First report of human astrovirus MLB2 in Brazil detected in feces of children with acute gastroenteritis living in the state of Roraima, Northern Brazil

ABSTRACT Human astrovirus (HAstV) 1-8 and highly divergent HAstVMLB1−3 genotypes have been detected in children both with and without acute gastroenteritis (AGE). One hundred and seventy fecal samples from children (≤5 years old) living in the Amazon region were evaluated for the presence of HAstV1-8, HAstV MLB1−3 and HAstVVA1−3, using an usual RT-PCR protocol and a new protocol with specific primers designed to detect HAstVMLB1−3. HAstVMLB1 and HAstV MLB2, as well as the HAstV3 and 5 genotypes were detected. HAstVMLB1−2 genotype was detected for the first time in Brazil at a frequency of 3.5% (6/170).

Coinfección por astrovirus y Neisseria meningitidis serogrupo B en una niña / Coinfection by astrovirus and Neisseria B meningitidis in a girl

La infección meningocócica tiene una elevada morbimortalidad. Las coinfecciones virales han sido descritas, fundamentalmente, por virus herpes y respiratorios. Se presenta una paciente que ingresó al Servicio de Emergencia con convulsión tónico-clónica, hipotensión, taquicardia y escala de Glasgow posterior baja. En la Unidad de Cuidados Intensivos mantuvo alteración del nivel de conciencia y requirió estabilización hemodinámica. Se inició antibioterapia de amplio espectro. La paciente mostró deposiciones líquidas malolientes, sin sangre, que fueron cultivadas y estudiadas mediante reacción en cadena de la polimerasa. El líquido cefalorraquídeo fue normal. Las deposiciones resultaron positivas para astrovirus. Se confirmó, mediante reacción en cadena de la polimerasa en sangre, la presencia de Neisseria meningitidis serogrupo B. Se presenta el primer caso pediátrico de coinfección por astrovirus y Neisseria meningitidis. Este virus debería incluirse entre las causas de coinfección para descartar en caso de clínica abdominal predominante, vómitos o deposiciones líquidas.

Meningococcal infection associates high morbidity and mortality. Viral coinfection has been described mainly with herpes and respiratory virus. We describe a child who suffered a tonic-clonic seizure with hypotension, tachycardia and low Glasgow Coma Scale. She maintained an altered mental status and required hemodynamic stabilization in the Pediatric Intensive Care Unit. Wide spectrum antibiotherapy was initiated. She suffered large and foul-smelling liquid not bloody stools which were cultured and studied by polymerase chain reaction. The cerebrospinal fluid was normal. Later the polymerase chain reaction stools were positive to astrovirus, and the blood polymerase chain reaction was positive to Neisseria meningitidis group B. As far as we know, this is the first case of astrovirus and Neisseria meningitidis coinfection described in children. This virus should be considered as new cause of viral coinfection to discard if unexplained abdominal pain or vomits and liquid stools are observed.

Detection and genetic characterization of Mamastrovirus 5 from Brazilian dogs

Abstract Mamastrovirus 5 (MAstV5), belonging to the Astroviridae (AstV) family, previously known as canine astrovirus or astrovirus-like particles, has been reported in several countries to be associated with viral enteric disease in dogs since the 1980s. Astroviruses have been detected in fecal samples from a wide variety of mammals and birds that are associated with gastroenteritis and extra enteric manifestations. In the present study, RT-PCR was used to investigate the presence of MAstV5 in 269 dog fecal samples. MAstV5 was detected in 26% (71/269) of the samples. Interestingly, all MAstV5-positive samples derived from dogs displaying clinical signs suggestive of gastroenteritis, other enteric viruses were simultaneously detected (canine parvovirus, canine distemper virus, canine coronavirus, canine adenovirus and canine rotavirus). Based on genomic sequence analysis of MAstV5 a novel classification of the species into four genotypes, MAstV5a-MAstV5d, is proposed. Phylogenetic analyses based on the ORF2 amino acid sequences, samples described herein grouped into the putative genotype 'a' closed related with Chinese samples. Other studies are required to attempt the clinical and antigenic implications of these astrovirus genotypes in dogs.

