OCORRÊNCIA DA FEBRE DO NILO EM EQUINOS NO BRASIL

West Nile Fever (WNF) is a zoonotic arbovirus caused by the West Nile Virus (WNV). It is a highly relevant topic in veterinary medicine in Brazil. It was first identified in Uganda in 1937 and the virus spread to Africa, Europe, the Middle East, Western Asia and Australia. In 1999, the virus reached the United States and has since spread throughout the Americas, becoming the arbovirus with the largest geographic distribution. The first signs of WNV in Brazil appeared in 1999, with positive results in birds and horses, with birds acting as sentinels for the disease. In 2014, the first human case was recorded in Piauí. As of 2018, cases in birds and horses have been confirmed in Espírito Santo. WNV, an RNA virus of the Flaviviridae family, is transmitted by the bite of mosquitoes of the Culex genus, and these mosquitoes become infected through infected birds during the viremic period. Birds are amplifying hosts and humans and horses are accidental hosts. In Brazil, climatic, environmental and socioeconomic characteristics contribute to the amplification of the virus. Diagnosis is made by demonstrating antiviral IgM by ELISA, or, post-mortem, with RT-PCR. Preventive measures involve the use of repellents and screens, in addition to the application of larvicides. In horses, the application of vaccines, although recommended, is not yet licensed in Brazil. This study analyzed the occurrence of West Nile Fever in horses in Brazil through a review of scientific articles. Searches were conducted in the Google Scholar, PUBMED and Scielo databases, published between 2004 and 2024. The research was supported by the following search criteria: “Nile Fever”, “equines” and “Brazil”, in Portuguese, and “West Nile Fever”, “horses” and “Brazil”, in English. It was found that horses are accidental or terminal hosts and, because it is little known, many times it is not reported or diagnosed, thus demonstrating the importance of further studies and dissemination of information about this disease.