Norovirus detection and genotyping for children with gastroenteritis, Brazil.
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ABSTRACT:
SUBMITTER: Soares CC
PROVIDER: S-EPMC2828093 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Norovirus (NoV) is one of the most common causes of acute gastroenteritis in children and adults. To study the prevalence and genetic variability of NoV in children with acute gastroenteritis in São Paulo State, Brazil, we examined 234 stool samples from children with or without gastroenteritis during a 5-year period (1995 to 1999). NoV RNA was detected by reverse transcription-PCR and confirmed by DNA sequence analysis. We used two different oligonucleotide primer sets targeting the 3' end of the RNA polymerase gene (region B), as well a partial capsid region at the 3' end of the VP1 gene (region D). A total of 78 (33.3%) of the samples tested positive for NoV, and in region B, of the 66 strains sequenced, 4 (6.1%) belonged to GI, 52 (78.7%) belonged to GII, and five samples (7.6%) contained a mixture of the GI and GII genotypes. Phylogenetic analysis showed that the majority (40 of 66 [60.6%]) of the strains belonged to genotype GII.4. The nucleotide sequence identity of three strains was lower than 77.9% compared to a region B reference sequence database but showed 85.3 to 88.8% identity with GII.2 Melksham strain in region D, indicating the circulation of a possible recombinant NoV strain. One sample (GII.3) was sequenced only in region D. In conclusion, we have a total of 67 sequenced strains. This is the first report that describes the predominance of GII.4 NoV strains in children visiting the ambulatory of different hospitals in São Paulo State, Brazil, and we show that mixtures of different strains can be found in individual samples, including some possible new recombinant strains.
| S-EPMC1698321 | biostudies-literature
Project description:Norovirus (NoV) is a major cause of acute gastroenteritis (AGE) worldwide, especially in children under five years. Studies involving the detection and molecular characterisation of NoV have been performed in Brazil, demonstrating its importance as an etiological agent of AGE.The objectives of this study were to investigate the frequency of human NoV and to genotype the strains isolated from 0-14-year-old patients of AGE in Manaus, Brazil, over a period of two years.A total of 426 faecal samples were collected between January 2010 and December 2011. All samples were tested for the presence of NoV antigens using a commercial enzyme immunoassay kit. RNA was extracted from all faecal suspensions and reverse transcription-polymerase chain reaction (RT-PCR) for the NoV-polymerase partial region was performed as a trial test. Positive samples were then subjected to PCR with specific primers for partial capsid genes, which were then sequenced.NoV was detected in 150 (35.2%) faecal samples, for at least one of the two techniques used. NoV was detected in children from all age groups, with the highest positivity observed among the group of 1-2 years old. Clinically, fever was verified in 43% of the positive cases and 46.3% of the negative cases, and vomiting was observed in 75.8% and 70.8% cases in these groups, respectively. Monthly distribution showed that the highest positivity was observed in January 2010 (81.2%), followed by February and April 2010 and March 2011, when the positivity rate reached almost 50%. Phylogenetic analyses performed with 65 positive strains demonstrated that 58 (89.2%) cases of NoV belonged to genotype GII.4, five (7.7%) to GII.6, and one (1.5%) each to GII.7 and GII.3.This research revealed a high circulation of NoV GII.4 in Manaus and contributed to the understanding of the importance of this virus in the aetiology of AGE cases, especially in a region with such few studies available.
| S-EPMC5446227 | biostudies-literature
Project description:Norovirus is a leading cause of pediatric gastroenteritis. Understanding norovirus epidemiology is essential for reducing disease burden. We conducted a case-control study to describe the distribution, clinical features, and risk factors of norovirus gastroenteritis among children < 5 years of age in León, Nicaragua. Cases were children testing positive for norovirus and controls were children living in the cases' communities. Study staff interviewed mothers of enrolled cases and controls to obtain detailed exposure information including food, water, and sanitation sources; recent exposures; household characteristics; and handwashing practices. In addition, study staff requested stool samples to be tested for norovirus from select household members. We used descriptive statistics to understand the epidemiologic and clinical features of gastroenteritis episodes. To analyze potential risk factors, we used Firth's penalized logistic regression to estimate crude and adjusted odds ratios (ORs) and corresponding 95% confidence intervals (CIs). There were 102 children with gastroenteritis, 18 cases of norovirus and 31 controls. Norovirus cases occurred later in the year, corresponding to a delay in the rainy season. Cases were more likely to have a household member with norovirus in their stool as compared with controls [crude OR: 13.3 (95% CI: 2.5, 136.2) and adjusted OR: 11.5 (95% CI: 1.6, 223.2)]. In addition, alcohol-based hand sanitizer use among household members was reported for 10 (32%) of controls and but never for cases. Further research is needed to understand household transmission of norovirus in low- and middle-income countries and the potential impact of hand sanitizer use.
