scholarly journals A human case of swine influenza virus infection in Europe – implications for human health and research

2009 ◽  
Vol 14 (7) ◽  
Author(s):  
K Van Reeth ◽  
A Nicoll
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Direct Evidence ◽  
Genetic Material ◽  
Swine Influenza Virus ◽  
Influenza Virus Infection ◽  
Swine Influenza ◽  
Human Case ◽  
Influenza Viruses ◽  
Avian Influenza Viruses

Swine are susceptible to the same influenza A virus subtypes as humans – H1N1, H3N2 and H1N2 - and the histories of influenza in pigs and people are closely linked. Many swine influenza viruses are a result of reassortment and their genes are composed of human and avian and/or swine virus genes. Indeed, it is known that both human and avian influenza viruses occasionally transmit to pigs, and that pigs can serve as "mixing vessels" for these viruses, meaning that viruses can exchange genetic material and lead to the production of a new "hybrid" virus. This has led to the thinking that perhaps pandemic viruses could emerge following reassortment in pigs. However, since nobody has observed the start of a pandemic, there remains no direct evidence to make this more than a theory.

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 High Risk of Influenza Virus Infection Among Swine Workers: Examining a Dynamic Cohort in China

2019 ◽  
Vol 71 (3) ◽  
pp. 622-629 ◽  
Author(s):  
Laura K Borkenhagen ◽  
Guo-Lin Wang ◽  
Ryan A Simmons ◽  
Zhen-Qiang Bi ◽  
Bing Lu ◽  
...  
Keyword(s):  
Influenza Virus ◽  
High Risk ◽  
Virus Infection ◽  
Influenza A ◽  
Swine Influenza Virus ◽  
Influenza Virus Infection ◽  
Swine Influenza ◽  
Influenza A Viruses ◽  
Increased Risk ◽  
Swine Workers

Abstract Background China is thought to be a hotspot for zoonotic influenza virus emergence, yet there have been few prospective studies examining the occupational risks of such infections. Methods We present the first 2 years of data collected from a 5-year, prospective, cohort study of swine-exposed and -unexposed participants at 6 swine farms in China. We conducted serological and virological surveillance to examine evidence for swine influenza A virus infection in humans. Results Of the 658 participants (521 swine-exposed and 137 swine-unexposed), 207 (31.5%) seroconverted against at least 1 swine influenza virus subtype (swine H1N1 or H3N2). Swine-exposed participants’ microneutralization titers, especially those enrolled at confined animal feeding operations (CAFOs), were higher against the swine H1N1 virus than were other participants at 12 and 24 months. Despite elevated titers, among the 187 study subjects for whom we had complete follow-up, participants working at swine CAFOs had significantly greater odds of seroconverting against both the swine H1N1 (odds ratio [OR] 19.16, 95% confidence interval [CI] 3.55–358.65) and swine H3N2 (OR 2.97, 95% CI 1.16–8.01) viruses, compared to unexposed and non-CAFO swine workers with less intense swine exposure. Conclusions While some of the observed increased risk against swine viruses may have been explained by exposure to human influenza strains, study data suggest that even with elevated preexisting antibodies, swine-exposed workers were at high risk of infection with enzootic swine influenza A viruses.

scholarly journals A single dose vaccination with an elastase-dependent H1N1 live attenuated swine influenza virus protects pigs from challenge with 2009 pandemic H1N1 virus

2014 ◽  
Vol 64 (1) ◽  
pp. 10-23
Author(s):  
Aleksandar Mašić ◽  
Niziti Woldeab ◽  
Carissa Embury-Hyatt ◽  
Yan Zhou ◽  
Shawn Babiuk
Keyword(s):  
Influenza Virus ◽  
Single Dose ◽  
Influenza A Virus ◽  
Neutralizing Antibodies ◽  
Influenza A ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Influenza Viruses ◽  
Virus Infections ◽  
Intranasal Route

Abstract The 2009 outbreak of H1N1 influenza A viruses in humans underscored the importance of pigs in influenza A virus evolution and the emergence of novel viruses with pandemic potential. In addition, influenza A virus infections continued to cause production losses in the agricultural industry resulting in a significant drop of profit. The primary method to control influenza A virus infections in pigs is through vaccination. Previously we demonstrated that two doses of an elastase-dependent live attenuated swine influenza virus administered by either the intratracheal or intranasal route can provide a high degree of protection in pigs against challenge with both homologous and different heterologous swine influenza viruses. Here we report the protection efficacy of a single dose elastase-dependent live attenuated swine influenza virus administered by the intranasal route against challenge with homologous subtypic H1N1 2009 pandemic swine-like influenza virus. Protection was observed in the absence of neutralizing antibodies specific for H1N1 2009 in sera.

