150 research outputs found

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

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    <p>Abstract</p> <p>Background</p> <p>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.</p> <p>Findings</p> <p>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).</p> <p>Conclusions</p> <p>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.</p

    Gestational malaria associated to Plasmodium vivax and Plasmodium falciparum placental mixed-infection followed by foetal loss: a case report from an unstable transmission area in Brazil

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    Gestational malaria is a multi-factorial syndrome leading to poor outcomes for both the mother and foetus. Although an unusual increasing in the number of hospitalizations caused by Plasmodium vivax has been reported in Brazil, mortality is rarely observed. This is a report of a gestational malaria case that occurred in the city of Manaus (Amazonas State, Brazil) and resulted in foetal loss. The patient presented placental mixed-infection by Plasmodium vivax and Plasmodium falciparum after diagnosis by nested-PCR, however microscopic analysis failed to detect P. falciparum in the peripheral blood. Furthermore, as the patient did not receive proper treatment for P. falciparum and hospitalization occurred soon after drug treatment, it seems that P. falciparum pathology was modulated by the concurrent presence of P. vivax. Collectively, this case confirms the tropism towards the placenta by both of these species of parasites, reinforces the notion that co-existence of distinct malaria parasites interferes on diseases' outcomes, and opens discussions regarding diagnostic methods, malaria treatment during pregnancy and prenatal care for women living in unstable transmission areas of malaria, such as the Brazilian Amazon

    Pathogen-Specific Epitopes as Epidemiological Tools for Defining the Magnitude of Mycobacterium leprae Transmission in Areas Endemic for Leprosy

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    During recent years, comparative genomic analysis has allowed the identification of Mycobacterium leprae-specific genes with potential application for the diagnosis of leprosy. In a previous study, 58 synthetic peptides derived from these sequences were tested for their ability to induce production of IFN-γ in PBMC from endemic controls (EC) with unknown exposure to M. leprae, household contacts of leprosy patients and patients, indicating the potential of these synthetic peptides for the diagnosis of sub- or preclinical forms of leprosy. In the present study, the patterns of IFN-γ release of the individuals exposed or non-exposed to M. leprae were compared using an Artificial Neural Network algorithm, and the most promising M. leprae peptides for the identification of exposed people were selected. This subset of M. leprae-specific peptides allowed the differentiation of groups of individuals from sites hyperendemic for leprosy versus those from areas with lower level detection rates. A progressive reduction in the IFN-γ levels in response to the peptides was seen when contacts of multibacillary (MB) patients were compared to other less exposed groups, suggesting a down modulation of IFN-γ production with an increase in bacillary load or exposure to M. leprae. The data generated indicate that an IFN-γ assay based on these peptides applied individually or as a pool can be used as a new tool for predicting the magnitude of M. leprae transmission in a given population
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