INVESTIGAÇÃO SOROLÓGICA PARA AS ARBOVIROSES EM ÁREAS DE EXPLORAÇÃO MINERAL NO ESTADO DO PARÁ

Introdução: O estado do Pará vem sofrendo grandes transformações ambientais, dentre elas a exploração mineral e o desmatamento, o que aumenta o risco de infecção humana por arbovírus. Assim, objetiva-se demonstrar, através da presença de anticorpos IgM e IgG a possível circulação de arbovírus em residentes e trabalhadores oriundos dos municípios de Parauapebas, no período de 2021 a 2022. Métodos: Foram analisados 532 soros humanos pelo teste de Inibição da Hemaglutinação (IH) para 17 tipos diferentes de arbovírus (Eastern equine encephalitis otma, Western equine encephalitis otma, Mayaro otma, Mucambo otma, Chikungunya otma, Orthobunyavirus tacaiumaense, Orthoflavivirus nilense, Orthoflavivirus flavi cepa selvagem e cepa vacinal (17D), Orthoflavivirus denguei sorotipos 1, 2, 3 e 4, Orthoflavivirus zikaense, Orthoflavivirus louisense, Rocio otma, Orthoflavivirus ilheusense e Orthobunyavirus oropoucheense). A partir dos resultados obtido no teste de IH foram realizada a captura de IgM pelo método de ELISA (MAC-ELISA) em 89 amostras para Mayaro otma, 90 Chikungunya otma, 504 Orthoflavivirus denguei, 504 Orthoflavivirus nilense, 504 Orthoflavivirus louisense, 504 Orthoflavivirus zikaense e 51 Orthobunyavirus oropoucheense. Resultados: Dentre as 532 amostras testadas por IH, 513 (96,43%) apresentaram anticorpos totais. 511 (96,05%) foram positivas para Orthoflavivirus, 101 (18,98%) Alphavirus, 56 (10,53%) Orthobunyavirus. Reação simultânea foi observado em 138 (25,94%) amostras e anticorpos para FAV (vacinal- 17D) em 489 (91,92%). No MAC ELISA, 4 (0,79%) amostras foram positivas para Orthoflavivirus denguei, 1 (0,20%) Orthoflavivirus nilense, 2 (0,40%) Orthoflavivirus louisense, 1 (0,20%) Orthoflavivirus zikaense, 1 (1,96%) Orthobunyavirus oropoucheense. Assim como, 228 (10,15%) apresentaram detecção de anticorpos na zona borderline para uma das espécies testadas e 97 (4,32%) apresentaram reatividade cruzada entre Orthoflavivirus e Orthobunyavirus. Conclusão: Foi possível detectar infecção recente para Orthoflavivirus denguei, Orthoflavivirus zikaense, Orthoflavivirus nilense, Orthobunyavirus oropoucheense e Orthoflavivirus louisense, bem como foi observada a circulação dos demais arbovírus testados na área estudada. Medidas de prevenção das arboviroses e o controle vetorial são fundamentais para evitar surtos e epidemias dessas arboviroses

First isolation and genome sequence analysis of West Nile Virus in mosquitoes in Brazil

VALE S.A; Evandro Chagas Institute (IEC)Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Ananindeua, PA, Brasil.State University of Pará. Center of Biological and Health Sciences. Graduate Program in Parasitary Biology in the Amazon. Belém, PA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Adolfo Lutz Institute. Immunology Center. São Paulo, SP, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Setor de Zootecnia e Produção de Animais de Laboratório. Ananindeua, PA, Brasil.State University of Pará. Center of Biological and Health Sciences. Graduate Program in Parasitary Biology in the Amazon. Belém, PA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Ananindeua, PA, Brasil.West Nile virus is a flavivirus transmitted by mosquitoes, mainly of the genus Culex. In Brazil, serological studies have already indicated the circulation of the virus since 2003, with the first human case detected in 2014. The objective of the present paper is to report the first isolation of WNV in a Culex (Melanoconion) mosquito. Arthropods were collected by protected human attraction and CDC light bait, and taxonomically identified and analyzed by viral isolation, complement fixation and genomic sequencing tests. WNV was isolated from samples of Culex (Melanoconion) mosquitoes, and the sequencing analysis demonstrated that the isolated strain belonged to lineage 1a. The finding of the present study presents the first evidence of the isolation and genome sequencing of WNV in arthropods in Brazil

Clinical and serological tests for arboviruses in free-living domestic pigeons (Columba livia)

