2,422 results match your criteria H1N1 Influenza Swine Flu

Natural Reassortment of Eurasian Avian-Like Swine H1N1 and Avian H9N2 Influenza Viruses in Pigs, China.

Emerg Infect Dis 2022 Jul;28(7):1509-1512

Several zoonotic influenza A viruses detected in humans contain genes derived from avian H9N2 subtypes. We uncovered a Eurasian avian-like H1N1 swine influenza virus with polymerase basic 1 and matrix gene segments derived from the H9N2 subtype, suggesting that H9N2 viruses are infecting pigs and reassorting with swine influenza viruses in China. Read More

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Potential Threats to Human Health from Eurasian Avian-Like Swine Influenza A(H1N1) Virus and Its Reassortants.

Emerg Infect Dis 2022 Jul 9;28(7):1489-1493. Epub 2022 Jun 9.

During 2018-2020, we isolated 32 Eurasian avian-like swine influenza A(H1N1) viruses and their reassortant viruses from pigs in China. Genomic testing identified a novel reassortant H3N1 virus, which emerged in late 2020. Derived from G4 Eurasian H1N1 and H3N2 swine influenza viruses. Read More

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Development of amperometric biosensor based on cloned hemagglutinin gene of H1N1 (swine flu) virus.

3 Biotech 2022 Jun 1;12(6):141. Epub 2022 Jun 1.

Centre for Medical Biotechnology, Maharshi Dayanand University, Rohtak, Haryana 124007 India.

The recent emergence of respiratory viruses especially COVID-19 and swine flu has underscored the need for robust and bedside detection methods. Swine flu virus is a very infectious virus of the respiratory system. Timely detection of this virus with high specificity and sensitivity is crucial for reducing morbidity as well as mortality. Read More

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Possible bidirectional human-swine and subsequent human-human transmission of influenza virus A(H1N1)/2009 in Japan.

Zoonoses Public Health 2022 May 10. Epub 2022 May 10.

Avian Zoonosis Research Center, Faculty of Agriculture, Tottori University, Tottori, Japan.

In 2019, sows at a swine farm in Japan showed influenza-like illness (ILI) shortly after contact with an employee that exhibited ILI. Subsequently, a veterinarian became sick shortly after examining the sows and was diagnosed with influenza A virus (IAV) infection. Then, her family also contracted the infection. Read More

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Pathogenesis and transmission of human seasonal and swine-origin A(H1) influenza viruses in the ferret model.

Emerg Microbes Infect 2022 Dec;11(1):1452-1459

Centers for Disease Control and Prevention, Influenza Division, National Center for Immunization and Respiratory Diseases, Atlanta, GA, USA.

Influenza A viruses (IAVs) in the swine reservoir constantly evolve, resulting in expanding genetic and antigenic diversity of strains that occasionally cause infections in humans and pose a threat of emerging as a strain capable of human-to-human transmission. For these reasons, there is an ongoing need for surveillance and characterization of newly emerging strains to aid pandemic preparedness efforts, particularly for the selection of candidate vaccine viruses and conducting risk assessments. Here, we performed a parallel comparison of the pathogenesis and transmission of genetically and antigenically diverse swine-origin A(H1N1) variant (v) and A(H1N2)v, and human seasonal A(H1N1)pdm09 IAVs using the ferret model. Read More

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December 2022

Serological Surveillance of the H1N1 and H3N2 Swine Influenza A Virus in Chinese Swine between 2016 and 2021.

Biomed Res Int 2022 28;2022:5833769. Epub 2022 Apr 28.

Department of Fundamental Veterinary Medicine, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, 61 Daizong Street, Tai'an 271018, China.

Background: Swine influenza A virus (IAV-S) is a common cause of respiratory disease in pigs and poses a major public health threat. However, little attention and funding have been given to such studies. The aim of this study was to assess the prevalence of the Eurasian avian-like H1N1 (EA H1N1), 2009 pandemic H1N1 (pdm/09 H1N1), and H3N2 subtype antibodies in unvaccinated swine populations through serological investigations. Read More

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Determining Existing Human Population Immunity as Part of Assessing Influenza Pandemic Risk.

