Imported cases of dengue fever in Russia during 2010-2013.

OBJECTIVE: To confirm dengue infection among Russian tourists returned from Southeast and Mexico in 2010-2013 with clinical signs of infection. METHODS: Blood and serum samples from patients were collected. NS1 antigen and human IgM/IgG antibodies to dengue virus were identified using commercial tests manufactured by "Standard Diagnostics, INC.", Korea. ELISA test was used for the quantitative analyses of human IgM/IgG antibodies to dengue virus ("Orgenics Ltd.", Israel). Viral RNA was detected using commercial real-time PCR tests manufactured by "Genome Diagnostics Pvt. Ltd.", India and "Vector", Russia. Genotypes of revealed dengue viruses were determined employing nucleotide sequencing and phylogenetic analysis of 5'-UTR of the viral genome. RESULTS: A total of 98 collected blood samples were analyzed. Fifty samples were positive for at least one of four markers of dengue infection. IgM to dengue virus were revealed in 38 samples, in 25 samples IgM were combined with IgG. NS1 antigen was detected in 43 samples. 22 serum samples were positive for dengue virus RNA. The majority of samples (12 patients) from tourists returned from Thailand were positive for genotype 1 of dengue virus, 2nd and 4th genotype were identified each in 1 patient. CONCLUSIONS: Due to laboratory confirmed cases of imported dengue fever in Russia, the differential diagnosis of dengue is strictly recommended for tourists returning from endemic areas.

[Etiological structure of acute respiratory viral infections morbidity in Novosibirsk and Novosibirsk region in epidemic season 2011-2012].

INTRODUCTION: ARI occupying the first place in the structure of total human morbidity. The aim of the study was to investigate the species diversity of the viruses causing AR among residents of the Novosibirsk region during epidemic season (October to April). MATERIALS AND METHODS: 164 nasopharyngeal swabs were collected and analyzed. Viral RNA/DNA, cDNA synthesis and PCR were carried out employing "RIBO-prep" "eReverta-L", "AmpliSens Influenza virus A/B-FL" and "AmpliSens ARI-screen-FL" kits (CRI of Epidemiology). RESULTS: Etiological agent of the disease was found in 69(43%) samples. Monoinfection was found in 58 (35%). In 14 (9%) samples were detected serogroup I coronaviruses, in 13 (8%) rhinoviruses, in 7 (4%) respiratory syncytial virus, in 6 (4%) parainfluenza virus type 1, in 5 (3%) parainfluenza virus type 3. Adenoviruses and bocavirus were identified in 3 (2%) samples. Parainfluenza virus type 2 and 4, metapneumovirus, serogroup Il coronaviruses (HKU1 and OC43) were presented in 2 (1%) samples. In 11 (7%) samples was found mixed infection. CONCLUSION: The majority of common colds were caused by serogroup I coronaviruses (NL63 and 229E), rhinoviruses and mixed infections. The peak of species variability of viruses caused acute respiratory infections was determined in age group of children 2-4 years old. In older age groups the species variability of analyzed viruses was decreased, rhinovirus infection becomes prevalent.

[Development and validation of the real-time PCR assay for the identification of viral agents causing acute respiratory infections in humans].

The real time PCR assay targeting influenza A and B virus, 5 subtypes of influenza A virus (seasonal H1N1, pandemic H1N1 (2009), seasonal H3N2, pathogenic for human subtypes of avian influenza H5 and H7), respiratory syncytial virus, and adenovirus was developed. The analytical sensitivity of the developed assay was 1 x 10(3) genome equivalents per ml. The diagnostic sensitivity of the method was 1 x l0(3)-10(4) viral particles per ml. Experiments with human DNA/cDNA and viral cDNA showed a markedly high diagnostic specificity of the developed PCR assay. In the assay of the developed PCR test, 50 nasopharyngeal swab specimens were tested. The etiology was identified in 33 samples.

Development and verification of real-time PCR assay for identification of viral agents causing acute respiratory infections in human beings.

A multiplex polymerase chain reaction (PCR) for identification of four viruses causing acute respiratory diseases in human beings was developed. The analytical sensitivity of developed RT-PCR for identification of adenovirus, respiratory-syncytial virus, flu viruses types A and B, and actual subtypes of type A flu virus (seasonal and pandemic variants H1N1, seasonal H3N2, and viruses of bird flu that are pathogenic to human beings H5 and H7) was 1 × 103 genome equivalents per milliliter. Diagnostic sensitivity for flu virus type A and B, and also subtypes H1 (seasonal H1N1, pandemic variant of H1N1 of year 2009), H3, H5 was 1 × 103-104 viral particles per milliliter. The method developed has high specificity and does not have positive signal in experiments with DNA/cDNA of human beings and viral DNA. We have studied 50 samples using the developed set. Etiology was defined in 33 samples.

[Genetic variability of isolates of pandemic influenza A virus H1N1 isolated in Russia in 2009].

Complete nucleotide sequence of the genome segments encoding the surface glycoproteins, hemagglutinin, and neuraminidase of influenza A virus H1N1 derived from the patients with influenza in the context of pandemic (H1N1) 2009 was determined out of 14 isolates of pandemic influenza. The philogenetic analysis of these sequences demonstrated their genetic similarity to the corresponding genes of the pandemic influenza virus A (H1N1) 2009 isolates obtained in other countries; each gene homology was greater than 99%. Neuraminidase mutations causing virus resistance to oseltamivir and other neuraminidase inhibitors, known from the literature, were not detected. The hemagglutinin gene mutation D222G was found in 4 isolates from autopsy material. In the hemagglutinin of pandemic A/Salekhard/01/2009(H1N1) isolate a mutation G155E leading to the increase in viral replication in developing chick embryos was detected. The nature and frequency of nucleotides substitutions within HA and NA genes were determined in the current research.

[Clinical testing of hygienic criteria for assessing working conditions]. / Klinicheskaia aprobatsiia gigienicheskikh kriteriev otsenki uslovii truda.

Occupational morbidity in railway transport is discussed. The rates of occupational morbidity are compared with that due to temporary working incapacity. There were no direct correlations between the incidence of major nosological entities of occupational diseases, the magnitude and rate of influence of industrial factors, which provides evidence for their further testing and correction.