Genetic characterization of dengue virus type 3 isolates in the State of Rio de Janeiro, 2001

The genetic characterization of dengue virus type 3 (DEN-3) strains isolated from autochthonous cases in the State of Rio de Janeiro, Brazil, in 2001 is presented. Restriction site-specific (RSS)-PCR performed on 22 strains classified the Brazilian DEN-3 viruses as subtype C, a subtype that contains viruses from Sri Lanka, India, Africa and recent isolates from Central America. Nucleic acid sequencing (positions 278 to 2550) of one DEN-3 strain confirmed the origin of these strains, since genotype III - classified by sequencing - and RSS-PCR subtype C are correlated. This genetic subtype has been associated with hemorrhagic dengue epidemics and the information provided here could be useful to implement appropriate prevention and control measures

Molecular typing of dengue virus type 2 in Brazil Tipificação molecular do vírus da dengue tipo 2 no Brasil

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).<br>A tipagem de cepas é uma ferramenta fundamental para a análise epidemiológica molecular e pode fornecer informações importantes sobre a dispersão dos vírus dengue. Neste trabalho, foi realizada a caracterização molecular de amostras de vírus DEN-2 isoladas no Brasil entre 1990-2000, de áreas geograficamente e temporalmente distintas, com o objetivo de investigar a distribuição genética deste sorotipo circulante no país. A reação em cadeia pela polimerase baseada em sítios de restrição específicos (RSS-PCR) apresentou o mesmo padrão para as 52 amostras Brasileiras, mostrando a circulação de apenas uma variante de vírus DEN-2. A análise filogenética utilizando alinhamento progressivo de sequências de 240 nucleotídeos da junção E/NS1 de 15 cepas mostrou que estas pertencem ao genotipo III (genotipo Jamaica)

Human enteric viruses in a wastewater treatment plant: evaluation of activated sludge combined with UV disinfection process reveals different removal performances for viruses with different features

This study assess the quality of wastewater through the detection and quantification of important viruses causing gastroenteritis at different stages of the wastewater treatment process in an activated-sludge wastewater treatment plant with ultraviolet disinfection. Ten sampling events were carried out in a campaign along a period of 18 months collecting wastewater samples from the influent, after the activated-sludge treatment, and after the final disinfection with UV radiation. Samples were concentrated through ultracentrifugation and analysed using retro-transcription, PCR and real time quantitative PCR protocols, for detection and quantification of Group A Rotavirus (RVA), Human Astrovirus (HAstV), Norovirus Genogroup II (NoV GII) and Human Adenovirus (HAdV). HAdV (100%), NoV GII (90%), RVA (70%) and HAstV (60%) were detected in influent samples with concentration from 1·4 (NoV GII) to 8·0 (RVA) log 10  gc l −1 . Activated-sludge treatment reached well quality effluents with low organic material concentration, although nonstatistical significant differences were registered among influent and postactivated sludge treatment samples, regarding the presence and concentration for most viruses. All post-UV samples were negative for NoV GII and HAstV, although RVA and HAdV were detected in 38% and 63% of those samples respectively, with concentration ranging from 2·2 to 5·5 and 3·1 to 3·4 log 10  gc l −1 . Significance and Impact of the Study: This study demonstrates that an activated-sludge wastewater treatment plant with UV disinfection reduces to levels below the detection limit those single-stranded RNA viruses as noroviruses and astroviruses and reach significant lower levels of rotaviruses and adenoviruses after the complete treatment process.Fil: Lizasoain, A.. Universidad de la República; UruguayFil: Tort, L.F.L.. Universidad de la República; UruguayFil: García, M.. Universidad de la República; UruguayFil: Gillman, L.. Universidad de la República; UruguayFil: Alberti, A.. Universidad de la República; UruguayFil: Leite, J.P.G.. Fundación Oswaldo Cruz; Brasil. Instituto Oswaldo Cruz; BrasilFil: Miagostovich, M.P.. Instituto Oswaldo Cruz; Brasil. Fundación Oswaldo Cruz; BrasilFil: Pou, Sonia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; ArgentinaFil: Cagiao, A.. Obras Sanitarias del Estado; UruguayFil: Razsap, A.. Obras Sanitarias del Estado; UruguayFil: Huertas, J.. Obras Sanitarias del Estado; UruguayFil: Berois, M.. Universidad de la República; UruguayFil: Victoria, M.. Universidad de la República; UruguayFil: Colina, R.. Universidad de la República; Urugua

Secondary dengue infection in schoolchildren in a dengue endemic area in the State of Rio de Janeiro, Brazil Infecção secundária por dengue em escolares numa região endêmica para o dengue no Estado do Rio de Janeiro, Brasil

A seroepidemiologic survey was carried out in schoolchildren from public schools of the Niterói municipality, state of Rio de Janeiro, Brazil, after a period of sequential epidemics by dengue virus type 1 and 2 (DEN-1 and DEN-2). 450 blood samples were obtained by fingertip puncture and collected on filter paper discs. The hemagglutination inhibition (HAI) test was carried out using DEN-1 and DEN-2 antigens. HAI titres were demonstrated in 66% (297/450) of the sera and the geometric means of the titres were 1/182 and 1/71 for DEN-1 and DEN-2, respectively. Secondary infections were observed in 61% (181/297) of positive cases. Among these, 75% (135/181) were under fifteen years old. No dengue haemorrhagic fever (DHF) was reported in these children. Asymptomatic or oligosymptomatic infections were detected in 56% of the studied population. The absolute and relative frequencies of positive tests by age group and sex did not evidence statistically significant difference. The number of individuals infected probably produced a immunologic barrier responsible for the non occurrence of dengue epidemic in the latter years.<br>Após um período de epidemias sequenciais pelos vírus dengue tipo 1 e 2 (DEN-1 e DEN-2), foi realizado um estudo soroepidemiológico em uma amostra de escolares da rede pública de ensino do município de Niterói; 450 amostras de sangue foram obtidas através de punção da polpa digital, coletadas sobre discos de papel de filtro e testadas para a detecção de anticorpos inibidores da hemaglutinação (1HA) para DEN-1 e DEN-2. Das amostras testadas, 66,0% (297/450) apresentaram títulos de anticorpos IHA e as médias geométricas dos títulos de anticorpos foram de 1/182 e 1/71, para DEN-1 e DEN-2, respectivamente. Cerca de 61,0% (181/297) daqueles com anticorpos IHA tiveram infecção secundária. Destes, 75% (135/181) tinham idade igual a ou menor do que 15 anos. Nenhum caso de dengue hemorrágico foi relato entre os participantes do estudo. Cerca de 56,0% dos casos com anticorpos IHA tiveram infecção assintomática ou oligossintomática. As freqüências absoluta e relativa das sorologias positivas por idade e sexo não evidenciaram diferenças estatisticamente significativas. Acredita-se que a barreira imumtária formada pelos individuos infectados pelo DEN-2 seja a responsável pela não ocorrência do dengue de forma epidêmica nos anos imediatamente posteriores ao presente estudo