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 zoonoses 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.

Haemovigilance survey and screening strategy for arthropod‐borne viruses in blood donors from Argentina

“…As stated, this is the first report of antibody seroprevalence against Flavivirus in blood donors using a biological assay such as PNRT. Since the close antigenic association between Flaviviruses generates a cross‐reactive immune response 11 and considering their overlapping distribution in the region, 2,5,7,8,23–25 which increases the likelihood of exposure to multiple viruses of the same genus, PNRT remains the only assay that allows differentiating serological cross‐reactivity that could impair a real estimate of the seroprevalence values. Seroprevalence of arboviruses in blood donors provides important information to estimate viral circulation in the general population and is essential for understanding the risk of transmission through blood transfusions and developing effective strategies to prevent transmission of these viruses.…”

Serological evidence of equine infectious anaemia, West Nile fever, surra and equine piroplasmosis in a herd of horses in northern Argentina

“…Although the number of field studies dedicated to the pathogens circulating in this province remains low, it may be noted that numerous vector-borne diseases have already been reported. These include equine infectious anaemia (EIA) (De la Sota et al, 2005), West Nile fever (WNF) (Oria et al, 2018), surra (Santa Cruz et al, 2013, equine piroplasmosis (Babesia equi) (Holman et al, 1998), Eastern equine encephalomyelitis (EEE), Venezuelan equine encephalitis (VEE) and Western equine encephalomyelitis (WEE) (Monath et al, 1985).…”

“…WNF was first detected in Argentina from diseased and dead horses in 2006 (Chancey et al, 2015) and, since then, its circulation has been reported in different provinces in Argentina, including Chaco (Oria et al, 2018). Given the abundance of Culicidae (vectors of WNF) and birds (hosts, natural reservoir) in this region (Campbell et al, 2002), there appears to be a major risk of this virus being transmitted to incidental dead-end hosts represented by horses (and potentially humans).…”