Serological Evidence of Exposure to Saint Louis Encephalitis and West Nile Viruses in Horses of Rio de Janeiro, Brazil

Infections with arboviruses are reported worldwide. Saint Louis encephalitis (SLEV) and West Nile viruses (WNV) are closely related flaviviruses affecting humans and animals. SLEV has been sporadically detected in humans, and corresponding antibodies have been frequently detected in horses throughout Brazil. WNV was first reported in western Brazil over a decade ago, has been associated with neurological disorders in humans and equines and its prevalence is increasing nationwide. Herein, we investigated by molecular and serological methods the presence or evidence of SLEV and WNV in equines from Rio de Janeiro. A total of 435 serum samples were collected from healthy horses and tested for specific neutralizing antibodies by plaque reduction neutralization test (PRNT90). Additionally, serum and central nervous system samples from 72 horses, including horses with neurological disorders resulting in a fatal outcome or horses which had contact with them, were tested by real-time reverse transcription–polymerase chain reaction (RT-qPCR) for both viruses. Adopting the criterion of four-fold antibody titer difference, 89 (20.4%) horses presented neutralizing antibodies for SLEV and five (1.1%) for WNV. No evidence of SLEV and WNV infection was detected by RT-qPCR and, thus, such infection could not be confirmed in the additional samples. Our findings indicate that horses from Rio de Janeiro were exposed to both SLEV and WNV, contributing to the current knowledge on the distribution of these viruses flaviviruses in Brazil.

[1]  L. Alcântara,et al.  Retrospective Investigation in Horses with Encephalitis Reveals Unnoticed Circulation of West Nile Virus in Brazil , 2022, Viruses.

[2]  Hellen Gomes Fernandes,et al.  ARBOVIROSES , 2021, Condutas clínicas em atenção primária à saúde.

[3]  A. Mondini,et al.  Detection of Saint Louis encephalitis virus in two Brazilian states , 2021, Journal of medical virology.

[4]  C. Canal,et al.  Serologic evidence of West Nile virus and Saint Louis encephalitis virus in horses from Southern Brazil , 2021, Brazilian Journal of Microbiology.

[5]  R. Souza-Santos,et al.  Zika, dengue and chikungunya population prevalence in Rio de Janeiro city, Brazil, and the importance of seroprevalence studies to estimate the real number of infected individuals , 2020, PloS one.

[6]  B. D. da Fonseca,et al.  Evidence for current circulation of an ancient West Nile virus strain (NY99) in Brazil , 2020, bioRxiv.

[7]  M. N. Rocha,et al.  Epidemiological surveillance of West Nile virus in the world and Brazil , 2020, Brazilian Journal of Veterinary Research and Animal Science.

[8]  E. Kroon,et al.  Silent Circulation of the Saint Louis Encephalitis Virus among Humans and Equids, Southeast Brazil , 2019, Viruses.

[9]  S. F. Aguiar,et al.  Yellow Fever Virus Reemergence and Spread in Southeast Brazil, 2016–2019 , 2019, Journal of Virology.

[10]  L. Castro-Jorge,et al.  West Nile virus infections are here! Are we prepared to face another flavivirus epidemic? , 2019, Revista da Sociedade Brasileira de Medicina Tropical.

[11]  B. Durand,et al.  Serological evidence of infection with dengue and Zika viruses in horses on French Pacific Islands , 2019, PLoS neglected tropical diseases.

[12]  J. Cardoso,et al.  First isolation of West Nile virus in Brazil , 2019, Memorias do Instituto Oswaldo Cruz.

[13]  G. C. F. Galinari,et al.  West Nile virus associated with equid encephalitis in Brazil, 2018 , 2018, Transboundary and emerging diseases.

[14]  L. Coffey,et al.  Reemergence of St. Louis Encephalitis Virus in the Americas , 2018, Emerging infectious diseases.

[15]  E. Gould,et al.  ICTV Virus Taxonomy Profile: Flaviviridae , 2017, The Journal of general virology.

[16]  Flávia Lowen Levy Chalhoub Investigação da circulação dos vírus da encefalite de Saint Louis e do oeste do Nilo em equinos do estado do Rio de Janeiro , 2017 .

[17]  R. Vorou Zika virus, vectors, reservoirs, amplifying hosts, and their potential to spread worldwide: what we know and what we should investigate urgently. , 2016, International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases.

[18]  T. N. Lima-Camara,et al.  Emerging arboviruses and public health challenges in Brazil , 2016, Revista de saude publica.

