Towards a new, ecologically targeted approach to monitoring wild bird populations for avian influenza viruses

Abstract

Prevalence monitoring of avian influenza in wild bird populations is important to estimate risks for the occurrence of potentially zoonotic and economically disastrous outbreaks of highly pathogenic avian influenza virus (AIV) in poultry worldwide. A targeted, cost-effective monitoring method for AIV in wild birds was developed, which is based on monitoring results for AIV in Germany and information on the distribution and abundance of wild bird species in selected habitat types. Spatial data were combined with virological and outbreak data for the period of 1 January 2006 to 31 December 2010. Using Germany as an example, we identified 11 indicator species. By concentrating monitoring efforts on these species in spatially confined locations, we propose a targeted and more cost-effective risk-based AIV monitoring approach that can be adapted universally for the identification of wild bird indicator species worldwide with the perspective of reducing sample sizes (and costs) without impairing the validity of the results.

Fig. 1.

Selected wild bird species present at ⩾1 Ramsar site with positive H5/H7 identification in Ramsar districts. The selected wild bird species belong to the five most abundant species at ⩾1 Ramsar sites and tested positive for H5/H7 in Ramsar districts from 1 January 2006 to 31 December 2010, in Germany. Anas platyrhynchos (Mallard Duck), Aythya fuligula (Tufted Duck), Anser albifrons (White-fronted Goose), Aythya ferina (Common Pochard), Anser fabalis (Bean Goose), Anser anser (Greylag Goose), Bucephala clangula (Common Goldeneye), Fulica atra (Eurasian Coot), Podiceps cristatus (Great Crested Grebe), Larus argentatus (European Herring Gull), Cygnus Cygnus (Whooper Swan), Cygnus olor (Mute Swan), Branta canadensis (Canada Goose), Podiceps nigricollis (Black-necked Grebe), Phalacrocorax carbo (Great Cormorant).

Fig. 2

[colour online]. Administrative districts where H5/H7 was detected in wild birds or poultry from 1 January 2006 to 31 December 2010, compared to the distribution of Ramsar districts in Germany. The numbers 1–34 (within a circle) refer to the 34 Ramsar sites in Germany.

Fig. 3.

Number of bird families with identification of H5/H7 in Ramsar districts compared to bird orders present at Ramsar sites. The number of wild bird and poultry families belonging to the bird orders of the five most abundant wild bird species at Ramsar sites were compared to the number of families per order with positive H5/H7 identification in Ramsar districts from 1 January 2006 to 31 December 2010, in Germany. Accipitriformes (birds of prey), Galliformes (gallinaceous birds), Charadriiformes (shorebirds and relatives), Gruiformes (‘crane-like’ birds), Anseriformes (ducks, geese, swans and relatives), Pelecaniformes (pelicans, tropicbirds, cormorants and relatives), Podicipediformes (grebes), Caprimulgiformes (nightbirds), Coraciiformes (kingfishers and relatives), Passeriformes (perching birds).