Monitoreo y confección de mapas que reflejen la contaminación estacional por astrovirus humano en las aguas del río Suquía de la ciudad de Córdoba, Argentina

El agua es reconocida como el recurso natural más preciado de nuestro planeta, el descuido de las fuentes de agua ligado a las actividades humanas, genera contaminación sostenida en el tiempo y lleva como resultado a la disminución en la calidad y cantidad de este recurso esencial. La presencia de patógenos virales en las fuentes de agua tienen un alto impacto socioeconómico tanto en las naciones en desarrollo como en las desarrolladas. La ocurrencia de virus entéricos como rotavirus, astrovirus, norovirus y adenovirus en el ambiente, en aguas y alimentos, ha sido reportada en los países desarrollados y asociada a gastroenteritis de origen viral relacionada con el consumo de agua contaminada con materia fecal. En Argentina y otros países de Sudamérica no hay regulaciones sobre el monitoreo de virus patógenos en matrices acuosas y existen pocos estudios de monitoreo ambiental de patógenos virales (rotavirus, norovirus, adenovirus, enterovirus) en aguas superficiales de ríos y lagos. Más aún, no se dispone de información sobre el monitoreo ambiental de astrovirus en aguas superficiales en la Argentina. En este trabajo de tesis se abordó el estudio de astrovirus humano en aguas del río Suquia con los objetivos de: 1. Evaluar las aguas del río Suquía como potencial fuente de transmisión de astrovirus humano (HastV). 2. Conocer si el río Suquía está integrado a la historia natural de circulación de astrovirus en nuestro medio. A los fines de cumplir los objetivos planteados se analizaron un total de 28 muestras de agua recolectadas en 7 puntos representativos del río Suquía, cubriendo el muestreo desde el nacimiento (Dique San Roque) hasta que el río abandona la Ciudad de Córdoba (Cantera San José).

Abstract: Water is the most precious natural resource on Earth; neglected water sources associated with anthropogenic activities generate sustained contamination over time and results in a reduction in quantity and quality of this essential resource. The presence of pathogenic virus in water sources has a high socioeconomic impact, both in developing and developed countries. The occurrence of enteric virus, such as rotavirus, astrovirus, norovirus and adenovirus, in the environment, water and food has been reported in developed countries associated with viral gastroenteritis related to consumption of fecal-contaminated water.In Argentina as well as in other South American countries, there are regulations no requiring monitoring of pathogenic viruses in water matrices, and few studies have focused on environmental monitoring of viral pathogens (rotavirus, norovirus, adenovirus, enterovirus) in surface waters of rivers and lakes. Moreover, there is no information available on environmental monitoring of astrovirus in surface waters in Argentina. This thesis work focuses on the study of human astrovirus in the waters of the Suquía river, with the general aims of: 1. evaluating the waters of Suquía river as a potential source of transmission of human astrovirus (HastV), and 2. Knowing if Suquía river is integrated to the natural history of astrovirus circulation in our environment. To meet the aims of this work, a total of 28 water samples were collected from 7 representative points along Suquía river course, with sampling covering from the riverhead (San Roque Dam) to the site where the river leaves the city of Córdoba (San José quarry).

Estudo retrospectivo dos astrovirus humanos associados a casos de gastrenterite aguda em crianças residentes em tres regioes do Brasil: nordeste, sudeste e sul no período de 1994 a 2011 / Retrospective study of human astrovirus associated with cases of acute gastroenteritis in children living in three regions of Brazil: northeast, southeast and south in the period 1994-2011

