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Revista do Instituto de Medicina Tropical de São Paulo
On-line version ISSN 1678-9946
COIMBRA, Terezinha Lisieux Moraes et al. 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. Rev. Inst. Med. trop. S. Paulo [online]. 2008, vol.50, n.2, pp.89-94. ISSN 1678-9946. http://dx.doi.org/10.1590/S0036-46652008000200005.
Rocio 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).
Keywords : Rocio virus; RT-PCR; Phylogenetic analysis; Disease diagnosis.