Abstract Title
Experimental infection of House Sparrows (Passer domesticus) with low pathogenic avian influenza H7N9: effects of urbanization and interactions with natural avipoxvirus infection
Abstract
The house sparrow (Passer domesticus) is a ubiquitous, but declining, species, distributed worldwide in rural and urban areas. We captured rural and urban sparrows maintaining their respective diets in captivity to investigate the effects of habitat and diet on infection with low pathogenic avian influenza virus (LPAIV). Birds were inoculated intrachoanallly with LPAIV H7N9 A/Anas crecca/Spain/1460/2008 and controls with saline. On days 0, 1, 3, 4, 7, 10 and 14 post-infection, blood, oral and cloacal swabs and feathers were collected from 25% individuals per group and tested by real time RT PCR. Clinical signs were mild or absent, however unexpected mortality was observed starting at 4 dpi in urban and 7 dpi in rural sparrows, reaching 8.33% at day 14 dpi in both groups. Viral antigen in tissues and viral excretion were confirmed by immunohistochemistry and real-time RT-PCR in LPAIV-infected birds. Viral shedding occurred from day 1 to 7 dpi, and seroconversion showing mean titres in the haemagglutination inhibition test of >256 in both groups. Natural infection with avipoxvirus was confirmed in all four groups, with initial detection in control groups but peaking at 4 dpi in LPAIV infected birds in absence of disease or mortality.
This study demonstrates that both urban and rural house sparrows are susceptible to the LPAIV H7N9. While mortality, excretion and seroconversion were similar, earlier onset and prolonged excretion was observed in urban birds. Our results also provide circumstantial evidence on the impact of co-infections with viruses to which sparrows may be naturally exposed.
This study demonstrates that both urban and rural house sparrows are susceptible to the LPAIV H7N9. While mortality, excretion and seroconversion were similar, earlier onset and prolonged excretion was observed in urban birds. Our results also provide circumstantial evidence on the impact of co-infections with viruses to which sparrows may be naturally exposed.
Co-Author(s)
Sara Minayo Martina, Alberto Sánchez- Canoa, Rosa Valleb,c, Maria José Valdezb,c, Richard A.J Williamse Natalia Majób,d, Ursula Höflea
a SaBio Research Group, Institute for Game and Wildlife Research IREC (CSIC-UCLM-JCCM), Ciudad Real, Spain
b Unitat mixta d’investigació IRTA-UAB en Sanitat Animal, Centre de Recerca en Sanitat Animal (CReSA,) Campus de la Universitat Autònoma de Barcelona (UAB), Bellaterra, 08193, Catalonia, Spain
c IRTA, Programa de Sanitat Animal, Centre de Recerca en Sanitat Animal (CReSA,), Campus de la Universitat Autònoma de Barcelona (UAB), Bellaterra, 08193, Catalonia, Spain
d Departament de Sanitat i Anatomia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona (UAB), Campus de la UAB, Bellaterra, 08193, Catalonia. Spain
c Department of Genetics, Physiology and Microbiology, Faculty of Biology, Universidad Complutense de Madrid, UCM. Calle Antonio Nováis 12, Ciudad Universitaria, 28040 Madrid, Spain.
Abstract Category
Mortality estimations, impacts on harvest, conservation considerations, and potential mitigation strategies in wild birds