Assessing the exposure of German and Austrian bird ringers to West Nile virus (Flavivirus) and evaluating their potential risk of infection

West Nile virus (WNV) is a mosquito-borne Flavivirus with birds as its natural reservoir. Mosquitoes are able to transmit WNV to humans. In Europe, WNV is most probably imported by migrating birds from WNV-endemic regions. In this study, the risk of WNV infection during bird-ringing activities in Germany and Austria was investigated. Several serological test systems were used to study WNV antibody prevalence among 137 bird ringers. Neutralising antibodies were detected in three of the bird ringers. This seropositivity could be explained by alternative factors such as traveling to endemic areas. The application of different serological methods showed that WNV IgG ELISAs were less specific than WNV IgG immunofluorescence tests (IFT). The neutralisation test (NT) appears to be the gold standard for Flavivirus differentiation. At present, we assume that bird-ringing activity in Germany and Austria harbours a very low risk of WNV infection.