Birds as a risk factor for arboviruses in Buenos Aires Province

Abstract

St. Louis Encephalitis and West Nile viruses are arboviruses maintained in an enzootic cycle among birds by mosquitoes of the genus Culex. Both diseases have been reported in humans and evidence of infection have been identified in birds and horses in temperate Argentina. To advance in risk estimation, a bibliographic review of all published works in the country was carried out in order to know the potential host (only antibodies) and competent (able to amplify the virus) bird species. Then, the geographic distribution of bird species involved in their transmission cycles was characterized in Buenos Aires Province at two spatial scales: coarse grain potential host bird species occurrence maps for each virus (input Aves Argentinas), and fine grain density and percentage maps for each competent species (input eBird). The number of potential host bird species was higher in the northeast and southwest of the province for both viruses. Fine grain maps showed similar distribution and density patterns for all competent species, with maximums in the northeast and southeast, being Eared Dove the species with the highest density and percentage of sightings. Human cases records generally matched with high values areas in coarse grain maps and with high percentage cells in Eared Dove and House Sparrow fine grain maps. These results are a novel input for the elaboration of transmission risk maps and vigilance of these arbovirosis.