To Fapespa, for granting a Master’s scholarship, to PNMG, for capture of the birds, to the Microbiology and Immunology Laboratory of the UFRA, for collection of the samples, and to the SAARB/IEC, for their support in the development of serological tests.Universidade Federal do Pará. Instituto de Ciências Biológicas. Belém, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Parque Naturalístico Mangal das Garças. Setor Veterinário. Belém, PA, Brasil.Universidade Federal do Pará. Instituto de Ciências Biológicas. Belém, PA, Brasil.Universidade Federal Rural da Amazônia. Instituto da Saúde e Produção Animal. Laboratório de Biologia Molecular. Belém, PA, Brasil.Universidade Federal Rural da Amazônia. Instituto da Saúde e Produção Animal. Laboratório de Biologia Molecular. Belém, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Universidade Federal Rural da Amazônia. Instituto da Saúde e Produção Animal. Laboratório de Biologia Molecular. Belém, PA, Brasil.BACKGROUND: In this study, we evaluated the role of free-living domestic pigeons (Columba livia) as a reservoir of arboviruses in the city of Belém, state of Pará, Brazil. We investigated the presence of antibodies against the most prevalent arboviruses. OBJECTIVES: This study was aimed at evaluating some clinical and physical parameters of domestic pigeons, including the presence of antibodies to Amazon-endemic arboviruses. METHODS: Eighty-five healthy pigeons were captured in Mangal das Garças Park, in Belém, and were bled. Upon capture, the birds were subjected to a clinical examination in search of alterations that could indicate the presence of arboviruses. Blood samples were converted to serum and tested using the haemagglutination inhibition (HI) technique with a panel of 19 antigens of arboviruses circulating in the Amazon. The confirmation assay for the positive reactions to the viral species tested by HI was a neutralisation test in new-born Swiss albino mice (Mus musculus) [mouse neutralisation test (MNT)]. FINDINGS: A total of 10 (11.8%) serum samples tested positive for antiflavivirus antibodies by HI. All the samples positive for the HI test were subjected to MNT for detection of viruses and yielded negative results (logarithmic neutralisation index < 1.7). MAIN CONCLUSION: The results represent the first serological detection of antiarbovirus antibodies in domestic pigeons as potential hosts of arboviruses in Brazil. The detection of haemagglutination-inhibiting antibodies against genus Flavivirus indicated that there was recent contact between the analysed domestic pigeons and these arboviruses. Further studies are needed to evaluate the role of free-living pigeons in the maintenance cycle and spread of arboviruses in the Amazon

Serological and molecular evidence of the circulation of the venezuelan equine encephalitis virus subtype IIIA in humans, wild vertebrates and mosquitos in the Brazilian Amazon

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), MCTI/CNPq/FNDCT—Ação Transversal n68/2013 Programa de Grande Escala da Biosfera-Atmosfera na Amazônia (Process 457664/2013-4) to PFCV and Instituto Evandro Chagas SVS/MS. PFCV is also a fellow of the CNPqMinistério da Saúde. Secretaria de Ciência, Tecnologia, Inovação e Insumos Estratégicos. Instituto Evandro Chagas. Ananindeua, PA, Brasil / Ministério da Saúde. Secretaria de Ciência, Tecnologia, Inovação e Insumos Estratégicos. Instituto Evandro Chagas. Programa de Pós-Graduação em Virologia. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Ciência, Tecnologia, Inovação e Insumos Estratégicos. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Ciência, Tecnologia, Inovação e Insumos Estratégicos. Instituto Evandro Chagas. Ananindeua, PA, BrasilMinistério da Saúde. Secretaria de Ciência, Tecnologia, Inovação e Insumos Estratégicos. Instituto Evandro Chagas. Ananindeua, PA, BrasilMinistério da Saúde. Secretaria de Ciência, Tecnologia, Inovação e Insumos Estratégicos. Instituto Evandro Chagas. Ananindeua, PA, BrasilMinistério da Saúde. Secretaria de Ciência, Tecnologia, Inovação e Insumos Estratégicos. Instituto Evandro Chagas. Ananindeua, PA, BrasilMinistério da Saúde. Secretaria de Ciência, Tecnologia, Inovação e Insumos Estratégicos. Instituto Evandro Chagas. Ananindeua, PA, BrasilMinistério da Saúde. Secretaria de Ciência, Tecnologia, Inovação e Insumos Estratégicos. Instituto Evandro Chagas. Ananindeua, PA, BrasilMinistério da Saúde. Secretaria de Ciência, Tecnologia, Inovação e Insumos Estratégicos. Instituto Evandro Chagas. Ananindeua, PA, BrasilMinistério da Saúde. Secretaria de Ciência, Tecnologia, Inovação e Insumos Estratégicos. Instituto Evandro Chagas. Ananindeua, PA, BrasilMinistério da Saúde. Secretaria de Ciência, Tecnologia, Inovação e Insumos Estratégicos. Instituto Evandro Chagas. Ananindeua, PA, BrasilMinistério da Saúde. Secretaria de Ciência, Tecnologia, Inovação e Insumos Estratégicos. Instituto Evandro Chagas. Ananindeua, PA, BrasilMinistério da Saúde. Secretaria de Ciência, Tecnologia, Inovação e Insumos Estratégicos. Instituto Evandro Chagas. Ananindeua, PA, BrasilMinistério da Saúde. Secretaria de Ciência, Tecnologia, Inovação e Insumos Estratégicos. Instituto Evandro Chagas. Ananindeua, PA, Brasil / Pará State University. Department of Pathology. Belém, PA, Brazil.Ministério da Saúde. Secretaria de Ciência, Tecnologia, Inovação e Insumos Estratégicos. Instituto Evandro Chagas. Ananindeua, PA, Brasil / Ministério da Saúde. Secretaria de Ciência, Tecnologia, Inovação e Insumos Estratégicos. Instituto Evandro Chagas. Programa de Pós-Graduação em Virologia. Ananindeua, PA, Brasil.Understanding the interaction between viruses and ecosystems in areas with or without anthropic interference can contribute to the organization of public health services, as well as prevention and disease control. An arbovirus survey was conducted at Caxiuanã National Forest, Pará, Brazil, where 632 local residents, 338 vertebrates and 15,774 pools of hematophagous arthropods were investigated. Neutralization antibodies of the Venezuelan Equine Encephalitis virus, subtype IIIA, Mucambo virus (MUCV) were detected in 57.3% and 61.5% of humans and wild vertebrates, respectively; in addition, genomic fragments of MUCV were detected in pool of Uranotaenia (Ura.) geometrica. The obtained data suggest an enzootic circulation of MUCV in the area. Understanding the circulation of endemic and neglected arboviruses, such as MUCV, represents an important health problem for the local residents and for the people living in the nearby urban centers

