Avian Influenza Virus (H11N9) in Migratory Shorebirds Wintering in the Amazon Region, Brazil

Abstract

Aquatic birds are the natural reservoir for avian influenza viruses (AIV). Habitats in Brazil provide stopover and wintering sites for water birds that migrate between North and South America. The current study was conducted to elucidate the possibility of the transport of influenza A viruses by birds that migrate annually between the Northern and Southern Hemispheres. In total, 556 orotracheal/cloacal swab samples were collected for influenza A virus screening using real-time RT-PCR (rRT-PCR). The influenza A virus-positive samples were subjected to viral isolation. Four samples were positive for the influenza A matrix gene by rRT-PCR. From these samples, three viruses were isolated, sequenced and characterized. All positive samples originated from a single bird species, the ruddy turnstone (Arenaria interpres), that was caught in the Amazon region at Caeté Bay, Northeast Pará, at Ilha de Canelas. To our knowledge, this is the first isolation of H11N9 in the ruddy turnstone in South America.

Migratory birds in southern Brazil are a source of multiple avian influenza virus subtypes

“…In South America, AIV has been confirmed in wild birds in multiple years in Argentina (H13N9, H1N1, H6N2, and H9N2),13, 39, 40 Bolivia (H7N3),41 (H7N3),42 Colombia (H5N2),19 Peru (H3N8, H4N5, H10N9, and H13N2),42, 43 and Brazil (H11N9) 20. However, the H6N1 subtype has not previously been identified in shorebirds.…”

“…The RNA was eluted into 80 μL of RNase‐free water. All samples were screened for the presence of the AIV matrix gene by one‐step real‐time reverse transcriptase (RT)‐PCR, using an AIV‐M TaqMan Reagents Kit (Applied Biosystems, Foster City, CA, USA) 20, 22…”

Investigation of Influenza A, West Nile and Newcastle Disease Viruses in Birds from the Pantanal Wetlands of Mato Grosso, Brazil

“…On the other hand, Kawamoto et al (2005) and Soares et al (2005) detected the presence of Influenza A viruses in wild and migratory birds in the state of São Paulo. The first subtype H11N9 isolated from migratory birds collected in the Amazon region was recently reported, and was found to present a very high similarity with viral subtypes described in North America (Araujo et al, 2014). Therefore, the lack of detection of the viruses in the birds of present study may be associated with the captured species, which were mostly resident species with terrestrial habits.…”

“…Despite the low incidence of NDV and Influenza virus in Brazil, it is essential to monitor these virus in scientific studies because Brazil is one of the world's largest exporters of poultry products. In North America and most European countries, the Avian Influenza virus is constantly monitored in wild birds, whereas there still is a significant gap in the knowledge on those viruses in wild birds in South America, and particularly in Brazil (Araujo et al, 2014). In summary, this study highlights the need for further in-depth research involving the continuous monitoring of the birds in the Pantanal region, and in particular, to expand sampling during every season in order to include a wider variety of avian species, which are considered potential reservoirs of infectious diseases.…”

“…Surveys of Influenza virus in bird specimens collected in the state of São Paulo, Brazil revealed high viral loads, emphasizing the need to monitor birds as reservoirs of Avian Influenza (Kawamoto et al, 2005). The first case of Avian Influenza Virus H11N9 isolated from migratory birds in South America was recently reported in the Amazon region (Araujo et al, 2014). However, the pathogenicity of those H11N9 subtypes was considered low.…”