Seroprevalence of Flavivirus in horses in Chaco, Argentina. Circulation during 2013-2014

Abstract

Flaviviruses are responsible for several emerging mosquito-borne diseases in Argentina and in the Americas. Some of these diseases are zoonosis and were detected in recent years: West Nile virus (WNV) and Saint Louis encephalitis virus (SLEV) among them. WNV originated in Africa was detected for the first time in America in 1999 and it was first isolated from diseased and dead horses in 2006 in Argentina. Neutralizing antibodies from wild birds, humans and horses have been also detected in later years. SLEV re-emerged as a human pathogen in Argentina with the first epidemic in 2005. During this outbreak, viral strains were isolated from Culex mosquitoes and several studies have detected neutralizing antibodies from birds, human and horses, in the last ten years.The aim of this work is to provide information on the activity of the Flavivirus SLEV and WNV, identifying the infection in horses in three localities of the province of Chaco. From May 2013 to May 2014, serological surveys from 68 asymptomatic horses were conducted. Antibodies against SLEV (25 %) and WNV (8.82%) were detected. This is the first report of WNV circulation in equines from Chaco province and circulation of both viruses during the study period was demonstrated.