Emerg Infect Dis 2022 05;28(5):977-985

Zoonotic influenza infections continue to threaten human health. Ongoing surveillance and risk assessment of animal viruses are needed for pandemic preparedness, and population immunity is an important component of risk assessment. We determined age-stratified hemagglutinin inhibition seroprevalence against 5 swine influenza viruses circulating in Hong Kong and Guangzhou in China. Read More

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Evidence of influenza A infection and risk of transmission between pigs and farmworkers.

Zoonoses Public Health 2022 Apr 20. Epub 2022 Apr 20.

Veterinary Population Medicine Department, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, USA.

Interspecies transmission of influenza A virus (IAV) between pigs and people represents a threat to both animal and public health. To better understand the risks of influenza transmission at the human-animal interface, we evaluated 1) the rate of IAV detection in swine farmworkers before and after work during two human influenza seasons, 2) assessed risk factors associated with IAV detection in farmworkers and 3) characterized the genetic sequences of IAV detected in both workers and pigs. Of 58 workers providing nasal passage samples during 8-week periods during the 2017/18 and 2018/19 influenza seasons, 33 (57%) tested positive by rRT-PCR at least once. Read More

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Human infection with a reassortant swine-origin influenza A(H1N2)v virus in Taiwan, 2021.

Virol J 2022 04 7;19(1):63. Epub 2022 Apr 7.

Center for Diagnostics and Vaccine Development, Centers for Disease Control, No. 161, Kun-Yang Street, Taipei, 11561, Taiwan, ROC.

Background: Influenza A virus infections occur in different species, causing mild-to-severe symptoms that lead to a heavy disease burden. H1N1, H1N2 and H3N2 are major subtypes of swine influenza A viruses in pigs and occasionally infect humans.

Methods: A case infected by novel influenza virus was found through laboratory surveillance system for influenza viruses. Read More

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Report of the National Influenza Surveillance Scheme, 2011 to 2018.


Commun Dis Intell (2018) 2022 Mar 28;46. Epub 2022 Mar 28.

Office of Health Protection and Response, Australian Government Department of Health.

Abstract: This report describes influenza surveillance activities in Australia for the period 2011 to 2018. Data were extracted from several sources constituting the National Influenza Surveillance Scheme (NISS). Laboratory-confirmed influenza notification rates (per 100,000 population) increased from 122 in 2011 to 1,021 in 2017, before declining to 235 in 2018. Read More

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Host and geographic barriers shape the competition, coexistence, and extinction patterns of influenza A (H1N1) viruses.

Ecol Evol 2022 Mar 21;12(3):e8732. Epub 2022 Mar 21.

State Key Laboratory of Integrated Management on Pest Insects and Rodents in Agriculture Institute of Zoology Chinese Academy of Sciences Beijing China.

The influenza virus mutates and spreads rapidly, making it suitable for studying evolutionary and ecological processes. The ecological factors and processes by which different lineages of influenza compete or coexist within hosts through time and across geographical space are poorly known. We hypothesized that competition would be stronger for influenza viruses infecting the same host compared to different hosts (the Host Barrier Hypothesis), and for those with a higher cross-region transmission intensity (the Geographic Barrier Hypothesis). Read More

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A systematic review of influenza A virus prevalence and transmission dynamics in backyard swine populations globally.

Porcine Health Manag 2022 Mar 14;8(1):10. Epub 2022 Mar 14.

School of Laboratory Medicine and Medical Sciences, Nelson R. Mandela School of Medicine, College of Health Sciences, University of KwaZulu-Natal, 719 Umbilo Road, Durban, 4001, South Africa.

Background: Backyard swine farming is critical to generating subsistence and food security in rural and peri-urban households in several developing countries. The objective of this systematic review was to analyze the molecular and serological prevalence of influenza A virus (IAV) in backyard swine populations globally.

Results: We identified 34 full-text research articles in NCBI-PubMed and Google Scholar databases that have reported IAV sero- and/or virological prevalence in backyard swine up to 11 July 2021. Read More

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Swine H1N1 Influenza Virus Variants with Enhanced Polymerase Activity and HA Stability Promote Airborne Transmission in Ferrets.

J Virol 2022 04 7;96(7):e0010022. Epub 2022 Mar 7.

Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, USA.

