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Viruses ; 13(2)2021 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-33567525


Avian influenza virus (AIV) subtypes H5 and H7 are capable of mutating from low to high pathogenicity strains, causing high mortality in poultry with significant economic losses globally. During 2015, two outbreaks of H7N7 low pathogenicity AIV (LPAIV) in Germany, and one each in the United Kingdom (UK) and The Netherlands occurred, as well as single outbreaks of H7N7 high pathogenicity AIV (HPAIV) in Germany and the UK. Both HPAIV outbreaks were linked to precursor H7N7 LPAIV outbreaks on the same or adjacent premises. Herein, we describe the clinical, epidemiological, and virological investigations for the H7N7 UK HPAIV outbreak on a farm with layer chickens in mixed free-range and caged units. H7N7 HPAIV was identified and isolated from clinical samples, as well as H7N7 LPAIV, which could not be isolated. Using serological and molecular evidence, we postulate how the viruses spread throughout the premises, indicating potential points of incursion and possible locations for the mutation event. Serological and mortality data suggested that the LPAIV infection preceded the HPAIV infection and afforded some clinical protection against the HPAIV. These results document the identification of a LPAIV to HPAIV mutation in nature, providing insights into factors that drive its manifestation during outbreaks.

Subtipo H7N7 del Virus de la Influenza A/genética , Subtipo H7N7 del Virus de la Influenza A/patogenicidad , Gripe Aviar/virología , Enfermedades de las Aves de Corral/virología , Animales , Anticuerpos Antivirales/sangre , Pollos , Brotes de Enfermedades/veterinaria , Granjas , Genoma Viral/genética , Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Glicoproteínas Hemaglutininas del Virus de la Influenza/inmunología , Subtipo H7N7 del Virus de la Influenza A/clasificación , Subtipo H7N7 del Virus de la Influenza A/inmunología , Gripe Aviar/epidemiología , Gripe Aviar/patología , Gripe Aviar/transmisión , Mutación , Filogenia , Enfermedades de las Aves de Corral/epidemiología , Enfermedades de las Aves de Corral/patología , Enfermedades de las Aves de Corral/transmisión , Reino Unido/epidemiología , Esparcimiento de Virus/genética
Trop Anim Health Prod ; 49(6): 1117-1124, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28523387


The objective of this study was to evaluate the seroprevalence and identify the strains of swine influenza virus (SwIV), as well as the seroprevalence of porcine parvovirus (PPV), transmissible gastroenteritis virus (TGEV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine respiratory coronavirus (PRCV), porcine circovirus type 2 (PCV-2), and classical swine fever virus (CSFV) in pigs in Trinidad and Tobago (T&T). Blood samples (309) were randomly collected from pigs at farms throughout T&T. Serum samples were tested for the presence of antibodies to the aforementioned viruses using commercial ELISA kits, and the circulating strains of SwIV were identified by the hemagglutination inhibition test (HIT). Antibodies against SwIV were detected in 114 out of the 309 samples (37%). Out of a total of 26 farms, 14 tested positive for SwIV antibodies. HI testing revealed high titers against the A/sw/Minnesota/593/99 H3N2 strain and the pH1N1 2009 pandemic strain. Antibodies against PPV were detected in 87 out of the 309 samples (28%), with 11 out of 26 farms testing positive for PPV antibodies. Antibodies against PCV-2 were detected in 205 out of the 309 samples tested (66%), with 25 out of the 26 farms testing positive for PCV-2 antibodies. No antibodies were detected in any of the tested pigs to PRRSV, TGEV, PRCV, or CSFV.

Orthomyxoviridae/aislamiento & purificación , Enfermedades de los Porcinos/epidemiología , Virosis/veterinaria , Animales , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/veterinaria , Infecciones por Orthomyxoviridae/virología , Prevalencia , Estudios Seroepidemiológicos , Porcinos , Enfermedades de los Porcinos/virología , Trinidad y Tobago/epidemiología , Virosis/epidemiología , Virosis/virología
PLoS One ; 5(2): e9068, 2010 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-20140096


The declaration of the human influenza A pandemic (H1N1) 2009 (H1N1/09) raised important questions, including origin and host range [1], [2]. Two of the three pandemics in the last century resulted in the spread of virus to pigs (H1N1, 1918; H3N2, 1968) with subsequent independent establishment and evolution within swine worldwide [3]. A key public and veterinary health consideration in the context of the evolving pandemic is whether the H1N1/09 virus could become established in pig populations [4]. We performed an infection and transmission study in pigs with A/California/07/09. In combination, clinical, pathological, modified influenza A matrix gene real time RT-PCR and viral genomic analyses have shown that infection results in the induction of clinical signs, viral pathogenesis restricted to the respiratory tract, infection dynamics consistent with endemic strains of influenza A in pigs, virus transmissibility between pigs and virus-host adaptation events. Our results demonstrate that extant H1N1/09 is fully capable of becoming established in global pig populations. We also show the roles of viral receptor specificity in both transmission and tissue tropism. Remarkably, following direct inoculation of pigs with virus quasispecies differing by amino acid substitutions in the haemagglutinin receptor-binding site, only virus with aspartic acid at position 225 (225D) was detected in nasal secretions of contact infected pigs. In contrast, in lower respiratory tract samples from directly inoculated pigs, with clearly demonstrable pulmonary pathology, there was apparent selection of a virus variant with glycine (225G). These findings provide potential clues to the existence and biological significance of viral receptor-binding variants with 225D and 225G during the 1918 pandemic [5].

Subtipo H1N1 del Virus de la Influenza A/patogenicidad , Infecciones por Orthomyxoviridae/veterinaria , Enfermedades de los Porcinos/virología , Replicación Viral , Animales , Antígenos Virales/análisis , Antígenos Virales/inmunología , Secuencia de Bases , Embrión de Pollo , Brotes de Enfermedades , Hemaglutininas Virales/química , Hemaglutininas Virales/genética , Humanos , Inmunohistoquímica , Subtipo H1N1 del Virus de la Influenza A/genética , Subtipo H1N1 del Virus de la Influenza A/inmunología , Gripe Humana/epidemiología , Gripe Humana/virología , Mutación , Infecciones por Orthomyxoviridae/patología , Infecciones por Orthomyxoviridae/transmisión , Sistema Respiratorio/metabolismo , Sistema Respiratorio/patología , Sistema Respiratorio/virología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de Secuencia de ADN , Porcinos , Enfermedades de los Porcinos/patología , Proteínas de la Matriz Viral/genética