The Experts below are selected from a list of 39 Experts worldwide ranked by ideXlab platform
Jianwei Wang - One of the best experts on this subject based on the ideXlab platform.
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Influenza A/H1N1 2009 pandemic and respiratory Virus infections, Beijing, 2009-2010.
PLoS ONE, 2012Co-Authors: Yaowu Yang, Zhong Wang, Lili Ren, Wei Wang, Guy Vernet, Gláucia Paranhos-baccalà, Qi Jin, Jianwei WangAbstract:To determine the role of the pandemic influenza A/H1N1 2009 (A/H1N1 2009pdm) in acute respiratory tract infections (ARTIs) and its impact on the epidemic of seasonal influenza Viruses and other common respiratory Viruses, nasal and throat swabs taken from 7,776 patients with suspected viral ARTIs from 2006 through 2010 in Beijing, China were screened by real-time PCR for influenza Virus Typing and subTyping and by multiplex or single PCR tests for other common respiratory Viruses. We observed a distinctive dual peak pattern of influenza epidemic during the A/H1N1 2009pdm in Beijing, China, which was formed by the A/H1N1 2009pdm, and a subsequent influenza B epidemic in year 2009/2010. Our analysis also shows a small peak formed by a seasonal H3N2 epidemic prior to the A/H1N1 2009pdm peak. Parallel detection of multiple respiratory Viruses shows that the epidemic of common respiratory Viruses, except human rhinoVirus, was delayed during the pandemic of the A/H1N1 2009pdm. The H1N1 2009pdm mainly caused upper respiratory tract infections in the sampled patients; patients infected with H1N1 2009pdm had a higher percentage of cough than those infected with seasonal influenza or other respiratory Viruses. Our findings indicate that A/H1N1 2009pdm and other respiratory Viruses except human rhinoVirus could interfere with each other during their transmission between human beings. Understanding the mechanisms and effects of such interference is needed for effective control of future influenza epidemics.
Leo L M Poon - One of the best experts on this subject based on the ideXlab platform.
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a six plex droplet digital rt pcr assay for seasonal influenza Virus Typing subTyping and lineage determination
Influenza and Other Respiratory Viruses, 2020Co-Authors: Nathaniel K C Leong, Dennis K M Ip, Benjamin J Cowling, Leo L M PoonAbstract:BACKGROUND There are two influenza A subtypes (H1 and H3) and two influenza B lineages (Victoria and Yamagata) that currently co-circulate in humans. In this study, we report the development of a six-plex droplet digital RT-PCR (ddRT-PCR) assay that can detect HA and M segments of influenza A (H1, H3, and M) and influenza B (Yamagata HA, Victoria HA, and M) Viruses in a single reaction mixture. It can simultaneously detect six different nucleic acid targets in a ddRT-PCR platform. METHODS The six-plex ddRT-PCR used in this study is an amplitude-based multiplex assay. The analytical performance of the assay was evaluated. Correlation with standard qRT-PCR methodology was assessed using 55 clinical samples. RESULTS The assay has a wide dynamic range, and it has good reproducibility within and between runs. The limit of quantification of each target in this assay ranged from 15 copies/reaction for influenza B Victoria M gene to 45 copies/reaction for influenza B Yamagata M gene. In addition, this assay can accurately quantify each of these targets in samples containing viral RNAs from two different Viruses that were mixed in a highly skewed ratio. Typing, subTyping, and lineage differentiation data of 55 tested clinical respiratory specimens were found to be identical to those deduced from standard monoplex qRT-PCR assays. CONCLUSIONS The six-plex ddRT-PCR test was demonstrated to be highly suitable for detecting dual influenza infection cases. This assay is expected to be a useful diagnostic tool for clinical and research use.
Torben Storgaard - One of the best experts on this subject based on the ideXlab platform.