Os astrovírus humanos (HAstVs) pertencem a família Astroviridae e são associados agastrenterite aguda (GA) em crianças menores de cinco anos, tanto nos paísesdesenvolvidos como naqueles em desenvolvimento, o que os tornam de interesse nocampo da Saúde Pública. A família Astroviridae é dividida em dois gêneros:Avastrovirus e Mamastrovirus. No gênero Mamastrovirus, encontram-se os astrovirusassociados à infecção em mamíferos, tanto humanos como animais. Até 2008, osastrovirus associados a doenças em humanos eram restritos a oito genótipos,conhecidos como HAstV 1-8. A partir de então novos HAstVs foram sendo descritos,associados a doenças em humanos, como os HAstVs MLB1-3 e os HAstVs VA1-4.Opresente estudo consiste no estudo epidemiológicos retrospectivos (1994 a 2011) paradetecção e caracterização molecular de HAstV em amostras de fezes provenientes decrianças com menos de cinco anos de idade com GA, em diferentes regiões do Brasil:Nordeste, Sudeste e Sul. Incluem-se neste trabalho três estudos: 1) Estudo dosHAstV em casos esporádicos de GA ocorridos em crianças menores de cinco anos deidade, em três regiões brasileiras (Nordeste, Sudeste e Sul), durante o período de2005 a 2011, incluindo a pesquisa dos novos HAstV; 2) Estudo dos HAstV em criançascom GA, atendidas na creche Bertha Lutz, FIOCRUZ-RJ, durante o período de janeirode 1994 a dezembro de 2008; 3)...

Human astrovirus (HAstVs), belong to Astroviridae family, and are associatedwith acute gastroenteritis (GA) in children under five years-old, both indeveloped and in developing countries, which makes them of interest in thePublic Health field. The Astroviridae family is divided into two genera:Avastrovirus and Mamastrovirus. Mamastrovirus are the astrovirusesassociated to infection in mammals, both humans and animals. By 2008, theastrovirus associated with human disease were restricted to eight genotypes,known as HAstV 1-8. Since then, new HAstVs have been described, associatedwith human disease, such as HAstVs MLB1-3 and HAstVs VA1-4. The presentstudy is the retrospective epidemiological study (1994 to 2011) for the detectionand molecular characterization of HAstV in stool samples from children underfive years old presenting GA, in different regions of Brazil: Northeast, Southeastand South. Three studies are presented: 1) Study of HAstV in sporadic cases ofGA occurred in children under five years old in three Brazilian regions(Northeast, Southeast and South) from 2005 to 2011, including the descriptionof a new HAstV; 2) Study of HAstV in children with GA, attending the day careBertha Lutz, FIOCRUZ-RJ from January 1994 to December 2008 and 3) Studyof HAstV in children under two years old presenting GA and hospitalized inNiteroi, Rio de Janeiro from April to September 2003. The detection of HAstVwas performed using different protocols for detection and molecularcharacterization such as: Reverse–transcriptase polymerase chain reaction,(RT- PCR), Single step RT -PCR (OneStep RT-PCR) and RealTime RT- PCR.The HAstV detected were characterized by partial sequencing of ORF2 regionof the viral genome. The study 1 demonstrated the HAstV detection frequencyin 7.1 % of samples, and described the first ASTV MLB1 in Brazil. Themolecular characterization identified the circulation genotypes HAstV -1, 2, 3, 4,5, 6 and 8...

The circulation of human astrovirus genotypes in the Central West Region of Brazil

Out of 1,588 faecal samples of children taken from three locations of the Central West Region of Brazil, 57 were positive for astroviruses (HAstVs) using reverse transcription-polymerase chain reaction (RT-PCR). They were genotyped by nested RT-PCR and/or genomic sequencing. HAstV-1 (42.8 percent), HAstV-2 (23.2 percent), HAstV-3 (3.6 percent), HAstV-4 (14.3 percent) and HAstVs -5, -6, -7 and -8 (1.8 percent each) were detected. In Goiânia and Campo Grande, HAstV-1 was the most frequently detected genotype while in Brasília (DF) it was HAstV-2. Shifts in the circulation of astrovirus genotypes were observed in DF and Campo Grande. All samples collected by rectal swabs were viral negative. The astrovirus genotypes were detected in all age groups and there was no correlation between genotype and age group.

