Molecular detention and characterization of astrovirus and norovirus in cases of acute gastroenteritis in children hospitalized in the city of Rio De Janeiro
Acute viral gastroenteritis is responsible for significant morbidity and mortality among children and human astrovirus (HAstV) and norovirus (NV) have been identified increasingly worldwide as agents of those infections. The goals of this study were to determine the prevalence and molecular characterization of HAstV and NV by reverse-transcription polymerase chain reaction and partial sequencing in 318 fecal samples from children with acute gastroenteritis hospitalized in the municipality of Rio de Janeiro. The samples were obtained in 2004 from three hospitals (Hospital Jesus, Salles Neto and Souza Aguiar) and were previously investigated for the presence of Rotavirus (RV) and enteric Adenovirus (AdV). The viral RNA of NV and HAstV were detected in 20.4% (65) and 13.5% (43) of the samples, respectively. A total of 30 (9.4%) co-infections were identified, where 16 were by HAstV ? RV, 8 by NV ? RV, 3 by HAstV ? NV and 3 mixed infections by HAstV ? NV ?RV. The infections by HAstV and NV were detected in all age groups, with nearly 80% of the cases occurring in children until 2 years-old, with a higher percentage observed in children under 12 months-old. HAstV infections were more prevalent from March to May of that year, when temperature and rainfall are lower. On the other hand, NV cases were not only detected from March to May but also during September-October, suggesting an association of NV infections with dry season. Vomiting, cough and fever were the main clinical manifestations observed on those cases. The partial sequencing of the open reading frame 2 (ORF2) of 35 HAstV strains characterized 25 (71.4%) as genotype 1 (HAstV-1), 6 (17.1%) HAstV-2, 3 (8.6%) HAstV-8 and 1 (2.9%) HAstV-4. One out of 28 NV was characterized as belonging to Genogroup (G) I, Genetic Cluster 2 by the partial sequencing of the polymerase region gene whereas the others as GII. However, we were unable to cluster the latter G by using this region. The data obtained from this study have demonstrated the importance of NV and HAstV as agents causing acute infantile gastroenteritis and that the diagnostic implementation of those viruses could contribute with patients care, reducing the unnecessary use of antibiotics, mainly when the RV diagnostic is negative.
Advisor:Marize Pereira Miagostovich; José Paulo Gagliardi Leite
School:Faculdades Oswaldo Cruz
Source Type:Master's Thesis
Date of Publication:03/21/2006