Identification of West Nile virus infection by anti-premembrane antibodies in Nicaraguan children prior to 2007–2009

Since its arrival to North America in 1999, West Nile virus (WNV) has caused multiple outbreaks in birds and humans, with thousands of human cases in the USA and Canada, whereas in Latin America, WNV has mainly been detected in birds and horses with few human cases. Due to cross-reactivity of anti-envelope antibodies among different flaviviruses, detection of WNV infection by serology to explore its epidemiology in Latin America remains a challenge. Previously, we reported that anti-premembrane antibodies can discriminate four flavivirus infections using Western blot analysis. Based on anti-WNV premembrane antibodies and confirmation by neutralization test, we report three Nicaraguan children with WNV infection, corresponding to a seropositive rate of 7.5%. Our findings underscore the transmission of WNV in humans in Central America and the application of improved seroepidemiological tools to address the knowledge gaps on the prevalence and distribution of WNV in Latin America and the Western Hemisphere.