Understanding how animal influenza A viruses (IAVs) acquire airborne transmissibility in humans and ferrets is needed to prepare for and respond to pandemics. Here, we investigated in ferrets the replication and transmission of swine H1N1 isolates P4 and G15, whose majority population had decreased polymerase activity and poor hemagglutinin (HA) stability, respectively. For both isolates, a minor variant was selected and transmitted in ferrets. Read More

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Protective effect of bivalent H1N1 and H3N2 VLP vaccines against Eurasian avian-like H1N1 and recent human-like H3N2 influenza viruses in a mouse model.

Vet Microbiol 2022 Mar 16;266:109370. Epub 2022 Feb 16.

College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510462, China; Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, 510462, China. Electronic address:

Eurasian avian-like (EA) H1N1 swine influenza viruses (SIVs) are currently the most prevalent SIVs in Chinese swine populations, but recent human-like H3N2 SIV subtypes have also been frequently isolated. Hence, there is an urgent need to develop an effective vaccine against both EA H1N1 and recent human-like H3N2 infections. In this study, we utilized the baculovirus expression system to produce virus-like particles (VLPs) containing hemagglutinin protein (HA) and matrix protein (M1) based on A/Swine/Guangdong/YJ4/2014 (H1N1) and A/swine/Guangdong/L22/2010 (H3N2). Read More

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Genetic Variability among Swine Influenza Viruses in Italy: Data Analysis of the Period 2017-2020.

Viruses 2021 12 28;14(1). Epub 2021 Dec 28.

OIE Reference Laboratory for Swine Influenza, Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna (IZSLER), 25124 Brescia, Italy.

Swine play an important role in the ecology of influenza A viruses (IAVs), acting as mixing vessels. Swine (sw) IAVs of H1N1 (including H1N1pdm09), H3N2, and H1N2 subtypes are enzootic in pigs globally, with different geographic distributions. This study investigated the genetic diversity of swIAVs detected during passive surveillance of pig farms in Northern Italy between 2017 and 2020. Read More

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December 2021

Comparison of the pediatric hospitalizations due to COVID-19 and H1N1pdm09 virus infections during the pandemic period.

J Med Virol 2022 05 25;94(5):2055-2059. Epub 2022 Jan 25.

Department of Pediatric Infectious Diseases, Dr. Behçet Uz Child Disease and Pediatric Surgery Training and Research Hospital, Izmir, Turkey.

There are two major pandemics in the new millennium, including the pandemic of swine influenza and the COVID-19 pandemic. These two pandemics affected children as well as the adult population. In this case-control study, we compared children with COVID-19 infection and those with H1N1pdm09 virus infection. Read More

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Characterization of a 2016-2017 Human Seasonal H3 Influenza A Virus Spillover Now Endemic to U.S. Swine.

mSphere 2022 02 12;7(1):e0080921. Epub 2022 Jan 12.

Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State Universitygrid.34421.30, Ames, Iowa, USA.

In 2017, the Iowa State University Veterinary Diagnostic Laboratory detected a reverse-zoonotic transmission of a human seasonal H3 influenza A virus into swine (IAV-S) in Oklahoma. Pairwise comparison between the recently characterized human seasonal H3 IAV-S (H3.2010. Read More

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February 2022

Vaccine-Associated Enhanced Respiratory Disease following Influenza Virus Infection in Ferrets Recapitulates the Model in Pigs.

J Virol 2022 03 5;96(5):e0172521. Epub 2022 Jan 5.

Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, Iowa, USA.

Influenza A virus (IAV) causes respiratory disease in swine and humans. Vaccines are used to prevent influenza illness in both populations but must be frequently updated due to rapidly evolving strains. Mismatch between the circulating strains and the strains contained in vaccines may cause loss of efficacy. Read More

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Inherent Heterogeneity of Influenza A Virus Stability following Aerosolization.

Appl Environ Microbiol 2022 02 5;88(4):e0227121. Epub 2022 Jan 5.

Influenza Division, Centers for Disease Control and Preventiongrid.416738.f, Atlanta, Georgia, USA.