Epidemiological aspects of astrovirus and coronavirus in poults in the South Eastern Region of Brazil / Aspectos epidemiológicos associados à prevalência de Astrovirus e Coronavirus em lotes de perus da Região Sudeste do Brasil

A survey of Turkey Coronavirus (TCoV) and Astrovirus (TAstV-2) prevalence was carried out from February to December during 2006 year in semiarid region of Brazil, from a turkey producer area, localized in South Eastern of Brazil. To asses the risk factor related to clinical material, climatic condition and type of RT-PCR applied, cloacal swabs (CS), faeces, sera, bursa of Fabricius (BF), thymus (TH) and spleen (SP) and ileum-caeca region were collected from 30-day-old poults suffering of enteritis episode characterized as poult enteritis mortality syndrome (PEMS). The PEMS clinical features were characterized by watery to foamy faeces, light brown-yellow in colour and low mortality rate. Meteorological data (rainfall and relative humidity) observed during along the study presented monthly average temperature ranging from 39.3 and 31.2ºC, precipitation in rainy season from 40 to 270.3 mm/month, and no rain during dry season. Simplex RT-PCR gave odds ratio (OR) values suggesting that ileum-caeca region is at higher chance (OR=1.9; p=0.9741) to have both viral RNA than faeces (OR=1.5; p=0.7319). However, multiplex RT-PCR showed 3.98 (p=0.89982) more chance to give positive results in faeces than CS at dry season. The major risk factors seem to be low rate of humidity and high temperatures at winter, probably responsible for spread, easily, the TCoV and TAstv-2 among the flocks. The positive results of both virus suggested that they can play an important role in enteric disorders, associated to low humidity and high temperatures frequently found in tropical countries.

O presente estudo foi conduzido para avaliar a prevalência do Coronavirus dos perus (TCoV) e Astrovirus tipo 2 (TAstV-2) entre os meses de Fevereiro a Dezembro de 2006, em uma região produtora localizada no semi-árido a Sudeste do Brasil. Os principais fatores de risco associado a prevalência foram material clínico analisado, condições climáticas e tipo de técnica molecular empregada. Os sinais clínicos foram caracterizados como intenso fluido intestinal e baixo crescimento em aves jovens, sendo o material coletado swabs cloacais, fezes, soros, bursa de Fabrícius, segmentos do intestino delgado, timo e baço. Os dados meteorológicos (índice pluviométrico e umidade relativa) desta região, durante o período de estudo, foram de temperatura média mensal variando de 39.3 a 31.2ºC, precipitação na época chuvosa variando de 40 a 270.3mm/mês e ausência de chuva na estação fria e seca. A técnica de simplex RT-PCR resultou em valores de odds ratio (OR) que sugerem que a região do intestino delgado (junção íleo-cecal) possui alta chance (1.9 vezes) de gerar resultados positivos na amplificação de RNA viral que as fezes (1.5 vezes) analisadas. A técnica de multiplex RT-PCR demonstrou ser 3.98 vezes mais eficiente em promover resultados positivos nas fezes que nos swabs cloacais, durante a época de inverno. Os maiores fatores de risco encontrados foram baixa umidade relativa associada a altas temperaturas, durante a estação seca, o que pode permitir uma maior disseminação aérea do ambos os vírus entre os lotes estudados. A alta prevalência detectada para dois vírus sugerem que, no Brasil, estes representam os maiores responsáveis pelos surtos de enterite viral nas regiões semi-áridas, associado a baixas umidades e altas temperaturas típicas de países tropicais.

Caracterización molecular de calicivirus aislados de brotes de gastroenteritis ocurridos en la Argentina durante los años 2005 y 2006 / Molecular characterization of calicivirus strains detected in outbreaks of gastroenteritis occurring in Argentina during 2005 and 2006

Con el objetivo de determinar la incidencia de calicivirus, rotavirus y astrovirus en brotes de gastroenteritis ocurridos en diversas regiones de la Argentina durante los años 2005 y 2006, se analizaron muestras de materia fecal provenientes de 7 brotes con resultado de coprocultivo negativo. Para el diagnóstico de rotavirus se utilizó un ELISA comercial, mientras que para el diagnóstico de calicivirus y astrovirus se utilizó el método de RT-PCR. De las 74 muestras analizadas, 20 fueron positivas para calicivirus, 17 para rotavirus y una para astrovirus. No se identificaron infecciones virales mixtas. En 5 muestras positivas para calicivirus se secuenció una región del gen de la polimerasa; 4 de ellas correspondieron al género Norovirus y una al género Sapovirus. El análisis filogenético de las muestras secuenciadas determinó la presencia de norovirus de los genogrupos GI y GII; dentro de este último, se identificaron los genotipos GII-4, GII-b y GII-17. El análisis de la muestra en la cual se identificó sapovirus reveló la presencia del genotipo GI-1. Este estudio representa una continuación del análisis epidemiológico molecular de calicivirus asociados a brotes de gastroenteritis iniciado en 2004 y constituye la primera comunicación de la circulación de norovirus del genotipo GII-17 en la Argentina.