[19]  D. Valle,et al.  [Zika, dengue and chikungunya: challenges and issues]. , 2016, Epidemiologia e servicos de saude : revista do Sistema Unico de Saude do Brasil.

[20]  C. Saegerman,et al.  Clinical Sentinel Surveillance of Equine West Nile Fever, Spain. , 2016, Transboundary and emerging diseases.

[21]  R. S. Azevedo,et al.  West Nile Virus Encephalitis: The First Human Case Recorded in Brazil. , 2015, The American journal of tropical medicine and hygiene.

[22]  Andriyan Grinev,et al.  The Global Ecology and Epidemiology of West Nile Virus , 2015, BioMed research international.

[23]  R. Nogueira,et al.  Neutralising antibodies for Mayaro virus in Pantanal, Brazil , 2015, Memorias do Instituto Oswaldo Cruz.

[24]  E. Gould,et al.  Factors responsible for the emergence of arboviruses; strategies, challenges and limitations for their control , 2015, Emerging Microbes & Infections.

[25]  R. Z. Machado,et al.  A Saint Louis encephalitis and Rocio virus serosurvey in Brazilian horses. , 2014, Revista da Sociedade Brasileira de Medicina Tropical.

[26]  R. Nogueira,et al.  Serological Evidence of Widespread Circulation of West Nile Virus and Other Flaviviruses in Equines of the Pantanal, Brazil , 2014, PLoS neglected tropical diseases.

[27]  F. G. Gury Dohmen,et al.  [Molecular detection of Saint Louis encephalitis virus in mosquitoes in Buenos Aires]. , 2014, Medicina.

[28]  R. Lanciotti,et al.  West Nile virus surveillance, Brazil, 2008-2010. , 2013, Transactions of the Royal Society of Tropical Medicine and Hygiene.

[29]  R. Z. Machado,et al.  Serologic survey of West Nile virus in horses from Central-West, Northeast and Southeast Brazil , 2013, Memorias do Instituto Oswaldo Cruz.

[30]  M. Teixeira,et al.  Isolation of Saint Louis Encephalitis Virus from a Horse with Neurological Disease in Brazil , 2013, PLoS neglected tropical diseases.

[31]  A. Brault,et al.  Ilheus Virus Isolation in the Pantanal, West-Central Brazil , 2013, PLoS neglected tropical diseases.

[32]  M. Müller,et al.  Provenance and Geographic Spread of St. Louis Encephalitis Virus , 2013, mBio.

[33]  I. Bosch,et al.  Serological detection of West Nile virus in horses and chicken from Pantanal, Brazil. , 2012, Memorias do Instituto Oswaldo Cruz.

[34]  Mário Luís Pessôa Guedes CULICIDAE (DIPTERA) NO BRASIL: RELAÇÕES ENTRE DIVERSIDADE, DISTRIBUIÇÃO E ENFERMIDADES. , 2012 .

[35]  M. Ribeiro,et al.  Spatial distribution of arboviral mosquito vectors (Diptera, Culicidae) in Vale do Ribeira in the South-eastern Brazilian Atlantic Forest. , 2012, Cadernos de saude publica.

[36]  R. S. Neto,et al.  Analysis of socioeconomic and environmental constraints to implement forestry in the Northern and Northwestern areas of Rio de Janeiro State , 2012 .

[37]  H. Schatzmayr,et al.  Neutralising antibodies for West Nile virus in horses from Brazilian Pantanal. , 2011, Memorias do Instituto Oswaldo Cruz.

[38]  A. Mondini,et al.  Detection of Saint Louis encephalitis virus in dengue-suspected cases during a dengue 3 outbreak. , 2011, Vector borne and zoonotic diseases.

[39]  M. Nogueira,et al.  Serologic evidence of the recent circulation of Saint Louis encephalitis virus and high prevalence of equine encephalitis viruses in horses in the Nhecolândia sub-region in South Pantanal, Central-West Brazil. , 2010, Memorias do Instituto Oswaldo Cruz.

[40]  R. T. Vianna Inquéritos soroepidemiológicos em eqüinos da região Sul do Brasil para detecção de anticorpos anti-flavivírus de interesse em saúde pública , 2010 .

[41]  G. Dobler,et al.  Emergence of zoonotic arboviruses by animal trade and migration , 2010, Parasites & Vectors.

[42]  L. C. Martins,et al.  Epidemiology of Saint Louis encephalitis virus in the Brazilian Amazon region and in the State of Mato Grosso do Sul, Brazil: elevated prevalence of antibodies in horses , 2010 .

