scholarly journals Demographic distribution and transmission potential of influenza A and 2009 pandemic influenza A H1N1 in pilgrims

2014 ◽  
Vol 8 (09) ◽  
pp. 1169-1175 ◽  
Author(s):  
Ahmed Ashshi ◽  
Esam Azhar ◽  
Ayman Johargy ◽  
Atif Asghar ◽  
Aiman Momenah ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Influenza A ◽  
World Health ◽  
Influenza A Viruses ◽  
Exact Test ◽  
Transmission Potential ◽  
Control Programs ◽  
Influenza A H1n1 ◽  
H1n1 Strain

Introduction: The World Health Organization’s persistent reporting of global outbreaks of influenza A viruses, including the 2009 pandemic swine A H1N1 strain (H1N1pdm09), justified the targeted surveillance of pilgrims during their annual congregation that pools more than two million people from around 165 nations in a confined area of Makkah city in the Kingdom of Saudi Arabia (KSA). Methodology: A total of 1,600 pilgrims were included in the targeted surveillance of influenza A and the 2009 pandemic swine H1N1 strain in the Hajj (pilgrimage) season of 2010. Each pilgrim responded to a demographic and health questionnaire. Collected oropharyngeal swabs were analyzed by real-time PCR for influenza A viruses, and positive samples were further analyzed for the presence of H1N1pdm09. Fisher’s exact test was applied in the analysis of the significance of the distribution of influenza-positive pilgrims according to demographic characters. Results: A total of 120 pilgrims (7.5%) tested positive for influenza A viruses by real-time PCR. Nine out of the 120 influenza-A-positive pilgrims (7.5%) were positive for H1N1pdm09. Demographics played a significant role in those pilgrims who tested positive for influenza A. Conclusions: The detection of H1N1pdm09 in pilgrims at their port of entry to the KSA was alarming, due to the high potential of trans-boundary transmission. This situation necessitates the implementation of specific prevention and control programs to limit infection by influenza A viruses.

scholarly journals Novel Swine Infl uenza AH1N1 and the Phase Six Pandemic

2010 ◽  
Vol 49 (179) ◽  
Author(s):  
M Khadka
Keyword(s):  
Public Health ◽  
Influenza A ◽  
Swine Influenza ◽  
Antigenic Drift ◽  
World Health ◽  
Health Concern ◽  
Influenza A Viruses ◽  
Influenza A H1n1 ◽  
H1n1 Strain ◽  
Health Organization

The family Orthomyxoviridae consists of Influenza A virus which is negative sense single stranded virus. The genome of the virus is segmented and possesses a peculiar trait of genetic reassortment. The influenza virus on its envelop consists of the antigenic glycoprotein like haemagglutinin (HA) and neuraminidase (NA). The changes in those glycoprotein components due to antigenic shift and antigenic drift leads to the development of new strain of Influenza A viruses. Now the novel swine influenza A/H1N1 strain has been detected from different parts of the world which is causing pandemic. World Health Organization has declared the pandemic phase six and more than 60 countries have reported the cases of novel influenza A/H1N1 strain including Nepal. As the disease is spreading world wide, it is a major public health concern for all the countries. And especially the developing countries like Nepal should immediately respond to the situation and should be well prepared to combat the disease before the disease spreads to enough population. Keywords: pandemic, public health, reassortment, swine influenza A/H1N1.

scholarly journals Evaluation of four real-time PCR assays for detection of influenza A(H1N1)v viruses

2009 ◽  
Vol 14 (22) ◽  
Author(s):  
J Ellis ◽  
M Iturriza ◽  
R Allan ◽  
A Bermingham ◽  
K Brown ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Influenza A ◽  
Influenza Viruses ◽  
Influenza B ◽  
Influenza A Viruses ◽  
Concurrent Use ◽  
Influenza A H1n1 ◽  
Similar Range ◽  
Pcr Assays

The sensitivity and specificity of four real-time PCR assays (HPA A(H1)v, CDC A (H1)v, HPA A(N1)v and NVRL S-OIV assays) was evaluated for detection of influenza A(H1N1)v viruses. Nose and throat swab samples containing influenza A(H1N1)v viruses, seasonal influenza AH3N2, AH1N1, influenza B viruses, or negative for influenza viruses were tested by the four assays. Specificity was also analysed using influenza A viruses of different subtypes and non-related respiratory viruses. The sensitivities and specificities of the four assays were in a similar range and suitable for diagnostic use. The HPA (H1)v and the S-OIV assays were the most sensitive assays for use as a first line test, but the S-OIV assay was less specific, detecting all avian subtypes of influenza A viruses tested. The results of this study demonstrate that the concurrent use of primary diagnostic and confirmatory assays provides rapid and accurate assessment of confirmed cases, and allows appropriate management of patients.

scholarly journals Library of Prefabricated Locked Nucleic Acid Hydrolysis Probes Facilitates Rapid Development of Reverse-Transcription Quantitative Real-Time PCR Assays for Detection of Novel Influenza A/H1N1/09 Virus

2009 ◽  
Vol 55 (12) ◽  
pp. 2218-2222 ◽  
Author(s):  
Jürgen J Wenzel ◽  
Heiko Walch ◽  
Markus Bollwein ◽  
Hans Helmut Niller ◽  
Waltraud Ankenbauer ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Real Time ◽  
Reverse Transcription ◽  
Real Time Pcr ◽  
Influenza A ◽  
Rapid Development ◽  
Locked Nucleic Acid ◽  
Quantitative Real Time Pcr ◽  
Influenza A H1n1 ◽  
Novel Influenza A

Abstract Background: The emergence of a novel pandemic human strain of influenza A (H1N1/09) has clearly demonstrated the need for flexible tools enabling the rapid development of new diagnostic methods. Methods: We designed a set of reverse-transcription quantitative real-time PCR (RT-qPCR) assays based on the Universal ProbeLibrary (UPL)—a collection of 165 presynthesized, fluorescence-labeled locked nucleic acid (LNA) hydrolysis probes—specifically to detect the novel influenza A virus. We evaluated candidate primer/UPL-probe pairs with 28 novel influenza A/H1N1/09 patient samples of European and Mexican origin. Results: Of 14 assays in the hemagglutinin (HA) and neuraminidase (NA) genes, 12 detected viral nucleic acids from diluted patient samples without need for further optimization. We characterized the diagnostic specificity of the 2 best-performing assays with a set of samples comprising various influenza virus strains of human and animal origin that showed no cross-reactivity. The diagnostic sensitivity of these 2 primer/probe combinations was in the range of 100–1000 genomic copies/mL. In comparison to a reference assay recommended by the German health authorities, the analytical sensitivities and specificities of the assays were equivalent. Conclusions: Facing the emergence of novel influenza A/H1N1/09, we were able to develop, within 2 days, a set of sensitive and specific RT-qPCR assays for the laboratory diagnosis of suspected cases. H1N1/09 served as a model to show the feasibility of the UPL approach for the expedited development of new diagnostic assays to detect emerging pathogens.

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