Field Study: Searching for West Nile Virus in Cuba

West Nile virus has circulated in many countries in Latin America after 1999; however, no outbreaks have been reported and in most of them, the virus has not been isolated yet. In Cuba, its circulation was documented since 2005 but the isolation of the virus has not been succeeded. A field study was performed to isolate the virus from mosquitoes and to detect flavi virus and West Nile virus antibodies in humans and birds. The study was conducted 2 localities in La Sierpe municipality, Sancti Spíritus province where the first West Nile virus human cases were reported in 2006. Three hundred and four human sera samples, 391 adult birds (32 species) and 234 pools of mosquitoes (9 species) were collected from both localities. In human sera samples, 60% of them were positive to Dengue 2 and 0.65% was positive to West Nile virus. In birds, the 14.4% of terrestrial and 61% of aquatic birds had flavivirus antibodies; meanwhile 1.4% from terrestrial and 19.4% of aquatic were specific to West Nile virus. The most representative species of mosquitoes captured was Culex quinquefasciatus. West Nile virus was not isolated neither detected by molecular methods. However, some of these pools were positive by RT-PCR to flavivirus, suggesting the presence of an insect flavivirus.