[43]  S. Weaver,et al.  Present and future arboviral threats. , 2010, Antiviral research.

[44]  E. Hayes,et al.  West Nile virus in the Americas. , 2008, The Medical clinics of North America.

[45]  A. Barrett,et al.  Guidelines for Plaque-Reduction Neutralization Testing of Human Antibodies to Dengue Viruses. , 2008, Viral immunology.

[46]  A. Mondini,et al.  Simultaneous infection by DENV-3 and SLEV in Brazil. , 2007, Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology.

[47]  L. Figueiredo,et al.  Emergent arboviruses in Brazil. , 2007, Revista da Sociedade Brasileira de Medicina Tropical.

[48]  R. Souza,et al.  St. Louis encephalitis virus: first isolation from a human in São Paulo State, Brazil. , 2005, Revista do Instituto de Medicina Tropical de Sao Paulo.

[49]  A. Barrett,et al.  Transmission cycles, host range, evolution and emergence of arboviral disease , 2004, Nature Reviews Microbiology.

[50]  R. Hall,et al.  Epitope-Blocking Enzyme-Linked Immunosorbent Assays for Detection of West Nile Virus Antibodies in Domestic Mammals , 2003, Journal of Clinical Microbiology.

[51]  N. Komar West Nile virus: epidemiology and ecology in North America. , 2003, Advances in virus research.

[52]  N. Komar West Nile Virus Surveillance using Sentinel Birds , 2001, Annals of the New York Academy of Sciences.

[53]  R. Lanciotti,et al.  Nucleic Acid Sequence-Based Amplification Assays for Rapid Detection of West Nile and St. Louis Encephalitis Viruses , 2001, Journal of Clinical Microbiology.

[54]  L. Figueiredo The Brazilian flaviviruses. , 2000, Microbes and infection.

[55]  J. Roehrig,et al.  Rapid Detection of West Nile Virus from Human Clinical Specimens, Field-Collected Mosquitoes, and Avian Samples by a TaqMan Reverse Transcriptase-PCR Assay , 2000, Journal of Clinical Microbiology.

[56]  J. Rappole,et al.  Migratory birds and spread of West Nile virus in the Western Hemisphere. , 2000, Emerging infectious diseases.

[57]  N. S. Romano-Lieber,et al.  [Serological survey on arbovirus infection in residents of an ecological reserve]. , 2000, Revista de saude publica.

[58]  H. Schatzmayr,et al.  An outbreak of dengue virus at Rio de Janeiro--1986. , 1986, Memorias do Instituto Oswaldo Cruz.

[59]  S. Inouye,et al.  “Original Antigenic Sin” Phenomenon in Experimental Flavivirus Infections of Guinea Pigs: Studies by Enzyme‐Linked Immunosorbent Assay , 1984, Microbiology and immunology.

[60]  J. Leduc,et al.  Isolation of St. Louis encephalitis virus from a patient in Belém, Brazil. , 1981, The American journal of tropical medicine and hygiene.

[61]  L. E. Pereira,et al.  Isolation of St. Louis encephalitis virus in South Brazil. , 1979, The American journal of tropical medicine and hygiene.

[62]  H. Schatzmayr,et al.  Arbovirus antibodies in children of rural Guanabara, Brazil. , 1975, Intervirology.

[63]  L. Jeffcott Some practical aspects of the transfer of passive immunity to newborn foals. , 1974, Equine veterinary journal.

[64]  D. Francy,et al.  Isolation of St. Louis encephalitis and Cache Valley viruses from Saskatchewan mosquitoes. , 1973, Canadian journal of public health = Revue canadienne de sante publique.

[65]  R. Shope,et al.  ISOLATION OF ST. LOUIS ENCEPHALITIS VIRUS FROM ARTHROPODS IN PAR'A, BRAZIL. , 1964, The American journal of tropical medicine and hygiene.

[66]  L. Lumsden St. Louis encephalitis in 1933; observations on epidemiological features. , 1958, Public health reports.

[67]  J. Casals Viruses: the versatile parasites; the arthropod-borne group of animal viruses. , 1957, Transactions of the New York Academy of Sciences.

[68]  R. Blattner,et al.  Isolation of St. Louis encephalitis virus from the peripheral blood of a human subject. , 1946, The Journal of pediatrics.

[69]  L. T. Webster,et al.  A VIRUS ENCOUNTERED IN THE STUDY OF MATERIAL FROM CASES OF ENCEPHALITIS N THE ST. LOUIS AND KANSAS CITY EPIDEMICS OF 1933. , 1933, Science.