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sensitive detection and Typing of porcine reproductive and respiratory syndrome Virus by rt pcr amplification of whole viral genes
Veterinary Microbiology, 1998Co-Authors: Martin B Oleksiewicz, Anette Botner, K G Madsen, Torben StorgaardAbstract:Following the recent use of a live vaccine against porcine reproductive and respiratory syndrome Virus (PRRSV) in Denmark, both American (vaccine) and European-type PRRSV now coexist in Danish herds. This situation highlighted a requirement for supplementary tests for precise Virus-Typing. As a result, we developed a RT-PCR assay able to detect as well as type PRRSV. To provide maximal sequence information, complete viral open reading frames (ORFs 5 and 7) were targeted for amplification. The RT-PCR test was able to amplify complete PRRSV ORFs from complex materials such as boar semen containing as little as 1 TCID50 ml−1 of PRRSV. Typing of Viruses was accomplished by any one of three strategies: (i) use of type-specific PCR primers, (ii) size determination of ORF 7 amplicons, (iii) DNA sequencing. All three Typing strategies showed complete concordance with the currently used method of Typing with monoclonal antibodies (MAbs) when used on a panel of PRRSV field isolates covering the period 1992–1997. The ORF 7-based test had particularly desirable characteristics, namely, highly sensitive detection of PRRSV without apparent type bias, Typing of the detected Virus, discrimination between pure and mixed Virus populations, and semi-quantitative assessment of type ratios in mixed populations, all in a single PCR reaction. In addition, the obtained sequence data were used to predict two simple and rapid strategies (single-enzyme restriction length polymorphy analysis and oligonucleotide hybridization) for confirmation of the specificity of ORF 7 RT-PCR reactions. As such, the RT-PCR assay provides a new, powerful diagnostic tool to study the population dynamics between present and emerging PRRSV-types.
Yaowu Yang - One of the best experts on this subject based on the ideXlab platform.
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Influenza A/H1N1 2009 pandemic and respiratory Virus infections, Beijing, 2009-2010.
PLoS ONE, 2012Co-Authors: Yaowu Yang, Zhong Wang, Lili Ren, Wei Wang, Guy Vernet, Gláucia Paranhos-baccalà, Qi Jin, Jianwei WangAbstract:To determine the role of the pandemic influenza A/H1N1 2009 (A/H1N1 2009pdm) in acute respiratory tract infections (ARTIs) and its impact on the epidemic of seasonal influenza Viruses and other common respiratory Viruses, nasal and throat swabs taken from 7,776 patients with suspected viral ARTIs from 2006 through 2010 in Beijing, China were screened by real-time PCR for influenza Virus Typing and subTyping and by multiplex or single PCR tests for other common respiratory Viruses. We observed a distinctive dual peak pattern of influenza epidemic during the A/H1N1 2009pdm in Beijing, China, which was formed by the A/H1N1 2009pdm, and a subsequent influenza B epidemic in year 2009/2010. Our analysis also shows a small peak formed by a seasonal H3N2 epidemic prior to the A/H1N1 2009pdm peak. Parallel detection of multiple respiratory Viruses shows that the epidemic of common respiratory Viruses, except human rhinoVirus, was delayed during the pandemic of the A/H1N1 2009pdm. The H1N1 2009pdm mainly caused upper respiratory tract infections in the sampled patients; patients infected with H1N1 2009pdm had a higher percentage of cough than those infected with seasonal influenza or other respiratory Viruses. Our findings indicate that A/H1N1 2009pdm and other respiratory Viruses except human rhinoVirus could interfere with each other during their transmission between human beings. Understanding the mechanisms and effects of such interference is needed for effective control of future influenza epidemics.
Nathaniel K C Leong - One of the best experts on this subject based on the ideXlab platform.
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a six plex droplet digital rt pcr assay for seasonal influenza Virus Typing subTyping and lineage determination
Influenza and Other Respiratory Viruses, 2020Co-Authors: Nathaniel K C Leong, Dennis K M Ip, Benjamin J Cowling, Leo L M PoonAbstract:BACKGROUND There are two influenza A subtypes (H1 and H3) and two influenza B lineages (Victoria and Yamagata) that currently co-circulate in humans. In this study, we report the development of a six-plex droplet digital RT-PCR (ddRT-PCR) assay that can detect HA and M segments of influenza A (H1, H3, and M) and influenza B (Yamagata HA, Victoria HA, and M) Viruses in a single reaction mixture. It can simultaneously detect six different nucleic acid targets in a ddRT-PCR platform. METHODS The six-plex ddRT-PCR used in this study is an amplitude-based multiplex assay. The analytical performance of the assay was evaluated. Correlation with standard qRT-PCR methodology was assessed using 55 clinical samples. RESULTS The assay has a wide dynamic range, and it has good reproducibility within and between runs. The limit of quantification of each target in this assay ranged from 15 copies/reaction for influenza B Victoria M gene to 45 copies/reaction for influenza B Yamagata M gene. In addition, this assay can accurately quantify each of these targets in samples containing viral RNAs from two different Viruses that were mixed in a highly skewed ratio. Typing, subTyping, and lineage differentiation data of 55 tested clinical respiratory specimens were found to be identical to those deduced from standard monoplex qRT-PCR assays. CONCLUSIONS The six-plex ddRT-PCR test was demonstrated to be highly suitable for detecting dual influenza infection cases. This assay is expected to be a useful diagnostic tool for clinical and research use.
