ABSTRACT
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.
ABSTRACT
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.
Subject(s)
Influenza A Virus, H1N1 Subtype/isolation & purification , Influenza A Virus, H3N2 Subtype/isolation & purification , Influenza, Human/diagnosis , Real-Time Polymerase Chain Reaction/methods , Respiratory Tract Infections/diagnosis , Animals , Birds/virology , Humans , Influenza A Virus, H1N1 Subtype/genetics , Influenza A Virus, H3N2 Subtype/genetics , Influenza A Virus, H5N1 Subtype/genetics , Influenza A Virus, H5N1 Subtype/isolation & purification , Influenza B virus/genetics , Influenza B virus/isolation & purification , Influenza in Birds/diagnosis , Influenza in Birds/virology , Influenza, Human/virology , Respiratory Tract Infections/genetics , Respiratory Tract Infections/virologyABSTRACT
AIM: Studies of cultural, virologic, antigenic properties of 89 samples of pandemic influenza A(H1N1) 2009 virus isolated in Russian Federation from May 2009 to March 2010. MATERIALS AND METHODS: Properties of isolated samples were compared with those of the reference strain A/ California/04/2009 (H1N1). RESULTS: Studies of biological properties and analysis of genome nucleotide sequences of the isolated samples showed that those strains are closely related to the reference strain. CONCLUSION: Monitoring of genetic, virologic and antigenic properties of pandemic influenza A(H1N1) 2009 virus isolates carried out from May 2009 to March 2010 did not reveal significant changes in the abovementioned properties of the virus or emergence of mutations that can lead to such changes.
Subject(s)
Influenza A Virus, H1N1 Subtype/genetics , Influenza, Human/epidemiology , Influenza, Human/virology , Pandemics , Animals , Antibodies, Viral/analysis , Birds/virology , Humans , Influenza A Virus, H1N1 Subtype/classification , Influenza A Virus, H1N1 Subtype/immunology , Mice , Mutation , Russia/epidemiology , Sequence Analysis, DNAABSTRACT
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.