In order to determine the incidence of calicivirus, rotavirus and astrovirus in outbreaks of gastroenteritis occurring in different regions of Argentina during 2005 and 2006, fecal samples from seven nonbacterial outbreaks were analyzed. A commercial ELISA was used for rotavirus detection, while RT-PCRs were used for calicivirus and astrovirus. Of the 74 samples analyzed, 20 were calicivirus positive, 17 were rotavirus positive and one was astrovirus positive. No mixed infections were detected. A partial region of the RdRp gene was sequenced in five calicivirus positive-samples; 4 of them belonged to Norovirus genus and one to Sapovirus genus. The phylogenetic analysis of norovirus-positive-samples revealed the presence of strains from genogroups GI and GII; genotypes GII- 4, GII-b and GII-17 were identified within the latter. Phylogenetic the sapovirus-positive-sample revealed the presence of genotype GI-1. This study represents a follow-up of the of molecular epidemiology analysis of calicivirus associated to gastroenteritis outbreaks that have been carried out by our group since 2004, and constitutes the first report of the circulation of genotype GII-17 in Argentina.

Adenovirus, calicivirus and astrovirus detection in fecal samples of hospitalized children with acute gastroenteritis from Campo Grande, MS, Brazil

We analyzed fecal samples from hospitalized children up to three years of age with acute gastroenteritis at Campo Grande, Mato Grosso do Sul, Brazil, from May 2000-January 2004. Astrovirus and calicivirus were detected by Reverse Transcription-Polymerase Chain Reaction and adenovirus was detected using the Rotavirus and Adenovirus combined immunoenzyme assay. Astrovirus, adenovirus and calicivirus were detected at rates of 3.1 percent, 3.6 percent and 7.6 percent, respectively. These results re-emphasize the need for the establishment of regional vigilance systems to evaluate the impact of enteric viruses on viral gastroenteritis.

Molecular characterization of astrovirus in stool samples from children in São Paulo, Brazil

The purpose of this study was to characterize astrovirus in faecal samples collected from children with and without diarrhea in São Paulo, Brazil, grouped into two sets: EPM and HU. Detection and genotyping were carried out using reverse transcription nested polymerase chain reaction (RT-PCR) with specific primers directed towards the genome open reading frame 2 (ORF2). Results for EPM set showed that 66/234 (28.2 percent) were positive: 28/94 (29.7 percent) from children with acute diarrhea, 14/45 (31.1 percent) with persistent diarrhea, and 9/55 (16.3 percent) from control individuals. No data was available for 15/40 (37.5 percent) of samples. Mixed infections with other viruses were found in 33 samples. In the HU, 18/187 (9.6 percent) were positive: 12/158 (7.6 percent) from individuals with acute diarrhea and 6/29 (20.7 percent) from control children. Four samples were mixed with other viruses. Out of 66 astrovirus positive EPM samples, 18 (27.2 percent) were characterized as human astrovirus type-1 (HAstV-1), two (3.0 percent) as HAstV-2, two (3.0 percent) as HAstV-3, and three (4.5 percent) as HAstV-8. Among 18 astrovirus positive HU samples, one (5.5 percent) was characterized as HAstV-1, six (33.3 percent) as HAstV-2, and one (5.5 percent) as HAstV-8. Two HAstV-8 genotyped samples were further confirmed by nucleotide sequencing. Our results shows that astroviruses are circulating in a constant manner in the population, with multiple serotypes, in higher frequency than it was described for other Brazilian regions. For the first time in Sao Paulo, Brazil, it was shown that astroviruses play an important role in children gastroenteritis, as described for most locations where they were detected.

