Molecular Epidemiology of Den-2 Virus In Brazil

Abstract

Dengue (DEN) viruses belong to the family Flaviviridae, genus Flavivirus, and occur as four antigenically related, but distinct serotypes designated DEN-1, 2, 3 and 4 (EG Westaway et al. 1985 Intervirology 24: 183-192). The viruses are characterized by a single strand of RNA associated with a core protein, in a nucleocapside surrounded by a lipid envelope. The genoma consist of a single open reading frame coding for core protein (C), precursor of the membrane protein (prM) and envelope (E) structural proteins, followed by the non structural proteins NS1, NS2a, NS2b, NS3, NS4a The genetic variation among DEN viruses has been demonstrated by numerous methods including oligonucleotides fingerprinting, restriction enzymes, primer extension sequencing and nucleotide sequences from different fragments of genoma (R

Complete nucleotide sequence analysis of a Brazilian dengue virus type 2 strain

“…These data corroborate the results previously obtained by the partial sequencing of different genomic fragments (Deubel et al 1993, RicoHesse et al 1997, Miagostovich et al 1998. A direct association between the introduction of Asian DEN-2 virus with severe disease in the Americas has been shown previously (Rico-Hesse et al 1997), and our results are consistent with this scenario.…”

Molecular epidemiology of type 1 and 2 dengue viruses in Brazil from 1988 to 2001

“…Subsequently, in 1986, the first outbreak of greater proportions caused by DEN-1 occurred in the met-and Alagoas classified them into the Asian/ American-Asian genotype (18). Similar results were also obtained by nucleotide sequence analysis of another E protein gene segment (nucleotides 85 to 282) of three DEN-2 samples isolated in Brazil in 1990 (7).…”

“…Rico-Hesse et al (16) analyzed two DEN-2 viruses isolated in Venezuela and Colombia some time around 1987, and concluded that they belonged to the Southeast Asian genotype. In Brazil, this genotype was probably introduced either at the same time or at some point during 1988, like in other areas of the Americas (6,8,16,18,20,38,40).…”

“…About 80% of notified dengue cases in the Americas occurred in Brazil, and in the last years more than 1 million cases have been reported in all five Brazilian geographic regions (17). In spite of the importance of dengue as a serious public health problem in Brazil, only a few dengue viruses isolated from endemic regions have been analyzed with respect to genomic variability (6,7,9,16,(18)(19)(20).…”

Dengue virus type 3 in Rio de Janeiro, Brazil

“…A total of 1,832,371 cases were reported, resulting from DEN-1 and/or DEN-2 epidemics, and occurred in 24 out of 26 states and the Federal District/Brasília (Ministry of Health, Brazil). Molecular analysis performed on genome fragments from DEN-1 and DEN-2 viruses identified the Caribbean and Jamaican genotypes, respectively, as the virus strains circulating in the country (Rico-Hesse 1990, Vorndam et al 1994, Miagostovich et al 1998). The Jamaica genotype introduction into the Americas resulted in both an increase in the severe forms of the disease and epidemics in which there were a significant number of DHF/DSS cases (Nogueira et al 1993, RicoHesse et al 1997 .…”