ABSTRACT
We describe what is to our knowledge the first fatal case of central nervous system Enterovirus infection in Brazil. Molecular and phylogenetic characterization revealed that Enterovirus A was the aetiologic agent of this case.
ABSTRACT
In October 2009, our laboratory was contacted by a Brazilian Public Health organization regarding a severe community outbreak of an acute exanthematic and febrile disease in the Brazilian Amazon that primarily affected children. A total of 44 patients with febrile disease were identified by the local public health system, 37 of whom were children between 1 and 9 years of age. Molecular virological and phylogenetic characterization revealed that enterovirus B was the etiological agent of this outbreak, which was characterized by a clinical presentation known as herpangina.
Subject(s)
Disease Outbreaks , Enterovirus B, Human/isolation & purification , Enterovirus Infections/virology , Herpangina/virology , Adult , Brazil , Child , Child, Preschool , Enterovirus B, Human/genetics , Enterovirus Infections/epidemiology , Enterovirus Infections/pathology , Herpangina/epidemiology , Herpangina/pathology , Humans , Infant , PhylogenyABSTRACT
Orf virus (ORFV), the prototype of the genus Parapoxvirus, is the aetiological agent of contagious ecthyma (CE), a pustular dermatitis that afflicts domestic and wild small ruminants. CE is one of the most widespread poxvirus diseases in the world, causing public health impacts. Outbreaks of ORFV have been observed in all geographical regions of Brazil, affecting ovine and caprine herds. The origins, epidemiology and identity of Brazilian ORFVs are unknown, and no comparative or phylogenetic studies of these viruses have been performed. In the present study, we revisited CE outbreaks which occurred until 32 years ago, and we assessed, genetically, five viral isolates. We performed the sequencing and analysis of the three ORFV molecular markers: B2L gene, virus interferon resistance gene (VIR) and the vascular endothelial growth factor gene. Nucleotide and amino acid analysis of the analysed genes demonstrated that Brazilian ORFVs do not form a unique cluster, and presented more similarity to other worldwide ORFV samples than with each other. These data raise the questions of whether there are different worldwide ORFVs circulating in Brazil, or if all the Brazilian ORFV samples are of the same virus taken at distinct time points.
Subject(s)
Disease Outbreaks/veterinary , Ecthyma, Contagious/virology , Goat Diseases/virology , Orf virus/genetics , Animals , Brazil/epidemiology , Ecthyma, Contagious/epidemiology , Genetic Markers/genetics , Goat Diseases/epidemiology , Goats , Orf virus/isolation & purification , Retrospective Studies , SheepABSTRACT
Vaccinia virus strains from the family Poxviridae have been frequently isolated in Brazil and associated with outbreaks of exanthematic disease affecting cows and humans. An ELISA IgG was applied to evaluate the seroprevalence of orthopoxviruses in a community located in a rural settlement in the Amazon region, where no orthopoxvirus outbreaks have yet been reported. An overall seroprevalence of 27.89% was found, and it was 23.38% in the non-vaccinated population (smallpox vaccination). These results strongly suggest that orthopoxviruses circulate in this population, and it is the first finding of seropositivity for orthopoxviruses in a population without any previously reported outbreaks.
Subject(s)
Immunoglobulin G/blood , Orthopoxvirus/immunology , Poxviridae Infections/epidemiology , Adolescent , Adult , Aged , Antibodies, Viral/blood , Brazil/epidemiology , Child , Child, Preschool , Cross-Sectional Studies , Enzyme-Linked Immunosorbent Assay , Female , Humans , Infant , Male , Middle Aged , Odds Ratio , Poxviridae Infections/immunology , Poxviridae Infections/virology , Risk Factors , Rural Population , Seroepidemiologic Studies , Young AdultABSTRACT
Different molecular configurations of human beta interferon were titrated with the standard reference antiserum of the National Institutes of Health (NIH) which had been prepared with natural beta fibroblast interferon in order to determine to what extent differences in these configurations would influence the neutralization of the antiviral action of interferon. Neutralization tests were carried out in Vero cells by diluting both interferon and antiserum. Encephalomyocarditis virus was employed as challenge virus. The neutralization titer was considered to have been reached when the effect of eight units of interferon was reduced to one. Two natural beta interferons prepared from fibroblasts and from amniotic membranes gave similar high titers. However, titers were reduced five-fold with recombinant interferons expressed in Escherichia coli, which do not contain carbohydrate, one with the natural sequence and a mutant with a single amino acid substitution (cysteine for serine). The NIH antiserum did not neutralize the effect of a protein fraction from amniotic membranes antigenically different from the human alpha, beta, or gamma interferons but having the biological activity of interferon. We conclude that the carbohydrate moieties of human beta interferons are essential for their recognition by the NIH antiserum and that antibodies specific for human recombinant beta interferon, which does not contain carbohydrate, are needed.
Subject(s)
Humans , Antigenic Variation/immunology , Interferon-beta/immunology , Amniotic Fluid/immunology , Fibroblasts/immunologyABSTRACT
Human amniotic interferon was investigated to define the species specificity of its antiviral action and compare its anti-cellular and NK cell stimulating activities with those of other human interferons. The antiviral effect was titrated in bovine (RV-IAL) and monkey (VERO) cells. Amniotic interferon exhibited, in bovine cells, 5% of the activity seen in monkey cells, while alpha interferon displayed 200%. No effect was detected with either beta or gamma interferon in bovine cells. Daudi cells were exposed to different concentrations of various interferons and the cell numbers were determined. The anticellular effect of the amniotic interferon reached its peak on the third day of incubation. Results suggested a higher activity for alpha and gamma interferons and a lower activity for beta when compared to amniotic interferon. Using total mononuclear cells as effector cells and K 562 as target cell in a 51Cr release assay, it was demonstrated that low concentrations of amniotic interferon consistently stimulated NK cell activity in cells derived from several donors, the results indicating a higher level of activity with this interferon than with alpha and beta interferons
Subject(s)
Interferons/biosynthesis , Antiviral Agents/analysisABSTRACT
The molecular weight and the electrofocusing profile of human amniotic membrane interferon (IFN-AM) were determined. When submitted to gel filtration, IFN-AM showed a single 26-28 kDa component; in polyacrylamide gel electrophoresis one component of 19,500. In electrofocusing, IFN-AM displayed a terogeneity was reduced by previous treatment of IFN-AM with neuraminidase. IFN-AMis a siaglycoprotein similarto human beta IFN in terms of antigenicity but different from it in electrofocusing profile