First detection of a human astrovirus type 8 in a child with diarrhea in Belém, Brazil: comparison with other strains worldwide and identification of possible three lineages

This study describes the genetic relationships of the first human astrovirus type-8 (HAstV-8) detected in Belém-Brazil, during a public hospital-based study. This strain was compared with other HAstV-8 strains identified elsewhere which have sequences available at GeneBank. The regions ORF1a (primers Mon348/Mon340) and ORF2 (primers Mon269/Mon270) were analyzed by nucleotide sequencing and a high similarity rate was observed among the Belém strain and other HAstV-8 strains. In ORF1a, homology values of 93-100 por cento were detected, and in ORF2 96-99 por cento. Considering the sequence variation (7 por cento) observed in ORF2 region, it was suggested that HAstV-8 strains could be divided in three different lineages.

Astrovirus infection in children living in the Central West region of Brazil

This study presents data regarding the circulation of astrovirus in Goiânia-GO and Brasília-DF. These viruses were detected in fecal samples from hospitalized children up to five years old with and without acute gastroenteritis. A total of 1244 fecal samples were collected in two periods, 1994 to 1996 (Brasília) and 1998 to 2002 (Goiânia and Brasília), and were analyzed for viral RNA using the reverse transcription-polymerase chain reaction (RT-PCR). Positivity rates of 4.3 and 0.5 percent for astrovirus were observed in children with acute gastroenteritis and those without gastroenteritis, respectively. Among children with gastroenteritis no statistically significant difference was seen with regards to viral positivity rates in relation to gender and age. However, a higher incidence rate was observed for children from Brasília aged 36 months or more. Overall, astroviruses occurred predominantly from September to March in the two cities, suggesting a seasonal pattern for these viruses which coincides with the highest relative air humidity period. The results of this study highlight the importance of astrovirus as an etiologic agent of acute gastroenteritis in children of the Central West region of Brazil.

Astrovírus / Astrovirus

Os astrovírus têm sido descritos como importantes enteropatógenos associados à gastrenterite aguda em crianças e outros grupos etários em todo o mundo. São vírus pertencentes à família Astroviridae que possui dois gêneros dos quais o Mamastrovirus acomete o homem. Estes vírus possuem RNA de fita simples, de polaridade positiva e são poliadenilados na extremidade 3'. São desnudos, apresentam um nucleocapsídeo de simetria icosaédrica, têm diâmetro de 28nm a 40nm e uma arquitetura peculiar com projeções superficiais semelhantes a uma estrela de cinco a seis pontas. Atualmente são conhecidos oito tipos de astrovírus humanos (HAstVs). O conhecimento sobre a epidemiologia da infecção por astrovírus e a disponibilidade de métodos de detecção rápidos e eficazes destes vírus são importantes para as estratégias de prevenção e controle.

Prevalence and genetic diversity of astroviruses in children with and without diarrhea in São Luís, Maranhão, Brazil

Human astroviruses (HAstV) have been increasingly identified as important etiological agents of acute gastroenteritis in children up to five years old. The aim of this study was to determine the prevalence and genotype diversity of HAstV in children with symptomatic and asymptomatic infections in São Luís, Maranhão, Brazil. From June 1997 to July 1999 a total of 183 fecal samples 84 from symptomatic and 99 from asymptomatic children were tested by enzyme immunoassay for HAstV. Prevalence rates were found to be 11 and 3 percent for symptomatic and asymptomatic children, respectively. Reverse transcription-polymerase chain reaction (RT-PCR) was carried out in 46 specimens (26 symptomatic and 20 asymptomatic) including the 12 samples that were positive by enzyme immunoassay (EIA). The overall positivity yielded by both methods was 8 percent (15/184); of these, 11 percent (9/84) for symptomatic and 5 percent (5/99) for those without symptoms or signs. Sequence analysis of amplicons revealed that HAstV-1 genotype was the most prevalent, accounting for 60 percent of isolates. Genotypes 2, 3, 4, and 5 were also detected, as one single isolate (10 percent) for each type. Variations in the sequences were observed when Brazilian isolates were compared to prototype strains identified in the United Kingdom. No seasonal pattern of occurrence was observed during these two years of study, and peak detection rate was observed in children aged between 3 and 6 months in the symptomatic group, and between 18 and 24 months in the controls.

