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.

An unusual case of concomitant infection with chicken astrovirus and group A avian rotavirus in broilers with a history of severe clinical signs

A molecular study of intestinal samples from 21 broiler flocks with a history of enteritis revealed that 23.8% and 14.3% were positive for chicken astrovirus (CAstV) and avian rotavirus (ARV), respectively. CAstV and group A ARV were simultaneously detected in only one broiler flock. Birds in this group developed the significant intestinal lesions characterized by frothy contents, paleness, and thin intestinal walls. In this report we present an unusual case of runting stunting syndrome (RSS) with a history of high mortality and growth retardation in broiler chickens. We also make the first identification of CAstV and group A ARV in broiler chickens in Korea.

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.

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.

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.

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