OBJECTIVE:

To investigate the potential role of resident and migratory wild birds in West Nile virus (WNV) epidemiology in the region of Brazil where the first human case of West Nile fever was recorded.

MATERIALS AND METHODS:

The study was performed across two time spans (2014 and 2015). A total of 688 birds, representing 38 species, were captured using mist nets. Serum samples of 103 birds of 27 captured species were analyzed using hemagglutination inhibition (HI) tests.

RESULTS:

Twenty-three specimens exhibited monotypic or heterotypic reactions to 12 of the 20 virus species screened. HI tests revealed monotypic reactions for WNV in five samples from Paroaria dominicana, Mimus saturninus (n = 3), and Myiarchus tyrannulus, and heterotypic cross-reaction in eight samples from Columbina minuta, Columbina squammata, Columbina talpacoti, Leptotila verreauxi, Piaya cayana, Pitangus sulphuratus, Turdus rufiventris, and Paroaria dominicana. Six samples with heterotypic reactions were further analyzed using plaque reduction neutralization tests (PRNT), resulting in three positives for WNV in non-migrant birds: Columbina talpacoti, Piaya cayana, and Turdus rufiventris.

CONCLUSION:

This study provides evidence of WNV in free-living Passeriformes in Brazil. The findings suggest that WNV dissemination may begin with migratory birds that share resting and foraging areas with resident or shorter-range migratory birds, thereby sustaining vector mosquito populations and maintaining a zoonotic risk to humans.