title: Serological evidence for Saint Louis encephalitis virus in free-ranging New World monkeys and horses within the upper Paraná River basin region, Southern Brazil.
abstract: BACKGROUND
  Saint Louis encephalitis virus (SLEV) primarily occurs in the Americas and produces disease predominantly in humans. This study investigated the serological presence of SLEV in nonhuman primates and horses from southern Brazil.
  
  
  METHODS
  From June 2004 to December 2005, sera from 133 monkeys (Alouatta caraya, n=43; Sapajus nigritus, n=64; Sapajus cay, n=26) trap-captured at the Paraná River basin region and 23 blood samples from farm horses were obtained and used for the serological detection of a panel of 19 arboviruses. All samples were analyzed in a hemagglutination inhibition (HI) assay; positive monkey samples were confirmed in a mouse neutralization test (MNT). Additionally, all blood samples were inoculated into C6/36 cell culture for viral isolation.
  
  
  RESULTS
  Positive seroreactivity was only observed for SLEV. A prevalence of SLEV antibodies in sera was detected in Alouatta caraya (11.6%; 5/43), Sapajus nigritus (12.5%; 8/64), and S. cay (30.8%; 8/26) monkeys with the HI assay. Of the monkeys, 2.3% (1/42) of A. caraya, 6.3% 94/64) of S. nigritus, and 15.4% (4/26) of S. cay were positive for SLEV in the MNT. Additionally, SLEV antibodies were detected by HI in 39.1% (9/23) of the horses evaluated in this study. Arboviruses were not isolated from any blood sample.
  
  
  CONCLUSIONS
  These results confirmed the presence of SLEV in nonhuman primates and horses from southern Brazil. These findings most likely represent the first detection of this virus in nonhuman primates beyond the Amazon region. The detection of SLEV in animals within a geographical region distant from the Amazon basin suggests that there may be widespread and undiagnosed dissemination of this disease in Brazil.
authors: Instituto Latino-Americano de Ciências da Vida e da Natureza (ILACVN), Universidade Federal da Integração Latino-Americana (UNILA), Foz do Iguaçu, PR, Brasil.
authors: Walfrido Kühl
authors: WK
authors: Svoboda
authors: Departamento de Arbovirologia e Febres Hemorrágicas, Instituto Evandro Chagas, Ananindeua, PA, Brazil.
authors: Lívia Carício
authors: LC
authors: Martins
authors: Instituto Chico Mendes de Conservação da Biodiversidade, Porto Velho, RO, Brasil.
authors: Luciano de Souza
authors: Lde S
authors: Malanski
authors: Escola de Medicina Veterinária, Universidade Norte do Paraná, Arapongas, PR, Brasil.
authors: Marcos Massaaki
authors: MM
authors: Shiozawa
authors: Escola de Medicina Veterinária, Universidade de Cuiabá, Cuiabá, MT.
authors: Kledir Anderson Hofstaetter
authors: KA
authors: Spohr
authors: Departamento de Clínica Veterinária, Universidade Estadual de Londrina, Londrina, PR, Basil.
authors: Carmen Lúcia Scortecci
authors: CL
authors: Hilst
authors: Universidade Federal da Integração Latino-Americana, Foz do Iguaçu, PR.
authors: Lucas M
authors: LM
authors: Aguiar
authors: Centro Nacional de Pesquisa e Conservação de Primatas Brasileiros, Instituto Chico Mendes de Conservação da Biodiversidade, João Pessoa, PB.
authors: Gabriela
authors: G
authors: Ludwig
authors: Departamento de Zoologia, Universidade Federal do Paraná, Curitiba, PR, Brasil.
authors: Fernando de Camargo
authors: Fde C
authors: Passos
authors: Curitiba, Curitiba, PR, Brasil.
authors: Lineu Roberto da
authors: LR
authors: Silva
authors: Departamento de Medicina Veterinária Preventiva, Universidade Estadual de Londrina, Londrina, PR, Basil.
authors: Selwyn Arlington
authors: SA
authors: Headley
authors: Departamento de Medicina Veterinária Preventiva, Universidade Estadual de Londrina, Londrina, PR, Basil.
authors: Italmar Teodorico
authors: IT
authors: Navarro
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001938:Brazil / Q000453:epidemiology; D004665:Encephalitis Virus, St. Louis / Q000276:immunology*; D004674:Encephalitis, St. Louis / Q000175:diagnosis / Q000453:epidemiology / Q000662:veterinary*; D006385:Hemagglutination Inhibition Tests / Q000662:veterinary; D006734:Horse Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000821:virology; D006736:Horses; D051379:Mice; D008992:Monkey Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000821:virology; D051078:Platyrrhini; D015995:Prevalence
chemical_list: D000914:Antibodies, Viral