scholarly journals Influenza at the animal–human interface: a review of the literature for virological evidence of human infection with swine or avian influenza viruses other than A(H5N1)

2014 ◽  
Vol 19 (18) ◽  
Author(s):  
G S Freidl ◽  
A Meijer ◽  
E de Bruin ◽  
M de Nardi ◽  
O Munoz ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Influenza A ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Human Infection ◽  
Influenza Viruses ◽  
Diagnostic Methods ◽  
World Health ◽  
Review Of The Literature

Factors that trigger human infection with animal influenza virus progressing into a pandemic are poorly understood. Within a project developing an evidence-based risk assessment framework for influenza viruses in animals, we conducted a review of the literature for evidence of human infection with animal influenza viruses by diagnostic methods used. The review covering Medline, Embase, SciSearch and CabAbstracts yielded 6,955 articles, of which we retained 89; for influenza A(H5N1) and A(H7N9), the official case counts of the World Health Organization were used. An additional 30 studies were included by scanning the reference lists. Here, we present the findings for confirmed infections with virological evidence. We found reports of 1,419 naturally infected human cases, of which 648 were associated with avian influenza virus (AIV) A(H5N1), 375 with other AIV subtypes, and 396 with swine influenza virus (SIV). Human cases naturally infected with AIV spanned haemagglutinin subtypes H5, H6, H7, H9 and H10. SIV cases were associated with endemic SIV of H1 and H3 subtype descending from North American and Eurasian SIV lineages and various reassortants thereof. Direct exposure to birds or swine was the most likely source of infection for the cases with available information on exposure.

scholarly journals Elastase-Dependent Live Attenuated Swine Influenza A Viruses Are Immunogenic and Confer Protection against Swine Influenza A Virus Infection in Pigs

2009 ◽  
Vol 83 (19) ◽  
pp. 10198-10210 ◽  
Author(s):  
Aleksandar Masic ◽  
Jayaum S. Booth ◽  
George K. Mutwiri ◽  
Lorne A. Babiuk ◽  
Yan Zhou
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Influenza A ◽  
Swine Influenza Virus ◽  
Influenza Virus Infection ◽  
Swine Influenza ◽  
Cell Mediated Immunity ◽  
Influenza A Viruses ◽  
Live Virus ◽  
Siv Infection

ABSTRACT Influenza A viruses cause significant morbidity in swine, resulting in a substantial economic burden. Swine influenza virus (SIV) infection also poses important human public health concerns. Vaccination is the primary method for the prevention of influenza virus infection. Previously, we generated two elastase-dependent mutant SIVs derived from A/Sw/Saskatchewan/18789/02(H1N1): A/Sw/Sk-R345V (R345V) and A/Sw/Sk-R345A (R345A). These two viruses are highly attenuated in pigs, making them good candidates for a live-virus vaccine. In this study, the immunogenicity and the ability of these candidates to protect against SIV infection were evaluated in pigs. We report that intratracheally administrated R345V and R345A induced antigen-specific humoral and cell-mediated immunity characterized by increased production of immunoglobulin G (IgG) and IgA antibodies in the serum and in bronchoalveolar lavage fluid, high hemagglutination inhibition titers in serum, an enhanced level of lymphocyte proliferation, and higher numbers of gamma interferon-secreting cells at the site of infection. Based on the immunogenicity results, the R345V virus was further tested in a protection trial in which pigs were vaccinated twice with R345V and then challenged with homologous A/Sw/Saskatchewan/18789/02, H1N1 antigenic variant A/Sw/Indiana/1726/88 or heterologous subtypic H3N2 A/Sw/Texas/4199-2/9/98. Our data showed that two vaccinations with R345V provided pigs with complete protection from homologous H1N1 SIV infection and partial protection from heterologous subtypic H3N2 SIV infection. This protection was characterized by significantly reduced macroscopic and microscopic lung lesions, lower virus titers from the respiratory tract, and lower levels of proinflammatory cytokines. Thus, elastase-dependent SIV mutants can be used as live-virus vaccines against swine influenza in pigs.

