West Nile virus in Ecuador

Several studies have been carried out to determine the presence and circulation of West Nile Virus (WNV) in several species that interact in important ecosystems of Ecuador, such as the Galapagos Islands, where presence and surveillance studies of WNV have been carried out in wild and migratory birds (2003) (2008 to 2010), penguins (2003 to 2004). Studies have also been carried out on birds from different locations in Guayaquil (2011), and on Jauneche horses (2007), but no virus has been demonstrated in any of them. Nevertheless, in the Abras de Mantequilla wetland, two studies were conducted in equines aged between 3 months to 12 years, all of them mixed race, male and female, with no previous vaccination history and with presence of symptoms only in the first study. In the two studies the serum analysis was performed by the ELISA technique (reactivity determination) and Plaque Reduction Neutralization Test (PRNT). In the first study, 8.12% (13/160) of reactivity was determined in 13 horses and 22.22% of reactivity in 2 of 9 people; and only 3.12% (5/160 horses) of the presence of IgM antibodies against WNV. In relation to the second study, 12.6% (52/412) reactivity and 10.4% (43/412 horses) confirmed the serological evidence of WNV, with a final prevalence of 6.76%. Consequently, the WNV is present and circulating in the equines of the Ecuadorian coastal zone, which is a potential risk to the public health, nevertheless there is no updated information on investigations conducted in this regard.