Stable enzootic transmission levels of West Nile virus in free ranging birds from rural and urban sites in the province of Cordoba

A.I. QUAGLIA; F.S. FLORES; M.S. CONTIGIANI; L.A. DIAZ

Buenos Aires

Congreso; X International Equine Infectious Diseases Conference; 2016

West Nile virus (WNV) became an important arbovirus pathogen for equines for the American continent since its introduction in 1999. However, a worldwide emergence as an equine pathogen is shows form last 5 years. In Argentina, first evidence of native circulation was registered in 2004 in birds and 2006 in equines. With the aim to corroborate the enzootic transmission of WNV inits potential avian hosts we survey avian sera collected in rural (Mar Chiquita lagoon) and urban (Cordoba city) areas of Cordoba province. Sera collections were carried out in both places during summer and fall in 2005 and 2012 (Mar Chiquita) and in 2005 and 2013 (Cordoba). WNV seroprevalence increased between years in Cordoba (2.6% [2005] vs. 3.3% [2013]) and Mar Chiquita (2.8[2005] vs. 3.7 [2012]). In Cordoba city 18 bird species were detected infected being the most seroprevalence Cattle Tyrant (Machetornis rixosus), Rufous Hornero (Furnarius rufus) and Creamy-bellied Thrush (Turdus amaurochalinus). On the other hand only 9 seropositive bird species were found in Mar Chiquita. Grassland Yellow-finch (Sicalis luteola), Picui ground dove (Columbina picui) and Rufous Hornero (Furnarius rufus) were the most found frequently infected. Our data suggest that WNV is actively transmitted in urban and rural areas in the central region of the province of Cordoba, using free ranging birds as potential amplifying hosts. The exotic West Nile virus was introduced inArgentina in 2004. Evidences support its wide dispersion and successful establishment in the north and central region of the country. However, neither massive bird mortality events nor equine and human epidemic events were reported. There is no evidence regarding this discrepancy with the United States. Further ecological and virological studies are needed to elucidatefactors influencing its epidemiological behavior.