scholarly journals CHANGING VIRAL SUSCEPTIBILITY OF A HUMAN CELL LINE IN CONTINUOUS CULTIVATION

1961 ◽  
Vol 113 (1) ◽  
pp. 95-110 ◽  
Author(s):  
Sam C. Wong ◽  
Edwin D. Kilbourne
Keyword(s):  
Influenza Virus ◽  
Cell Line ◽  
Influenza A ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Continuous Cultivation ◽  
Influenza Viruses ◽  
Infective Virus ◽  
Serial Transfer ◽  
Variant Cell

During its serial transfer and cultivation in this laboratory, a human conjunctival cell line (Chang) was observed to change in morphology. Concurrently no change was noted in the susceptibility of the cells to viruses capable of infecting the original cell line. However, it was noted that the derived variant cell line had acquired susceptibility to the induction of cytopathic effects and incomplete virus formation by several strains of influenza viruses. It was then discovered that swine influenza virus and the N-WS strain of influenza A virus could be serially propagated in the derived cell line with production of infective virus. The swine virus required adaptation, but the N-WS strain did not. N-WS and swine influenza viruses multiply with infective virus formation only in the variant conjunctival cell and in no other cell line. Antigenic, cytologic, and virologic evidence is presented that the influenza virus-susceptible variant cell is of human origin and is not a contaminating cell exogenously introduced. Transition of a cell line from complete insusceptibility to susceptibility to virus infection and multiplication has not been described previously.

Epidemiological Investigation of Influenza a Viruses in Laboratory Swine and Dogs in Shanghai

2011 ◽  
Vol 393-395 ◽  
pp. 733-736
Author(s):  
Xiao Hua Yang ◽  
Xiao Feng Wei ◽  
Jian Hua Hu ◽  
Xiong Wei Liu ◽  
Shao Jin Chen
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Positive Sample ◽  
Influenza Viruses ◽  
Security Measures ◽  
Influenza A Viruses ◽  
Canine Influenza ◽  
Epidemiological Situation

Swine and canine influenza, which is acute viral respiratory infectious disease, can do great threat to the health of people and animals. What’s more, swine as an intermediate host for the transmission of avian influenza viruses to humans, it’s very important to supervise the epidemiological situation of swine influenza virus (SIV) infections all over the world. The major aim of this paper was to investigate the epidemiological situation of influenza A viruses in laboratory swine and dogs in shanghai and surrounding area from January 2010 to March 2011. There were 109 throat swabs collected from swine and 35 from dogs. Based on RT-PCR, we have got only one swine influenza virus-positive sample and none canine influenza virus-positive. In addition, this survey not only gives a data about the epidemiological situation of swine and canine influenza, but also provides a basis and guarantee for taking a timely and effective security measures.

scholarly journals Emergence of the pandemic H1N1 2009 influenza A virus in swine herds in Poland

2013 ◽  
Vol 57 (3) ◽  
pp. 293-300 ◽  
Author(s):  
Iwona Markowska-Daniel ◽  
Kinga Urbaniak ◽  
Marian Porowski ◽  
Paweł Karbowiak ◽  
Andrzej Kowalczyk ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A Virus ◽  
Influenza A ◽  
Genetic Material ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
H1n1 Influenza ◽  
Molecular Techniques ◽  
Pandemic H1n1 ◽  
Swine Herds

Abstract The outbreaks of pandemic H1N1 influenza A virus (pdm-like H1N1 2009), detected for the first time in farrow-to-finish farms in Poland, were described. The nasal swabs and lung tissue collected from diseased/dead animals were tested using molecular techniques (RRT-PCR, MRT-PCR, RT-PCR, SSG-PCR, sequencing) and virus isolation. The amplification of the genetic material extracted from the tested samples confirmed the presence of the M1 gene sequence of type A influenza virus. Using MRT-PCRs no products characteristic for HA and NA of any swine influenza virus subtypes were obtained. Using SSGPCR, products specific for pandemic HA and NA gene fragments were detected. Six new pdm-like H1N1 2009 strains were isolated and characterised. Phylogenetic analysis of the HA and NA genes revealed that they belong to one lineage with the pandemic strain A/California/04/2009 and other human strains, including human strains isolated in Poland in 2011.

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.

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