Efficient human-to-human transmission represents a necessary adaptation for a zoonotic influenza A virus (IAV) to cause a pandemic. As such, many emerging IAVs are characterized for transmissibility phenotypes in mammalian models, with an emphasis on elucidating viral determinants of transmission and the role host immune responses contribute to mammalian adaptation. Investigations of virus infectivity and stability in aerosols concurrent with transmission assessments have increased in recent years, enhancing our understanding of this dynamic process. Read More

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February 2022

Low Dose Pig Anti-Influenza Virus Monoclonal Antibodies Reduce Lung Pathology but Do Not Prevent Virus Shedding.

Front Immunol 2021 16;12:790918. Epub 2021 Dec 16.

Host Responses, The Pirbright Institute, Pirbright, United Kingdom.

We have established the pig, a large natural host animal for influenza, with many physiological similarities to humans, as a robust model for testing the therapeutic potential of monoclonal antibodies (mAbs). In this study we demonstrated that prophylactic intravenous administration of 15 mg/kg of porcine mAb pb18, against the K160-163 site of the hemagglutinin, significantly reduced lung pathology and nasal virus shedding and eliminated virus from the lung of pigs following H1N1pdm09 challenge. When given at 1 mg/kg, pb18 significantly reduced lung pathology and lung and BAL virus loads, but not nasal shedding. Read More

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February 2022

Eurasian Avian-like M1 Plays More Important Role than M2 in Pathogenicity of 2009 Pandemic H1N1 Influenza Virus in Mice.

Viruses 2021 11 23;13(12). Epub 2021 Nov 23.

School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.

Reassortant variant viruses generated between 2009 H1N1 pandemic influenza virus [A(H1N1)pdm09] and endemic swine influenza viruses posed a potential risk to humans. Surprisingly, genetic analysis showed that almost all of these variant viruses contained the M segment from A(H1N1)pdm09, which originated from Eurasian avian-like swine influenza viruses. Studies have shown that the A(H1N1)pdm09 M gene is critical for the transmissibility and pathogenicity of the variant viruses. Read More

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November 2021

What Have We Learnt About the Sourcing of Personal Protective Equipment During Pandemics? Leadership and Management in Healthcare Supply Chain Management: A Scoping Review.

Front Public Health 2021 9;9:765501. Epub 2021 Dec 9.

School of Health and Social Care, Swansea University, Swansea, United Kingdom.

During the ongoing COVID-19 pandemic there have been much publicised shortages in Personal Protective Equipment for frontline health care workers, from masks to gowns. Recent previous airborne pandemics provide an opportunity to learn how to effectively lead and manage supply chains during crisis situations. Identifying and plotting this learning against time will reveal what has been learnt, when and, significantly, what can be learnt for the future. Read More

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January 2022

COVID-19 and Future Disease X in Circular Economy Transition: Redesigning Pandemic Preparedness to Prevent a Global Disaster.

Circ Econ Sustain 2021 Jun 28:1-16. Epub 2021 Jun 28.

Bio-Manguinhos, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.

The COVID-19 pandemic exposed a world surprisingly unprepared to respond to the new epidemiological scenario, even the developed countries, in spite of warnings from scientists since the 1990s. These alerts warned on the risks of an exponential increase in emergence of potentially pandemic zoonotic infectious diseases related to disruptive ecological niches in different regions of the globe, such as H1N1 Influenza, SARS, MERS, Zika, avian flu, swine flu, and Ebola, and also on the risks of a future and more lethal Disease X. We examine this global public health failure in anticipating and responding to the pandemic, stressing the urgent need for an innovative global pandemic preparedness system in the current transition from linear economy to a circular economy. Read More

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A SYBR Green-based real-time RT-PCR assay to differentiate the H1N1 influenza virus lineages.

J Virol Methods 2022 02 27;300:114387. Epub 2021 Nov 27.

Laboratory of Infectious Diseases, College of Veterinary Medicine, Key Laboratory of Zoonosis Research, Ministry of Education, Jilin University, Changchun 130062, China. Electronic address:

The H1N1 subtype influenza viruses (H1N1) have been causing persistent epidemics in human, swine and poultry populations since 1918. This subtype has evolved into four relatively stable genetic lineages, including classical swine influenza virus lineage, seasonal human influenza virus lineage, avian influenza virus lineage and Eurasian avian-like swine influenza virus lineage. In this study, four pairs of primers, based on the relatively conserved HA nucleotide regions of each H1N1 genetic lineage, were designed to establish a SYBR Green-based real-time quantitative RT-PCR (qPCR) assay to differentiate between the H1N1 genetic lineages. Read More

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February 2022

Moving the needle on racial disparity: COVID-19 vaccine trust and hesitancy.

