Review on Infections of the Central Nervous System by St. Louis Encephalitis, Rocio and West Nile Flaviviruses in Brazil, 2004-2014

Abstract

Rocio (ROCV), Saint Louis encephalitis (SLEV) and West Nile (WNV) are Flavivirus (Flaviviridae) probably carried by birds and transmitted by Culex mosquitoes. We show here a review on infections of the central nervous system by St. Louis Encephalitis, Rocio and West Nile Flaviviruses in Brazil, 2004-2014. In the last 10 years, serologic surveys in horses showed high proportions of seropositive animals which point out that SLEV and ROCV have circulated infecting horses in westcentral, southeast and other regions of Brazil and that WNV has been introduced into Brazil and circulates mostly in Pantanal region. However humans infected by WNV have not been reported. In the State of São Paulo: SLEV was isolated from a case clinically diagnosed as dengue in 2004; in 2006, 6 SLEV patients including 3 cases of menigoencephalitis were reported in the middle of a large epidemic of dengue type 3; and in 2008, 1 patient with acute febrile illness that was IgMpositive for dengue was found infected by SLEV by detection of the virus genome. In 2010, ROCV genome was detected in the cerebrospinal fluids of 2 patients from the northern region with meningoenchephalitis and also AIDS. This was the first report of infections by ROCV in the last 34 years and curiously, it occured more than 2000 km from where the virus was firstly found. It is necessary to improve the surveillance of SLEV, ROCV and WNV in Brazil.

West Nile Virus Encephalitis: The First Human Case Recorded in Brazil

“…Also, the countryside of Piauí State is located far from the regions where equine seropositivity has been detected. 2,4 However, a regional program of surveillance of human acute viral encephalitis had already begun when the patient was admitted. A protocol for investigation of encephalitis was applied, covering herpes virus, enteroviruses, and arboviruses.…”

“…E-mail: macsvieira@superig.com.br several other viral infections of the central nervous system, and 3) the limitations in the availability of diagnostic resources in most Brazilian hospitals. 2,4,[11][12][13] Since the detection of this first human case of WNV encephalitis in Brazil, strategies for a prospective approach to new cases are being implemented. Preliminary serologic studies performed among chickens and equines on the patient's farm showed the presence of specific antibodies against WNV confirmed by PRNT 90 .…”

“…Following the route of its spread southward from the United States, evidence of WNV circulation among animals has been detected in the Cayman Islands The reasons for the discrepancy between the serologic evidence of widespread WNV circulation and the absence of significant human or animal morbidity in the Americas, except the United States and Canada, are still a subject of debate. [1][2][3][4] Here we report the first documented case of West Nile encephalitis in Brazil.…”

Testing the link between perceived and actual risk of predation: mosquito oviposition site selection and egg predation by native and introduced fish

“…), Filariasis (Bernhard, Bernhard & Magnussen ), Japanese encephalitis (Kim et al . ), St. Louis encephalitis (de Figueiredo & Figueiredo ) and Avian malaria (Loiseau et al . ).…”

A reemergência do vírus Rocio no Brasil

“…Embora essas células apresentem importante papel antiviral através da produção de fatores como TGF-ß, elas se mostraram relativamente permissivas à infecção e replicação do ROCV. 3 Outros estudos também demonstraram que o eixo CCR5/MIP-1 α contribui para a intensa migração de células inflamatórias para o cérebro, o que está intimamente associado com a patogênese do ROCV. 2 Finalmente, há evidência recente de infecção ROCV generalizada entre cavalos no Brasil.…”