Childhood astrovirus-associated diarrhea in the ambulatory setting in a Public Hospital in Cordoba city, Argentina

Os astrovírus humanos têm sido identificados como importantes agentes de diarréias em crianças embora o impacto da sua infecção não tenha sido esclarecido. Este estudo não só mostra os resultados das características epidemiológicas e clínicas, mas também o impacto da infecção por astrovírus em pacientes ambulatoriais de um Hospital Público da cidade de Córdoba na Argentina. Escolheram-se randomicamente 97 pacientes ambulatoriais com menos de 36 meses, entre fevereiro de 2001 e janeiro de 2002, que consultaram por diarréia. Pesquisou-se antígeno de astrovírus por ensaio imuno-enzimático em uma única amostra de fezes por paciente estudado. Determinou-se a presença de astrovírus em 12,37 por cento dos casos de diarréia. Todos os casos positivos foram em crianças de 4 a 18 meses, mas o índice mais elevado se apresentou em crianças de 4 a 6 meses (23,80 por cento). Os sintomas de diarréia associada a astrovírus foram febre 41,66 por cento; vômitos 25,00 por cento e desidratação 8,33 por cento; ou seja, 16,66 por cento dos pacientes precisaram hospitalização. A presença de astrovírus foi anual sem se observar comportamento sazonal, semestre frio 15,21 por cento versus semestre quente 9,80 por cento p > 0,05. Em nossa pesquisa, uma de cada 74 crianças seria atendida anualmente por apresentar um episódio de diarréia associada a astrovírus no hospital público e um de cada 8 casos de diarréia poderia atribuir-se à infecção por astrovírus. Astrovírus é uma infecção sintomática em pacientes pediátricos ambulatoriais, representando 12,37 por cento da morbidade por diarréia.

An outbreak of gastroenteritis associated with astrovirus serotype 1 in a day care center, in Rio de Janeiro, Brazil

Between June 4th and June 20th1996 rotavirus, adenovirus, and astrovirus (HAstrV) were investigated in fecal samples from 27 children under three years old with acute diarrhea, attending the Bertha Lutz day care center, in Rio de Janeiro. All fecal samples were analyzed by polyacrylamide gel electrophoresis (PAGE), reverse transcriptase polymerase chain reaction (RT-PCR), enzyme immunoassays (EIA), and electron microscopy (EM). Nine of them (33 percent) showed positive results for HAstrV by at least one of the employed methodologies. Eight were positive by RT-PCR and EIA, and six by EM. All positive samples were inoculated onto HT-29 (human colon adenocarcinoma) cultured cells for HAstrV isolation and seven were positive after three passages. The sequencing analysis of eight RT-PCR products (449 bp) from gene that codifies VP2 protein, showed a total nucleotide identity among them and 98 percent with HAstrV-1 (strain Oxford type 1). This is the first report of a gastroenteritis outbreak associated with HAstrv-1 in a day care center in Rio de Janeiro and it reinforces the importance of this virus in association with infantile acute gastroenteritis

The epidemiology of acute viral gastroenteritis in hospitalized children in Cordoba city, Argentina: an insight of disease burden

Information concerning the disease burden of viral gastroenteritis has important implications for the use and monitoring the impact of public health policies. The present study, carried out in Córdoba city, Argentina, documents the epidemiology of severe viral diarrhea as well as the burden of viral gastrointestinal disease in the hospital children admission. A total of 133 stools were collected from hospitalized children (Town Childhood Hospital) suffering from acute diarrhea and studied for the presence of Group A rotavirus, astrovirus and adenovirus 40/41 by enzyme-immuno assay, between November 1997 and October 1998. Enteric viruses accounted for 42.1 percent of the total diarrheal cases analyzed. Group A rotaviruses, astroviruses, adenoviruses 40/41 and mixed infections were found in 35.3, 4.5, 1.5, and 0.8 percent studied specimens respectively. We estimated that 1 in 27 children in the 0-35 month-old cohort/range would be annually hospitalized for a viral gastroenteritis illness. The major impact on viral diarrhea lies on rotaviral infection, accouting for 84.0 percent of the viral diarrheal cases analyzed and for approximately one third of severe diarrheas requiring hospital admission in Córdoba City, Argentina