First report of multiple lineages of dengue viruses type 1 in Rio de Janeiro, Brazil.

BACKGROUND: In Brazil dengue has been a major public health problem since DENV-1 introduction and spread in 1986. After a low or silent co-circulation, DENV-1 re-emerged in 2009 causing a major epidemic in the country in 2010 and 2011. In this study, the phylogeny of DENV-1 strains isolated in RJ after its first introduction in 1986 and after its emergence in 2009 and 2010 was performed in order to document possible evolutionary patterns or introductions in a re-emergent virus. FINDINGS: The analysis of the E gene sequences demonstrated that DENV-1 isolated during 2009/2010 still belong to genotype V (Americas/Africa) but grouping in a distinct clade (lineage II) of that represented by earlier DENV-1 (lineage I). However, strains isolated in 2011 grouped together forming another distinct clade (lineage III). CONCLUSIONS: The monitoring of DENV is important to observe the spread of potentially virulent strains as well to evaluate its impact over the population during an outbreak. Whether explosive epidemics reported in Brazil caused mainly by DENV-1 was due to lineage replacement, or due the population susceptibility to this serotype which has not circulated for almost a decade or even due to the occurrence of secondary infections in a hyperendemic country, is not clear. This is the first report of multiple lineages of DENV-1 detected in Brazil.

Recombinant polypeptide antigen-based immunoglobulin G enzyme-linked immunosorbent assay for serodiagnosis of dengue.

We have developed an indirect enzyme-linked immunosorbent assay for detection of anti-dengue virus (DENV) immunoglobulin G antibodies using four recombinant DENV envelope polypeptides as antigens, which demonstrated a sensitivity of 89.4% and a specificity of 93.3%. These easily produced antigens are a feasible, cost-effective alternative for generating reagents for dengue serological tests.

Adenoviruses associated with acute gastroenteritis in hospitalized and community children up to 5 years old in Rio de Janeiro and Salvador, Brazil.

Acute gastroenteritis is a major source of morbidity and mortality among young children in developed and developing countries. Human adenoviruses (HAdVs), and in particular species F, are related to childhood diarrhoea worldwide. This study presents the results obtained during an investigation of HAdVs causing acute gastroenteritis in children hospitalized in Rio de Janeiro, RJ, Brazil, from April 1996 to September 2003, as well as in children with diarrhoea living in the slums of Salvador, BA, Brazil, from October 2001 to September 2003. A total of 3060 stool samples was analysed by an enzyme immunoassay for rotavirus and adenovirus (EIARA) and 61 (2%) were found to be positive. HAdV presented with low prevalence throughout the year, with a slight but not significant increase in incidence in late summer and early autumn. Children up to 2 years of age were the most frequently affected (79% of all positive samples). All positive samples were analysed further by generic and species-specific HAdV PCR protocols, confirming 100% specificity of this rapid and inexpensive EIARA. Species F was the most prevalent (65%), despite the occurrence of species A (12%), C, D and co-infection F/D (5% each) and species B and co-infections F/A, F/C and B/D (2% each). In order to type the species F strains as HAdV-40 or -41, generic PCR and a HinfI restriction digest were performed. HAdV-40 and -41 were found to represent 62% (23/37) and 38% (14/37), respectively. These results demonstrated that a combination of generic and species-specific PCRs is useful and reliable for HAdV species and type identification directly from faecal specimens. The results confirmed the endemism of human adenoviruses, mainly species F, in children as aetiological agents of diarrhoea, although the limited sensitivity of EIARA as a screening method may have underestimated their prevalence.

Effect of corticosteroid on lung parenchyma remodeling at an early phase of acute lung injury.

In vivo (lung resistive and viscoelastic pressures and static elastance) and in vitro (tissue resistance, elastance, and hysteresivity) respiratory mechanics were analyzed 1 and 30 days after saline (control) or paraquat (P [10 and 25 mg/kg intraperitoneally]) injection in rats. Additionally, P10 and P25 were treated with methylprednisolone (2 mg/kg intravenously) at 1 or 6 hours after acute lung injury (ALI) induction. Collagen and elastic fibers were quantified. Lung resistive and viscoelastic pressures and static elastance were higher in P10 and P25 than in the control. Tissue elastance and resistance augmented from control to P10 (1 and 30 days) and P25. Hysteresivity increased in only P25. Methylprednisolone at 1 or 6 hours attenuated in vivo and in vitro mechanical changes in P25, whereas P10 parameters were similar to the control. Collagen increment was dose and time dependent. Elastic fibers increased in P25 and at 30 days in P10. Corticosteroid prevented collagen increment and avoided elastogenesis. In conclusion, methylprednisolone led to a complete maintenance of in vivo and in vitro respiratory mechanics in mild lesion, whereas it minimized the changes in tissue impedance and extracellular matrix in severe ALI. The beneficial effects of the early use of steroids in ALI remained unaltered at Day 30.

Molecular typing of dengue virus type 2 in Brazil

Strain typing is a critical tool for molecular epidemiological analysis and can provide important information about the spread of dengue viruses. Here, we performed a molecular characterization of DEN-2 viruses isolated in Brazil during 1990-2000 from geographically and temporally distinct areas in order to investigate the genetic distribution of this serotype circulating in the country. Restriction site-specific polymerase chain reaction (RSS)-PCR presented the same pattern for all 52 Brazilian samples, showing the circulation of just one DEN-2 variant. Phylogenetic analysis using progressive pairwise alignments from 240-nucleotide sequences of the E/NS1 junction in 15 isolates showed that they belong to genotype III (Jamaica genotype)