Arboviruses in Free-Ranging Birds and Hematophagous Arthropods (Diptera, Nematocera) from Forest Remnants and Urbanized Areas of an Environmental Protection Area in the Amazon Biome

The rapid and disorderly urbanization in the Amazon has resulted in the insertion of forest fragments into cities, causing the circulation of arboviruses, which can involve hematophagous arthropods and free-ranging birds in the transmission cycles in urban environments. This study aimed to evaluate the circulation of arboviruses in free-ranging birds and hematophagous arthropods captured in an Environmental Protection Area in the Belem metropolitan area, Brazil. Birds were captured using mist nets, and hematophagous arthropods were collected using a human protected attraction technique and light traps. The birds&rsquo; sera were subjected to a hemagglutination inhibition test to detect antibodies against 29 arbovirus antigens. Arthropod macerates were inoculated into C6/36 and VERO cell cultures to attempt viral isolation and were tested using indirect immunofluorescence, subsequent genetic sequencing and submitted for phylogenetic analysis. Four bird sera were positive for arbovirus, and one batch of Psorophora ferox was positive for Flavivirus on viral isolation and indirect immunofluorescence. In addition, the Ilheus virus was detected in the sequencing and phylogenetic analysis. The presence of antibodies in sera from free-ranging birds and the isolation of Ilheus virus in Psorophora ferox indicate the circulation of arboviruses in forest remnants in the urban center of Belem

Clinical and serological tests for arboviruses in free-living domestic pigeons (Columba livia)

BACKGROUND In this study, we evaluated the role of free-living domestic pigeons (Columba livia) as a reservoir of arboviruses in the city of Belém, state of Pará, Brazil. We investigated the presence of antibodies against the most prevalent arboviruses. OBJECTIVES This study was aimed at evaluating some clinical and physical parameters of domestic pigeons, including the presence of antibodies to Amazon-endemic arboviruses. METHODS Eighty-five healthy pigeons were captured in Mangal das Garças Park, in Belém, and were bled. Upon capture, the birds were subjected to a clinical examination in search of alterations that could indicate the presence of arboviruses. Blood samples were converted to serum and tested using the haemagglutination inhibition (HI) technique with a panel of 19 antigens of arboviruses circulating in the Amazon. The confirmation assay for the positive reactions to the viral species tested by HI was a neutralisation test in new-born Swiss albino mice (Mus musculus) [mouse neutralisation test (MNT)]. FINDINGS A total of 10 (11.8%) serum samples tested positive for antiflavivirus antibodies by HI. All the samples positive for the HI test were subjected to MNT for detection of viruses and yielded negative results (logarithmic neutralisation index < 1.7). MAIN CONCLUSION The results represent the first serological detection of antiarbovirus antibodies in domestic pigeons as potential hosts of arboviruses in Brazil. The detection of haemagglutination-inhibiting antibodies against genus Flavivirus indicated that there was recent contact between the analysed domestic pigeons and these arboviruses. Further studies are needed to evaluate the role of free-living pigeons in the maintenance cycle and spread of arboviruses in the Amazon

