scholarly journals Isolation of H3N2 Swine Influenza Virus in South Korea

2003 ◽  
Vol 15 (1) ◽  
pp. 30-34 ◽  
Author(s):  
Dae S. Song ◽  
Jae Y. Lee ◽  
Jin S. Oh ◽  
Kwang S. Lyoo ◽  
Kyung J. Yoon ◽  
...  
Keyword(s):  
Influenza Virus ◽  
South Korea ◽  
Respiratory Disease ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Influenza Viruses ◽  
H3n2 Virus ◽  
Pcr Products ◽  
Swine Population ◽  
Swine Herds

Swine influenza is a significant respiratory disease causing occasional reproductive problems in nïve swine herds. Although different subtypes of swine influenza virus (SIV) have been implicated in clinical outbreaks of swine influenza in Asian countries, no virus isolation has been made to identify SIV of subtypes other than the H1N1 subtype in the Korean swine population. In December 1998, an outbreak of acute respiratory disease was identified in a commercial swine farm located in the Kyunggi province of South Korea. A causative agent, which agglutinated rooster red blood cells, was detected from the lungs of 3 piglets from the index herd and was determined to be type A influenza virus using a commercial influenza virus typing kit. Hemagglutination activity (HA) of the isolates was completely inhibited by a swine antiserum against a recent US H3N2 SIV isolate (A/Sw/IA/41305/1998) but not by H1N1 swine antiserum (A/Sw/IA/1979). Reverse transcription–polymerase chain reaction (RT-PCR) revealed all 3 isolates were H3 SIV subtypes. Sequence analysis of hemagglutinin gene PCR products supported the belief that the Korean H3 SIV isolates were genetically similar to the known mammalian H3 influenza viruses. This is the first report on a clinical outbreak of swine influenza caused by the H3N2 virus in Korea.

Phylogeny of Spanish swine influenza viruses isolated from respiratory disease outbreaks and evolution of swine influenza virus within an endemically infected farm

2014 ◽  
Vol 170 (3-4) ◽  
pp. 266-277 ◽  
Author(s):  
Gerard E. Martín-Valls ◽  
Meritxell Simon-Grifé ◽  
Sander van Boheemen ◽  
Miranda de Graaf ◽  
Theo M. Bestebroer ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Respiratory Disease ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Disease Outbreaks ◽  
Influenza Viruses ◽  
Infected Farm

scholarly journals Bat influenza vectored NS1-truncated live vaccine protects pigs against heterologous virus challenge

2020 ◽  
Author(s):  
Jinhwa Lee ◽  
Yonghai Li ◽  
Yuhao Li ◽  
A. Giselle Cino-Ozuna ◽  
Michael Duff ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Live Vaccine ◽  
H3n2 Virus ◽  
Swine Industry ◽  
Vaccine Candidates ◽  
Virus Challenge ◽  
Significant Difference

AbstractSwine influenza is an important disease for the swine industry. Currently used whole inactivated virus (WIV) vaccines can induce vaccine-associated enhanced respiratory disease (VAERD) in pigs when the vaccine strains mismatch with the infected viruses. Live attenuated influenza virus vaccine (LAIV) is effective to protect pigs against homologous and heterologous swine influenza virus infections without inducing VAERD, but has safety concerns due to potential reassortment with circulating viruses. Herein, we used a chimeric bat influenza Bat09:mH3mN2 virus, which contains both surface HA and NA gene open reading frames of the A/swine/Texas/4199-2/1998 (H3N2) and six internal genes from the novel bat H17N10 virus, to develop modified live-attenuated viruses (MLVs) as vaccine candidates which cannot reassort with canonical influenza A viruses by co-infection. Two attenuated MLV vaccine candidates including the virus that expresses a truncated NS1 (Bat09:mH3mN2-NS1-128, MLV1) or expresses both a truncated NS1 and the swine IL-18 (Bat09:mH3mN2-NS1-128-IL-18, MLV2) were generated and evaluated in pigs against a heterologous H3N2 virus using the WIV vaccineb as a control. Compared to the WIV vaccine, both MLV vaccines were able to reduce lesions and virus replication in lungs and limit nasal virus shedding without VAERD, also induced significantly higher levels of mucosal IgA response in lungs and significantly increased numbers of antigen-specific IFN-γ secreting cells against the challenge virus. However, no significant difference was observed in efficacy between the MLV1 and MLV2. These results indicate that bat influenza vectored MLV vaccines can be used as a safe live vaccine to prevent swine influenza.

