RESUMO
Despite evidence for avian influenza A virus (AIV) transmission between wild and domestic ecosystems, the roles of bird migration and poultry trade in the spread of viruses remain enigmatic. In this study, we integrate ecosystem interactions into a phylogeographic model to assess the contribution of wild and domestic hosts to AIV distribution and persistence. Analysis of globally sampled AIV datasets shows frequent two-way transmission between wild and domestic ecosystems. In general, viral flow from domestic to wild bird populations was restricted to within a geographic region. In contrast, spillover from wild to domestic populations occurred both within and between regions. Wild birds mediated long-distance dispersal at intercontinental scales whereas viral spread among poultry populations was a major driver of regional spread. Viral spread between poultry flocks frequently originated from persistent lineages circulating in regions of intensive poultry production. Our analysis of long-term surveillance data demonstrates that meaningful insights can be inferred from integrating ecosystem into phylogeographic reconstructions that may be consequential for pandemic preparedness and livestock protection.
Assuntos
Aves/virologia , Vírus da Influenza A , Influenza Aviária/epidemiologia , Pandemias/veterinária , Aves Domésticas/virologia , Animais , Animais Selvagens/virologia , Ecossistema , FilogeografiaRESUMO
Swine influenza is a continual problem for the Swine industry and can pose a public health threat as evidenced by the 2009 H1N1 influenza virus pandemic. Given its importance, it is not surprising to find papers describing the disease from the early 20th century. In this chapter, we discuss the history of Swine influenza, the important role swine influenza virus has played in our understanding of influenza virus pathogenesis and virology, and its impact on public health worldwide.
Assuntos
Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Humana/história , Infecções por Orthomyxoviridae/história , Infecções por Orthomyxoviridae/veterinária , Doenças dos Suínos/história , Animais , História do Século XX , História do Século XXI , Humanos , Influenza Humana/epidemiologia , Influenza Humana/virologia , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/virologia , Pandemias/história , Saúde Pública/história , Suínos , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/virologia , Zoonoses/virologiaRESUMO
We evaluated seropositivity to swine and human H1 influenza viruses in 74 swine farm owners, employees, their family members, and veterinarians in rural south-central Wisconsin, compared with 114 urban Milwaukee, Wisconsin, residents. The number of swine farm participants with positive serum hemagglutination-inhibition (HI) antibody titers > or = 40 to swine influenza viruses (17/74) was significantly higher (p<0.001) than the number of seropositive urban control samples (1/114). The geometric mean serum HI antibody titers to swine influenza viruses were also significantly higher (p<0.001) among the farm participants. Swine virus seropositivity was significantly (p<0.05) associated with being a farm owner or a farm family member, living on a farm, or entering the swine barn > or = 4 days/week. Because pigs can play a role in generating genetically novel influenza viruses, swine farmers may represent an important sentinel population to evaluate the emergence of new pandemic influenza viruses.
