Molecular characterization of two rocio flavivirus strains isolated during the encephalitis epidemic in são paulo state, brazil and the development of a one-step rt-pcr assay for diagnosis

Abstract

SUMMARYRocio virus (ROCV) was responsible for an explosive encephalitis epidemic in the 1970s affecting about 1,000 residents of 20 coastland counties in São Paulo State, Brazil. ROCV was first isolated in 1975 from the cerebellum of a fatal human case of encephalitis. Clinical manifestations of the illness are similar to those described for St. Louis encephalitis. ROCV shows intense antigenic cross-reactivity with Japanese encephalitis complex (JEC) viruses, particularly with Ilheus (ILHV), St. Louis encephalitis, Murray Valley and West Nile viruses. In this study, we report a specific RT-PCR assay for ROCV diagnosis and the molecular characterization of the SPAn37630 and SPH37623 strains. Partial nucleotide sequences of NS5 and E genes determined from both strains were used in phylogenetic analysis. The results indicated that these strains are closely related to JEC viruses, but forming a distinct subclade together with ILHV, in accordance with results recently reported by MEDEIROS et al. (2007).

Management of acute viral encephalitis in Brazil

“…Rocio virus was related with an encephalitis epidemic in São Paulo in the 1970s with nearly 1,000 affected individuals [33]. The complete genomic characterization of this virus isolated from a fatal case was recently published [34].…”

Evaluation of two molecular methods for the detection of Yellow fever virus genome

“…Although RT-PCR assays are commonly employed for detection of several flaviviruses, including DENV, JEV, WNV and SLEV (Coimbra et al, 2008; Hull et al, 2008; Jeong et al, 2011; Lanciotti et al, 1992; Maher-Sturgess et al, 2008; Yeh et al, 2010), protocols for the detection of YFV are less well established. In this article, the development and validation of two molecular methods for detection of YFV are described and their utility with samples obtained from hamsters infected experimentally and infected humans is demonstrated.…”