scholarly journals Swine-Origin H1 Influenza Viruses Isolated from Humans Exhibit Sustained Infectivity in an Aerosol State

2019 ◽  
Vol 85 (10) ◽  
Author(s):  
Joanna A. Pulit-Penaloza ◽  
Jessica A. Belser ◽  
Terrence M. Tumpey ◽  
Taronna R. Maines
Keyword(s):  
Influenza Virus ◽  
Swine Influenza Virus ◽  
Virus Transmission ◽  
Swine Influenza ◽  
Influenza Viruses ◽  
Aerosol State ◽  
The Stability ◽  
Higher Doses ◽  
Enhanced Stability

ABSTRACT The relative importance of influenza virus transmission via aerosols is not fully understood, but experimental data suggest that aerosol transmission may represent a critical mode of influenza virus spread among humans. Decades ago, prototypical laboratory strains of influenza were shown to persist in aerosols; however, there is a paucity of data available covering currently circulating influenza viruses, which differ significantly from their predecessors. In this study, we evaluated the longevity of influenza viruses in aerosols generated in the laboratory. We selected a panel of H1 viruses that exhibit diverse transmission profiles in the ferret model, including four human isolates of swine origin (referred to as variant) and a seasonal strain. By measuring the ratio of viral RNA to infectious virus maintained in aerosols over time, we show that influenza viruses known to transmit efficiently through the air display enhanced stability in an aerosol state for prolonged periods compared to those viruses that do not transmit as efficiently. We then assessed whether H1 influenza virus was still capable of infecting and causing disease in ferrets after being aged in suspended aerosols. Ferrets exposed to very low levels of influenza virus (≤17 PFU) in aerosols aged for 15 or 30 min became infected, with five of six ferrets shedding virus in nasal washes at titers on par with ferrets who inhaled higher doses of unaged influenza virus. We describe here an underreported characteristic of influenza viruses, stability in aerosols, and make a direct connection to the role this characteristic plays in influenza transmission. IMPORTANCE Each time a swine influenza virus transmits to a human, it provides an opportunity for the virus to acquire adaptations needed for sustained human-to-human transmission. Here, we use aerobiology techniques to test the stability of swine-origin H1 subtype viruses in aerosols and evaluate their infectivity in ferrets. Our results show that highly transmissible influenza viruses display enhanced stability in an aerosol state compared to viruses that do not transmit as efficiently. Similar to human-adapted strains, swine-origin influenza viruses are infectious in ferrets at low doses even after prolonged suspension in the air. These data underscore the risk of airborne swine-origin influenza viruses and support the need for continued surveillance and refinement of innovative laboratory methods to investigate mammalian exposure to inhaled pathogens. Determination of the molecular markers that affect the longevity of airborne influenza viruses will improve our ability to quickly identify emerging strains that present the greatest threat to public health.

scholarly journals Mutations in the NS1 Protein of Swine Influenza Virus Impair Anti-Interferon Activity and Confer Attenuation in Pigs

2005 ◽  
Vol 79 (12) ◽  
pp. 7535-7543 ◽  
Author(s):  
Alicia Solórzano ◽  
Richard J. Webby ◽  
Kelly M. Lager ◽  
Bruce H. Janke ◽  
Adolfo García-Sastre ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Nonstructural Protein ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Influenza Viruses ◽  
Model Systems ◽  
Ns1 Protein ◽  
Wild Type ◽  
Virulence Attenuation

