RESUMO
Due to their documented epidemiological relevance as hosts for influenza A viruses (IAV), humans, poultry and pigs in backyard production systems (BPS) within wetlands could be key to the emergence of novel IAV variants able to transmit between humans or animals. To better understand the circulation of IAV at the human-animal interface of BPS within wetlands, we studied IAV in backyard duck flocks and pig herds in the Pacific Coast of Guatemala. From April 2013 to October 2014, we estimated the monthly IAV per cent seropositive and viral positive flocks and herds in two resource-limited communities. We detected antibodies in sera against the IAV nucleoprotein through ELISA. We also detected IAV viral RNA in respiratory (ducks and pigs) and cloacal (ducks) swabs through rRT-PCR directed at the matrix gene. We attempted viral isolation in eggs or MDCK cells followed by sequencing from swabs positive for IAV. During our study period, IAV seropositivity in duck flocks was 38%, and viral positivity was 23% (n = 86 BPS sampled). IAV seropositivity in pig herds was 42%, and viral positivity was 20% (n = 90 BPS sampled). Both flocks and herds had detectable antibodies against IAV mostly year-round, and IAV was detected in several months. We isolated an H3N2 virus from one pig sampled at the end of 2013. Standard nucleotide BLAST searches indicate that the isolated virus was similar to seasonal viruses circulating in humans, suggesting human-to-pig transmission. Our data show concurrent circulation of IAV in multiple species of poultry and pigs that were commingled in rudimentary conditions in proximity to humans, but no significant risk factors could be identified.
Assuntos
Vírus da Influenza A , Infecções por Orthomyxoviridae , Doenças dos Suínos , Animais , Patos , Guatemala/epidemiologia , Humanos , Vírus da Influenza A Subtipo H3N2/genética , Nucleoproteínas , Nucleotídeos , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/veterinária , Óvulo , Aves Domésticas , RNA Viral/genética , SuínosRESUMO
We identified 2 poultry workers with conjunctivitis caused by highly pathogenic avian influenza A(H7N3) viruses in Jalisco, Mexico. Genomic and antigenic analyses of 1 isolate indicated relatedness to poultry and wild bird subtype H7N3 viruses from North America. This isolate had a multibasic cleavage site that might have been derived from recombination with host rRNA.
Assuntos
Vírus da Influenza A Subtipo H7N3/genética , Influenza Aviária/epidemiologia , Influenza Aviária/transmissão , Influenza Humana/epidemiologia , Influenza Humana/transmissão , Adulto , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Surtos de Doenças , Feminino , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Humanos , Vírus da Influenza A Subtipo H7N3/classificação , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Dados de Sequência Molecular , Tipagem de Sequências Multilocus , Filogenia , Aves Domésticas , Alinhamento de SequênciaRESUMO
H7 subtype influenza A viruses, responsible for numerous outbreaks in land-based poultry in Europe and the Americas, have caused over 100 cases of confirmed or presumed human infection over the last decade. The emergence of a highly pathogenic avian influenza H7N3 virus in poultry throughout the state of Jalisco, Mexico, resulting in two cases of human infection, prompted us to examine the virulence of this virus (A/Mexico/InDRE7218/2012 [MX/7218]) and related avian H7 subtype viruses in mouse and ferret models. Several high- and low-pathogenicity H7N3 and H7N9 viruses replicated efficiently in the respiratory tract of mice without prior adaptation following intranasal inoculation, but only MX/7218 virus caused lethal disease in this species. H7N3 and H7N9 viruses were also detected in the mouse eye following ocular inoculation. Virus from both H7N3 and H7N9 subtypes replicated efficiently in the upper and lower respiratory tracts of ferrets; however, only MX/7218 virus infection caused clinical signs and symptoms and was capable of transmission to naive ferrets in a direct-contact model. Similar to other highly pathogenic H7 viruses, MX/7218 replicated to high titers in human bronchial epithelial cells, yet it downregulated numerous genes related to NF-κB-mediated signaling transduction. These findings indicate that the recently isolated North American lineage H7 subtype virus associated with human conjunctivitis is capable of causing severe disease in mice and spreading to naive-contact ferrets, while concurrently retaining the ability to replicate within ocular tissue and allowing the eye to serve as a portal of entry.
Assuntos
Conjuntivite/virologia , Vírus da Influenza A Subtipo H7N3/patogenicidade , Infecções por Orthomyxoviridae/virologia , Tropismo Viral , Animais , Modelos Animais de Doenças , Células Epiteliais/virologia , Feminino , Furões , Humanos , Vírus da Influenza A Subtipo H7N3/isolamento & purificação , Masculino , México , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Orthomyxoviridae/transmissão , Sistema Respiratório/virologiaRESUMO
Complete genome sequencing of 22 West Nile virus isolates suggested 2 independent introductions into Mexico. A previously identified mouse-attenuated glycosylation variant was introduced into southern Mexico through the southeastern United States, while a common US genotype appears to have been introduced incrementally into northern Mexico through the southwestern United States.
Assuntos
Febre do Nilo Ocidental/epidemiologia , Vírus do Nilo Ocidental/isolamento & purificação , Animais , Doenças das Aves/epidemiologia , Doenças das Aves/virologia , Aves/classificação , Aves/virologia , Corvos/virologia , Culex/virologia , Doenças dos Cavalos/epidemiologia , Doenças dos Cavalos/virologia , Cavalos/virologia , Humanos , México/epidemiologia , Camundongos , Dados de Sequência Molecular , Análise de Sequência de DNA , Estados Unidos , Virulência , Febre do Nilo Ocidental/virologia , Vírus do Nilo Ocidental/classificação , Vírus do Nilo Ocidental/genética , Vírus do Nilo Ocidental/patogenicidadeRESUMO
West Nile virus has been isolated for the first time in Mexico, from a sick person and from mosquitoes (Culex quinquefasciatus). Partial sequencing and analysis of the 2 isolates indicate that they are genetically similar to other recent isolates from northern Mexico and the western United States.
Assuntos
Culex/virologia , RNA Viral/genética , Vírus do Nilo Ocidental/isolamento & purificação , Animais , Feminino , Humanos , México , Pessoa de Meia-Idade , Filogenia , Texas , Vírus do Nilo Ocidental/genéticaRESUMO
The complete genome sequence of a Mexican West Nile virus isolate, TM171-03, included 46 nucleotide (0.42%) and 4 amino acid (0.11%) differences from the NY99 prototype. Mouse virulence differences between plaque-purified variants of TM171-03 with mutations at the E protein glycosylation motif suggest the emergence of an attenuating mutation.