Avian Influenza virus in sympatric wintering aquatic birds: rubbish dumps as hotspots for surveillance?

Trabajo Fin de Máster: Master en investigación Básica y Aplicada en Recursos Cinegéticos.The circulation of Avian Influenza viruses (AIV) in wild birds has been intensively studied, due to their implication in the maintenance and spread of these viruses. Most of these studies have focused on natural aquatic environments, where birds aggregate and in which viral survival is enhanced. Nevertheless, other places such as rubbish dumps also lead to massive aggregation of wild birds, including some known AIV reservoirs. Particularly, during the winter months, Spanish rubbish dumps harbor a great number of wintering wild birds. This is the case in rubbish dumps in the province of Ciudad Real (community of Castilla-La Mancha, Spain), where these animals also visit the surrounding wetlands where AIV circulation had been detected in previous years. In this study we analyzed the prevalence of AIV genome excretion in sympatric species that use two rubbish dumps in Ciudad Real, during the wintering season 2014-2015 and determined temporal, spatial and species variation. We tested 1190 fresh fecal samples, cloacal and oral swabs for AIV genome excretion by real time-RT PCR for the AIV matrix gene. We found an overall prevalence of 0.6%, peaking in October, which coincides with the arrival of migratory wild birds to Spanish territories. A higher prevalence was detected in gulls, which are known AIV reservoirs in natural environments, followed by cattle egrets and white storks. The detection of AIV genome excretion in all studied species indicates that all might play a role in the epidemiology of these viruses. Our results indicate that AIV circulates in wild birds that visit the studied rubbish dumps, and, at least in gulls, probably continuously during the wintering season. This underlines the potential importance of developing surveillance tasks in these places, namely through collection of fresh feces, a cost-effective sampling method appropriate for large scale LPAIV surveillance in wild birds.Peer Reviewe