses (n = 49) were antigenic variants of the reference strains A/Wisconsin/67/05 and A/Brisbane/10/08. One hundred and fifty seven Influenza B strains were drift variants of the reference strains B/Florida/4/06 and B/Shanghai/361/02 of lineage B/Yamagata/16/88 and one strain, a variant of Malaysia/2506/04 related to lineage B/victoria/2/87. The isolates interacted actively with human 0(I) blood group erythrocytes and much more weakly with chicken ones. All study influenza A(H1N1) viruses (n = 74) preserved their sensitivity to rimantadine while 24 (77%) of the 31 study influenza A(H3N2) virus strains were resistant. A study of the time course of changes in the generation of antibodies in the donor sera obtained in Moscow and the Moscow Region in different periods of the epidemic process revealed an increase in antibodies to the reference influenza A and B virus strains circulating in this period.

[Monitoring of the sensitivity of epidemic influenza virus strains isolated in Russia to etiotropic chemical agents]

The paper presents the results of studying the spectrum of influenza A and B viruses to rimantadine, arbidol, and oseltamivir and describes the methods used for these purposes for epidemiological surveillance. Different sensitivities to rimantadine were found among influenza A viruses. During the 2007-2008 season, the vast majority of influenza A(H3N2) virus strains were resistant to rimantadine (77%) while all influenza A(H1N1) virus strains preserved their resistance to this drug. The fact that the epidemic influenza A(H1N1) virus strains that carry the mutation responsible for resistance to the neuraminidase inhibitor oseltamivir (Tamiflu) circulated in the Russian Federation was first established. At the same time all the study influenza A(H1N1) virus strains preserved their susceptibility to rimantadine. The sensitivity of the epidemic strains to arbidol has been confirmed.

[Efficacy of ingavirin in adults with influenza]

AIM

To compare therapeutic efficacy and safety of ingavirin and arbidol in patients with influenza.

MATERIAL AND METHODS

The trial included 105 patients with a verified diagnosis of influenza, definite clinical symptoms, body temperature at least 38 degrees C and duration of the disease 36 hours maximum. Ingavirin efficacy was analysed basing on the evidence for 100 patients with uncomplicated influenza. The patients were randomized into three groups: taking ingavirin in a single daily dose 90 mg (n = 33), placebo (n = 36) or arbidol (200 mg 4 times a day). The duration of the treatment was 5 days.

RESULTS

Intake of ingavirin in initial 24-36 hours of the disease significantly reduced fever compared to placebo and arbidol (34.5, 72.0 and 48.4 hours, respectively). Ingavirin was less toxic and had no side effects.

CONCLUSION

Ingavirin is safe and effective in the treatment of influenza. By some criteria it is more effective than arbidol.

[Viferon efficacy in influenza in adult patients]

The therapeutic efficacy of Viferon (suppositories of human recombinant interferon alfa-2) was investigated in a double-blind controlled study with the use of Arbidol as a reference drug in the treatment of patients with influenza. Viferon and Arbidol lowered the signs of the fever, intoxication, catarrh and the disease as the whole.