ABSTRACT It has been shown previously that the nonstructural protein NS1 of influenza virus is an alpha/beta interferon (IFN-α/β) antagonist, both in vitro and in experimental animal model systems. However, evidence of this function in a natural host has not yet been obtained. Here we investigated the role of the NS1 protein in the virulence of a swine influenza virus (SIV) isolate in pigs by using reverse genetics. The virulent wild-type A/Swine/Texas/4199-2/98 (TX/98) virus and various mutants encoding carboxy-truncated NS1 proteins were rescued. Growth properties of TX/98 viruses with mutated NS1, induction of IFN in tissue culture, and virulence-attenuation in pigs were analyzed and compared to those of the recombinant wild-type TX/98 virus. Our results indicate that deletions in the NS1 protein decrease the ability of the TX/98 virus to prevent IFN-α/β synthesis in pig cells. Moreover, all NS1 mutant viruses were attenuated in pigs, and this correlated with the amount of IFN-α/β induced in vitro. These data suggest that the NS1 protein of SIV is a virulence factor. Due to their attenuation, NS1-mutated swine influenza viruses might have a great potential as live attenuated vaccine candidates against SIV infections of pigs.

scholarly journals Effect of health seeking interval on outcome in swine flu cases attended a tertiary care hospital in southern Rajasthan region of India

2019 ◽  
Vol 6 (7) ◽  
pp. 2910
Author(s):  
Shalabh Sharma ◽  
Yogesh Kumar Singhal
Keyword(s):  
Influenza Virus ◽  
Clinical Care ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Influenza Viruses ◽  
Swine Flu ◽  
Care Hospital ◽  
Health Seeking ◽  
Early Presentation ◽  
Number Of Patients

Background: Swine flu influenza is an infection by H1N1 type of swine influenza virus. Swine influenza virus or swine-origin influenza virus (SIV or S-OIV) is a strain of the family of influenza viruses that’s endemic in swine (pigs). Early diagnosis and treatment is key approach to control the morbidity and mortality associated with swine flu which can be achieved by improving health seeking behaviour of community. Understanding of behaviour of community is essential for planning strategies for prevention and control. Aim of this study is to establish a relation between healthcare interval and outcome of swine flu.Methods: A complete data of all the patients visiting swine flu OPDs, swine flu wards and ICU were maintained for year 2015. Each patient visiting either the swine flu OPD or the swine flu ward, who was suspected clinically to be H1N1 positive were tested for real time PCR. Data was collected in a standardized pre-structured questionnaire.Results: Out of 1247 samples tested for rt-PCR, number of patients found to be swine positive was 491 (39.37%). Total 267 patients were admitted in swine flu ward and ICU, out of them 62 was expired. Clinical care intervals of more than 5 days from onset of symptoms to swab collection, diagnosis and admission were more in female and rural population. Mean duration between onset of symptom to hospitalization, swab collection and diagnosis was significantly higher in deceased patients than survived.Conclusions: Early presentation to healthcare facility is associated with better prognosis and outcome. After patient report to the health care setup, early sample collection and diagnosis help to reduce mortality.

scholarly journals Resurrected ancestral influenza A viruses recapitulate the avian-to-mammalian adaptation of European avian-like swine influenza virus

2021 ◽  
Author(s):  
Wen Su ◽  
Rhodri Harfoot ◽  
Yvonne Su ◽  
Jennifer DeBeauchamp ◽  
Udayan Joseph ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Influenza A ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Polymerase Activity ◽  
Influenza Viruses ◽  
Mammalian Host ◽  
Influenza A Viruses ◽  
Sequence Reconstruction

Abstract The emergence of a pandemic influenza virus may be better anticipated if we better understand the evolutionary steps taken by avian influenza viruses as they adapt to mammals. We used ancestral sequence reconstruction to resurrect viruses representing initial adaptive stages of the European avian-like H1N1 virus as it transitioned from avian to swine hosts. We demonstrate that efficient transmissibility in pigs was gained through stepwise adaptation after 1983. These time-dependent adaptations resulted in changes in hemagglutinin receptor binding specificity and increased viral polymerase activity. An NP-R351K mutation under strong positive selection increased the transmissibility of a reconstructed virus. The stepwise-adaptation of a wholly avian influenza virus to a mammalian host suggests a window where targeted intervention may have highest impact. Successful intervention will, however, require strategic coordination of surveillance and risk assessment activities to identify these adapting viruses and guide pandemic preparedness resources.

scholarly journals Simultaneous infection with porcine reproductive and respiratory syndrome and influenza viruses abrogates clinical protection induced by live attenuated porcine reproductive and respiratory syndrome vaccination

