We studied the molecular epidemiology of dengue virus type 3 (DENV-3) in Brazil and Paraguay by analyzing the 5' and 3' untranslated regions (5' and 3'UTRs) and the E protein gene of viruses isolated between 2002 and 2004. Both 5' and 3'UTRs were highly conserved. However, the 3'UTR of two isolates from Brazil contained eight nucleotide deletions compared with the remaining 26 viruses. Phylogenetic analyses suggested that DENV-3 was introduced into Brazil from the Caribbean Islands at least twice and into Paraguay from Brazil at least three times.

Guarana (Paullinia cupana var. sorbilis) is a plant native to the central Amazon basin. Roasted seed extracts have been used as medicinal beverages since pre-Colombian times, due to their reputation as stimulants, aphrodisiacs, tonics, as well as protectors of the gastrointestinal tract. Guarana plants are commercially cultivated exclusively in Brazil to supply the national carbonated soft-drink industry and natural product stores around the world. In this report, we describe and discuss the annotation of 15,387 ESTs from guarana seeded-fruits, highlighting sequences from the flavonoid and purine alkaloid pathways, and those related to biotic stress avoidance. This is the largest set of sequences registered for the Sapindaceae family.

Dengue type 3 genotype V viruses have been recently detected in Brazil and Colombia. In this study, we described another Brazilian isolate belonging to this genotype. Phylogenetic analysis including dengue type 3 viruses isolated worldwide showed that Brazilian and Colombian viruses were closely related to viruses isolated in Asia more than two decades ago. The characteristic evolutionary pattern of dengue type 3 virus cannot explain the close similarity of new circulating viruses with old viruses. Further studies are needed to confirm the origin of the new dengue type III genotype circulating in Brazil and Colombia.

The reintroduction of dengue virus type 3 (DENV-3) in Brazil in 2000 and its subsequent spread throughout the country was associated with genotype III viruses, the only DENV-3 genotype isolated in Brazil prior to 2002. We report here the co-circulation of two different DENV-3 genotypes in patients living in the Northern region of Brazil during the 2002-2004 epidemics. Complete genomic sequences of viral RNA were determined from these epidemics, and viruses belonging to genotypes V (Southeast Asia/South Pacific) and III were identified. This recent co-circulation of different DENV-3 genotypes in South America may have implications for pathological and epidemiological dynamics.Key words: dengue virus type 3 -genotype III and V -co-circulation -phylogenetic analysis -AmazonDengue is an emerging infectious disease affecting almost 50 million people in tropical and subtropical regions of the world. Dengue fever (DF) and dengue hemorrhagic fever (DHF) are caused by four closely related, but antigenically different dengue virus serotypes 1-4 (DENV-1-4) (Gubler & Clark 1995). Since the introduction of the DENV into Brazil in 1986, more than four million cases of dengue have been reported (Cordeiro et al. 2007), and the incidence of severe clinical symptoms has increased. No vaccine or specific therapeutic antiviral measures are available.Several studies have suggested that individuals experiencing a second dengue infection with a heterologous serotype are at greater risk for developing DHF or dengue shock syndrome (DSS) (Cummings et al. 2005, Halstead et al. 2005. However, DHF and DSS are also observed in primary cases, and not all secondary infections correspond to severe forms of the disease. Studies based on molecular epidemiology have provided evidence that differences in virulence between viral strains could play a role in the severity of the disease (Mangada & Igarashi 1998, Rico-Hesse 2003.Major dengue virus epidemics occurred in Brazil in 1986 and 1990, due to the introduction of DENV-1 and -2, respectively, and the subsequent spread of these serotypes throughout the country. DENV-3 reappeared in 1994 in Central America (Nicaragua and Panama) after 17 years of absence, and later spread to Mexico and the Caribbean (CDC 1995, Guzman et al. 1996, Usuku et al. 2001. In 2000, the presence of this serotype was re- PATIENTS, MATERIALS AND METHODSClinical samples and viruses -A serum sample from a dengue positive patient who had traveled to an area of epidemic dengue in RJ in Southeastern Brazil, and eight serum samples from patients living in Acre (AC) and RO in Northern Brazil (Table I, Fig. 1) were kindly provided by LACEN, Curitiba and IPEPATRO, Porto Velho, respectively. All patients were diagnosed with DF. These samples were used for the characterization of DENV genomes.RNA extraction and RT-PCR -Viral RNA was isolated from 140 μl of patient serum samples, taken during the acute phase of the disease and/or from 140 μl of purified virus prepared from cell culture supernatants after three passages in C6/36 cells, ...

Flavivirus is a genus of arthropod-transmitted viruses of the family Flaviviridae, and in Brazil, up to eleven different Flavivirus have been isolated. We collected blood from farmers in the municipality of Theobroma, which is located 320km from the City of Porto Velho, the former capital of the Brazilian State of Rondônia. For viral isolation, we used newborn mouse brain, followed by RT-PCR with specific universal Flavivirus primers. We obtained fragments 958bp and 800bp in length. Based on BLAST, these sequences were 91% similar to a sequence of Cacipacore virus.