Isolation of Flaviviruses and Alphaviruses with encephalitogenic potential diagnosed by Evandro Chagas Institute (Pará, Brazil) in the period of 1954–2022: six decades of discoveries

Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Isolamento Viral. Ananindeua, PA, Brasil.Viruses with encephalitogenic potential can cause neurological conditions of clinical and epidemiological importance, such as Saint Louis encephalitis virus, Venezuelan equine encephalitis virus, Eastern equine encephalitis virus, Western equine encephalitis virus, Dengue virus, Zika virus, Chikungunya virus, Mayaro virus and West Nile virus. The objective of the present study was to determine the number of arboviruses with neuroinvasive potential isolated in Brazil that corresponds to the collection of viral samples belonging to the Department of Arbovirology and Hemorrhagic Fevers, Evandro Chagas Institute (SAARB/IEC) of the Laboratory Network of National Reference for Arbovirus Diagnosis from 1954 to 2022. In the analyzed period, a total of 1,347 arbovirus samples with encephalitogenic potential were isolated from mice; 5,065 human samples were isolated exclusively by cell culture; and 676 viruses were isolated from mosquitoes. The emergence of new arboviruses may be responsible for diseases still unknown to humans, making the Amazon region a hotspot for infectious diseases due to its fauna and flora species characteristics. The detection of circulating arboviruses with the potential to cause neuroinvasive diseases is constant, which justifies the continuation of active epidemiological surveillance work that offers adequate support to the public health system regarding the virological diagnosis of circulating arboviruses in Brazil

Isolation of Flaviviruses and Alphaviruses with Encephalitogenic Potential Diagnosed by Evandro Chagas Institute (Pará, Brazil) in the Period of 1954–2022: Six Decades of Discoveries

Viruses with encephalitogenic potential can cause neurological conditions of clinical and epidemiological importance, such as Saint Louis encephalitis virus, Venezuelan equine encephalitis virus, Eastern equine encephalitis virus, Western equine encephalitis virus, Dengue virus, Zika virus, Chikungunya virus, Mayaro virus and West Nile virus. The objective of the present study was to determine the number of arboviruses with neuroinvasive potential isolated in Brazil that corresponds to the collection of viral samples belonging to the Department of Arbovirology and Hemorrhagic Fevers, Evandro Chagas Institute (SAARB/IEC) of the Laboratory Network of National Reference for Arbovirus Diagnosis from 1954 to 2022. In the analyzed period, a total of 1,347 arbovirus samples with encephalitogenic potential were isolated from mice; 5,065 human samples were isolated exclusively by cell culture; and 676 viruses were isolated from mosquitoes. The emergence of new arboviruses may be responsible for diseases still unknown to humans, making the Amazon region a hotspot for infectious diseases due to its fauna and flora species characteristics. The detection of circulating arboviruses with the potential to cause neuroinvasive diseases is constant, which justifies the continuation of active epidemiological surveillance work that offers adequate support to the public health system regarding the virological diagnosis of circulating arboviruses in Brazil

West Nile Virus in the State of Ceará, Northeast Brazil

In June 2019, a horse with neurological disorder was diagnosed with West Nile virus (WNV) in Boa Viagem, a municipality in the state of Ceará, northeast Brazil. A multi-institutional task force coordinated by the Brazilian Ministry of Health was deployed to the area for case investigation. A total of 513 biological samples from 78 humans, 157 domestic animals and 278 free-ranging wild birds, as well as 853 adult mosquitoes of 22 species were tested for WNV by highly specific serological and/or molecular tests. No active circulation of WNV was detected in vertebrates or mosquitoes by molecular methods. Previous exposure to WNV was confirmed by seroconversion in domestic birds and by the detection of specific neutralizing antibodies in 44% (11/25) of equids, 20.9% (14/67) of domestic birds, 4.7% (13/278) of free-ranging wild birds, 2.6% (2/78) of humans, and 1.5% (1/65) of small ruminants. Results indicate that not only equines but also humans and different species of domestic animals and wild birds were locally exposed to WNV. The detection of neutralizing antibodies for WNV in free-ranging individuals of abundant passerine species suggests that birds commonly found in the region may have been involved as amplifying hosts in local transmission cycles of WNV