Abstract
BackgroundAquatic waterfowl, particularly those in the order Anseriformes and Charadriiformes, are the ecological reservoir of avian influenza viruses (AIVs). Dabbling ducks play a recognized role in the maintenance and transmission of AIVs. Furthermore, the pathogenesis of highly pathogenic AIV (HPAIV) in dabbling ducks is well characterized. In contrast, the role of diving ducks in HPAIV maintenance and transmission remains unclear. In this study, the pathogenesis of a North American A/Goose/1/Guangdong/96-lineage clade 2.3.4.4 group A H5N2 HPAIV, A/Northern pintail/Washington/40964/2014, in diving sea ducks (surf scoters, Melanitta perspicillata) was characterized.ResultsIntrachoanal inoculation of surf scoters with A/Northern pintail/Washington/40964/2014 (H5N2) HPAIV induced mild transient clinical disease whilst concomitantly shedding high virus titers for up to 10 days post-inoculation (dpi), particularly from the oropharyngeal route. Virus shedding, albeit at low levels, continued to be detected up to 14 dpi. Two aged ducks that succumbed to HPAIV infection had pathological evidence for co-infection with duck enteritis virus, which was confirmed by molecular approaches. Abundant HPAIV antigen was observed in visceral and central nervous system organs and was associated with histopathological lesions.ConclusionsCollectively, surf scoters, are susceptible to HPAIV infection and excrete high titers of HPAIV from the respiratory and cloacal tracts whilst being asymptomatic. The susceptibility of diving sea ducks to H5 HPAIV highlights the need for additional research and surveillance to further understand the contribution of diving ducks to HPAIV ecology.
Highlights
Aquatic waterfowl, those in the order Anseriformes and Charadriiformes, are the ecological reservoir of avian influenza viruses (AIVs)
As all CL temperatures recorded were < 42.0 °C, it was considered that highly pathogenic AIV (HPAIV) infection did not induce fever in surf scoters
Whilst one index virus from the North American Gs/ Gd/96-lineage 2014 HPAIV outbreak, A/gyrfalcon/ Washington/41088–6/2014 (H5N8), is a wholly Eurasian H5Nx virus, the NP/WA/14 (H5N2) HPAIV characterized in this study is of mixed origin, with evidence for reassortment with North American low pathogenicity avian influenza viruses [44]
Summary
Those in the order Anseriformes and Charadriiformes, are the ecological reservoir of avian influenza viruses (AIVs). Luczo et al BMC Veterinary Research (2020) 16:351 asymptomatic whilst shedding HPAIV [4,5,6,7,8,9] This unique characteristic of HPAIV infection dynamics in aquatic birds has likely facilitated the global movement of HPAIVs in migratory birds. The North American Pacific flyway overlaps the West Pacific flyway, which itself overlaps the East Asian-Australasian flyway that encompasses China, Korea and much of Southeast Asia. This global flyway connection eventuated in the first detection of the Gs/Gd/96-lineage H5 HPAIV in North America in 2014 [11]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
