Serological evidence of widespread circulation of West Nile virus and other flaviviruses in equines of the Pantanal, Brazil.
Alex Pauvolid-Corr��a, Zilca Campos, Raquel Juliano, Jason Velez, Rita Maria Ribeiro Nogueira, Nicholas Komar
Author Information
Alex Pauvolid-Corr��a: Laborat��rio de Flaviv��rus, Instituto Oswaldo Cruz, Funda����o Oswaldo Cruz, Minist��rio da Sa��de, Pavilh��o Helio e Peggy Pereira, Rio de Janeiro, Rio de Janeiro, Brazil ; Arbovirus Diseases Branch, Centers for Disease Control and Prevention, Fort Collins, Colorado, United States of America ; Fulbright Visiting Researcher in Doctorate Sandwich Program at Centers for Disease Control and Prevention, Fort Collins, Colorado, United States of America.
Zilca Campos: Embrapa Pantanal, Minist��rio da Agricultura Pecu��ria e Abastecimento, Corumb��, Mato Grosso do Sul, Brazil.
Raquel Juliano: Embrapa Pantanal, Minist��rio da Agricultura Pecu��ria e Abastecimento, Corumb��, Mato Grosso do Sul, Brazil.
Jason Velez: Arbovirus Diseases Branch, Centers for Disease Control and Prevention, Fort Collins, Colorado, United States of America.
Rita Maria Ribeiro Nogueira: Laborat��rio de Flaviv��rus, Instituto Oswaldo Cruz, Funda����o Oswaldo Cruz, Minist��rio da Sa��de, Pavilh��o Helio e Peggy Pereira, Rio de Janeiro, Rio de Janeiro, Brazil.
Nicholas Komar: Arbovirus Diseases Branch, Centers for Disease Control and Prevention, Fort Collins, Colorado, United States of America.
A recent study reported neutralizing antibodies to West Nile virus (WNV) in horses from four ranches of southern Pantanal. To extend that study, a serosurvey for WNV and 11 Brazilian flaviviruses was conducted with 760 equines, 238 sheep and 61 caimans from 17 local cattle ranches. Among the tested equines, 32 were collected from a ranch where a neurologic disorder outbreak had been recently reported. The sera were initially screened by using a blocking ELISA and then titrated by 90% plaque-reduction neutralization test (PRNT90) for 12 flaviviruses. Employing the criterion of 4-fold greater titer, 78 (10.3%) equines were seropositive for Ilheus virus, 59 (7.8%) for Saint Louis encephalitis virus, 24 (3.2%) for WNV, two (0.3%) for Cacipacore virus and one (0.1%) for Rocio virus. No serological evidence was found linking the neurological disease that affected local equines to WNV. All caimans and sheep were negative by blocking ELISA for flaviviruses. There were no seropositive equines for Bussuquara, Iguape, Yellow fever and all four Dengue virus serotypes. The detection of WNV-seropositive equines in ten ranches and ILHV and SLEV-seropositive equines in fourteen ranches of two different sub-regions of Pantanal is strong evidence of widespread circulation of these flaviviruses in the region.
