Understanding the ecological drivers of avian influenza virus infection in wildfowl: a continental-scale study across Africa
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Date
2011-10
Journal Title
Journal ISSN
Volume Title
Publisher
The Royal Society
Abstract
Despite considerable effort for surveillance of wild birds for avian influenza viruses (AIVs), empirical
investigations of ecological drivers of AIV prevalence in wild birds are still scarce. Here we used a
continental-scale dataset, collected in tropical wetlands of 15 African countries, to test the relative roles of
a range of ecological factors on patterns of AIV prevalence in wildfowl. Seasonal and geographical variations
in prevalence were positively related to the local density of the wildfowl community and to the wintering
period of Eurasian migratory birds in Africa. The predominant influence of wildfowl density with no influence
of climatic conditions suggests, in contrast to temperate regions, a predominant role for inter-individual
transmission rather than transmission via long-lived virus persisting in the environment. Higher prevalences
were found in Anas species than in non-Anas species even when we account for differences in their foraging
behaviour (primarily dabbling or not) or their geographical origin (Eurasian or Afro-tropical), suggesting the
existence of intrinsic differences between wildfowl taxonomic groups in receptivity to infection. Birds were
found infected as often in oropharyngeal as in cloacal samples, but rarely for both types of sample
concurrently, indicating that both respiratory and digestive tracts may be important for AIV replication.
Description
Ecological drivers of influenza in birds
Keywords
influenza A virus, pathogen transmission, disease ecology, wild birds, tropical, migration
Citation
Gaidet, N. et al., 2012. Understanding the ecological drivers of avian influenza virus infection in wildfowl: a continental-scale study across Africa. Proceedings. Biological sciences / The Royal Society, 279(1731), pp.1131–41.