Astrovírus infection in hospitalized children: molecular, clinical and epidemiological features

• Autor(a) principal: Siqueira, Jones Anderson Monteiro
• Data de Publicação: 2017
• Outros Autores: Oliveira, Darleise de Souza, Carvalho, Thaís Cristina Nascimento de, Portal, Thayara Morais, Justino, Maria Cleonice Aguiar, Silva, Luciana Damascena da, Resque, Hugo Reis, Gabbay, Yvone Benchimol
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Digital do Instituto Evandro Chagas (Patuá)
• Texto Completo: https://patua.iec.gov.br/handle/iec/2880
• topic: Astroviridae / patogenicidade; Gastroenterite; Mamastrovirus / patogenicidade; Diarreia; Região Amazônica (BR); Belém (PA)

Background: Astrovirus (HAstV) is a common viral pathogen that causes gastroenteritis worldwide. It is classified into eight classical human types (HAstV-1/8) and seven other less prevalent types, described as HAstV VA1, VA2, VA3, VA4, MLB-1, MLB-2 and MLB-3. During outbreaks, the elderly and children are the most affected, and the spread of the virus is associated with person-to-person contact, food ingestion and contaminated water. Objectives: The aim of the present study was to investigate the prevalence of infection and genetic diversity of HAstV strains. Samples were collected from children with acute gastroenteritis admitted to a large pediatric hospital during a surveillance period of three years (2008–2011) in Belém city, Pará State, Amazon Region, Northern Brazil. Study design: Screening and genotyping tests were conducted using RT-PCR to detect the classical and non-classical HAstV types using specific primers. A semi-nested RT-PCR protocol was developed to improve viral detection in samples with a low viral load. Results: The overall positivity observed in this study was 3.9% (19/483). The age distribution showed a high prevalence of positive cases in children under one year old (5.3%). We found vomiting associated with 75% of the positive cases, fever with 82.3%, and dehydration with 76.9%. Most patients with positive cases demonstrated two to five days of diarrhea, two to three episodes of vomiting during hospitalization, and three bowel movements per day. Co-infection with HAstV and norovirus was observed in three cases (15.8%), and no pattern of seasonality or any relationship between the HAstV positivity rate and climate variables was observed. Eighteen positive samples (94.7%–18/19) were genotyped based on the ORF 2 region, and the greatest prevalence was of HAstV-1a (66.6%–12/18), followed by HAstV-2 (22.2%–4/18, comprising two type-2b and two type-2c genotypes), HAstV-3c (5.6%–1/18) and HAstV-4c (5.6%–1/18). No non-classical types were detected in the clinical samples analyzed. Conclusions: The present study showed that although HAstV infections occur at low frequency, they are involved in severe pediatric cases of acute gastroenteritis presenting with a high diversity of strains, including the lineages 3c and 4c, which were never before detected in Brazil.