2021 ◽  
Author(s):  
Tiphany Chrun ◽  
Emmanuel Atangana Maze ◽  
Eleni Vatzia ◽  
Veronica Martini ◽  
Basu Paudyal ◽  
...  
Keyword(s):  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Cost Effective ◽  
Influenza Viruses ◽  
H3n2 Virus ◽  
Economic Losses ◽  
Respiratory Syndrome Virus ◽  
Upper Respiratory Tract ◽  
Live Virus ◽  
Clinical Protection

The porcine respiratory disease complex (PRDC) is responsible for significant economic losses in the pig industry worldwide. Porcine reproductive and respiratory syndrome virus (PRRSV) and swine influenza virus are major viral contributors to PRDC. Vaccines are cost-effective measures for controlling PRRS, however, their efficacy in the context of co-infections has been poorly investigated. In this study, we aimed to determine the effect of PRRSV-2 and swine influenza H3N2 virus co-infection on the efficacy of PRRSV modified live virus (MLV) vaccination, which is widely used in the field. Following simultaneous challenge with contemporary PRRSV-2 and H3N2 field isolates, we found that the protective effect of PRRS MLV vaccination on clinical disease and pathology was abrogated, although viral load was unaffected and antibody responses were enhanced. In contrast, co-infection in non-immunized animals reduced PRRSV-2 viremia and H3N2 virus load in the upper respiratory tract and potentiated T cell responses against both PRRSV-2 and H3N2 in the lung. Further analysis suggested that an upregulation of inhibitory cytokines gene expression in the lungs of vaccinated pigs may have influenced responses to H3N2 and PRRSV-2. These findings provide important insights into the effect of viral co-infections on PRRS vaccine efficacy that may help identity more effective vaccination strategies against PRDC in the field.

scholarly journals Antibody responses to influenza viruses in paediatric patients and their contacts at the onset of the 2009 pandemic in Mexico

2015 ◽  
Vol 9 (03) ◽  
pp. 259-266 ◽  
Author(s):  
Guadalupe Miranda-Novales ◽  
Lourdes Arriaga-Pizano ◽  
Cristina Herrera-Castillo ◽  
Rodolfo Pastelin-Palacios ◽  
Nuriban Valero-Pacheco ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Antibody Titre ◽  
Pandemic Influenza ◽  
Swine Influenza ◽  
Influenza Viruses ◽  
H3n2 Virus ◽  
Serological Response ◽  
Pandemic Strain ◽  
Paediatric Patients ◽  
Influenza A H1n1

Introduction: On April 2009, the Mexican Ministry of Health received notification of cases of severe pneumonia mostly affecting young healthy people; this was the beginning of the first influenza pandemic of the 21st century. The nature of the immune response to the influenza A(H1N1)2009 pandemic strain in Mexico at the beginning of the pandemic outbreak has not been completely defined. We describe the serological response to the 2009 pandemic influenza virus in paediatric patients with influenza-like illness, their household contacts (HHCs), and exposed health-care workers (HCWs) at the beginning of the pandemic outbreak in Mexico City. Methodology: thirty pre-epidemic and 129 epidemic samples were collected and serum antibodies were measured against A(H1N1)2009 pandemic virus and two non-pandemic swine influenza viruses by an haemagglutination inhibition assay . Results: 91% (29/32) of the convalescence samples from confirmed patients had an antibody titre ≥ 10 (GMT 25), 63% (41/65) of the HHCs (GMT 12), 41% of HCWs (GMT 6) and 13% (4/30) of pre-epidemic samples (GMT 6) for the pandemic influenza virus. Of the 32 confirmed cases, 60% had an antibody titre ≥ 40 for the pandemic strain, 53% for the A/swine/Iowa(H1N1) virus (GMT 62) and 43% for the A/swine/Texas(H3N2) virus (GMT 66). Conclusion: The antibody response to 2009 pandemic influenza virus was widespread in convalescence samples from patients with confirmed pandemic influenza infection but the GMT was below the protective titre. There was no evidence that antibodies to the swine influenza viruses had cross-protective effect against the 2009 pandemic influenza virus.

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