Vaccine 2022 01 20;40(1):5-8. Epub 2021 Nov 20.

Utah State University, Logan, UT, USA.

Health equity has grown in prominence during the pandemic. Racial disparities in COVID-19 infections and vaccine hesitancy (differences up to 26%) have generated concerns, research, and interventions with less-than-satisfactory results. Two longitudinal national surveys in the U. Read More

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January 2022

Reassortant Influenza A(H1N1)pdm09 Virus in Elderly Woman, Denmark, January 2021.

Emerg Infect Dis 2021 12;27(12):3202-3205

A case of human infection with influenza A(H1N1)pdm09 virus containing a nonstructural gene highly similar to Eurasian avian-like H1Nx swine influenza virus was detected in Denmark in January 2021. We describe the clinical case and report testing results of the genetic and antigenic characterizations of the virus. Read More

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December 2021

Characterization of Swine Influenza A(H1N2) Variant, Alberta, Canada, 2020.

Emerg Infect Dis 2021 ;27(12):3045-3051

Influenza strains circulating among swine populations can cause outbreaks in humans. In October 2020, we detected a variant influenza A subtype H1N2 of swine origin in a person in Alberta, Canada. We initiated a public health, veterinary, and laboratory investigation to identify the source of the infection and determine whether it had spread. Read More

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December 2021

Respiratory and Intramuscular Immunization With ChAdOx2-NPM1-NA Induces Distinct Immune Responses in H1N1pdm09 Pre-Exposed Pigs.

Front Immunol 2021 3;12:763912. Epub 2021 Nov 3.

Enhanced Host Responses, The Pirbright Institute, Pirbright, United Kingdom.

There is a critical need to develop superior influenza vaccines that provide broader protection. Influenza vaccines are traditionally tested in naive animals, although humans are exposed to influenza in the first years of their lives, but the impact of prior influenza exposure on vaccine immune responses has not been well studied. Pigs are an important natural host for influenza, are a source of pandemic viruses, and are an excellent model for human influenza. Read More

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February 2022

T helper type (Th1/Th2) responses to SARS-CoV-2 and influenza A (H1N1) virus: From cytokines produced to immune responses.

Transpl Immunol 2022 02 10;70:101495. Epub 2021 Nov 10.

Social Determinants of Health Research Center, School of Allied Medical Sciences, Shahrekord University of Medical Sciences, Shahrekord, Iran.. Electronic address:

Cytokines produced by T helper cells (T cells) have essential roles in the body's defense against viruses. Type 1 T helper (Th1) cells are essential for the host defense toward intracellular pathogens while T helper type 2 (Th2) cells are considered to be critical for the helminthic parasites' elimination swine-origin influenza A (H1N1) virus, a disease led to an epidemic in 2009 and rapidly spread globally via human-to-human transmission. Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused a global pandemic in 2020 and is a serious threat to the public health. Read More

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February 2022

Identifying COVID-19 and H1N1 vaccination hesitancy or refusal among health care providers across North America, the United Kingdom, Europe, and Australia: a scoping review protocol.

JBI Evid Synth 2022 01;20(1):173-180

School of Nursing, Dalhousie University, Halifax, NS, Canada.

Objective: The aim of this scoping review is to describe and map the evidence on COVID-19 and H1N1 vaccination hesitancy or refusal among physicians, nurses, and pharmacists across North America, the United Kingdom, Europe, and Australia.

Introduction: When global pandemics occur, including the coronavirus (COVID-19) pandemic, which originated in 2020, and the swine flu influenza pandemic (H1N1) of 2009, there is increased pressure for pharmaceutical companies and government agencies to develop safe and effective vaccines against these highly contagious illnesses. Following development and approvals, it then becomes essential that priority populations, including frontline health care providers, opt to receive these vaccinations to prevent illness and potential transmission to their patients. Read More

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January 2022