| S-EPMC5590576 | biostudies-literature
Project description:Background. Rotavirus (RV) is the commonest pathogen in the hospital and primary care settings, followed by Adenovirus (AV) and Norovirus (NV). Only few studies that assess the burden of RV gastroenteritis at the community level have been carried out. Objectives. To estimate incidence, disease characteristics, seasonal distribution, and working days lost by parents of RV, AV, and NV gastroenteritis leading to a family pediatrician (FP) visit among children < 5 years. Methods. 12-month, observational, prospective, FP-based study has been carried out using Pedianet database. Results. RVGE incidence was 1.04 per 100 person-years with the highest incidence in the first 2 years of life. Incidences of AVGEs (1.74) and NVGEs (1.51) were slightly higher with similar characteristics regarding age distribution and symptoms. Risk of hospitalisation, access to emergency room (ER), and workdays lost from parents were not significantly different in RVGEs compared to the other viral infections. Conclusions. Features of RVGE in terms of hospitalisation length and indirect cost are lower than those reported in previous studies. Results of the present study reflect the large variability of data present in the literature. This observation underlines the utility of primary care networks for AGE surveillance and further studies on community-acquired gastroenteritis in children.
| S-EPMC4738938 | biostudies-other
Project description: Not available
| S-EPMC3880795 | biostudies-literature
Project description:Noroviruses are recognized as one of the leading causes of viral acute gastroenteritis, responsible for almost 50% of acute gastroenteritis outbreaks worldwide. The positive single-strand RNA genome of noroviruses presents a high mutation rate and these viruses are constantly evolving by nucleotide mutation and genome recombination. Norovirus recombinant strains have been detected as causing acute gastroenteritis outbreaks in several countries. However, in Brazil, only one report of a norovirus recombinant strain (GII.P7/GII.20) has been described in the northern region so far. For this study, 38 norovirus strains representative of outbreaks, 11 GII.4 and 27 non-GII.4, were randomly selected and amplified at the ORF1/ORF2 junction. Genetic recombination was identified by constructing phylogenetic trees of the polymerase and capsid genes, and further SimPlot and Bootscan analysis of the ORF1/ORF2 overlap. Sequence analysis revealed that 23 out of 27 (85%) non-GII.4 noroviruses were recombinant strains, characterized as: GII.P7/GII.6 (n = 9); GIIP.g/GII.12 (n = 4); GII.P16/GII.3 (n = 4); GII.Pe/GII.17 (n = 2); GII.P7/GII.14 (n = 1); GII.P13/GII.17 (n = 1); GII.P21/GII.3 (n = 1); and GII.P21/GII.13 (n = 1). On the other hand, among the GII.4 variants analyzed (Den Haag_2006b and New Orleans_2009) no recombination was observed. These data revealed the great diversity of norovirus recombinant strains associated with outbreaks, and describe for the first time these recombinant types circulating in Brazil. Our results obtained in southern Brazil corroborate the previous report for the northern region, demonstrating that norovirus recombinant strains are circulating more frequently than we expected. In addition, these results emphasize the relevance of including ORF1/ORF2-based analysis in surveillance studies as well as the importance of characterizing strains from other Brazilian regions to obtain epidemiological data for norovirus recombinant strains circulating in the country.
| S-EPMC4846083 | biostudies-literature
Project description:BACKGROUND: Acute gastroenteritis is a serious cause of child mortality and morbidity in resource-limited countries. A viral etiology is most common, and rotavirus and norovirus are reported to be the leading causative agents. There are still few epidemiological data on the simultaneous occurrence of these viruses in Morocco. The aim of this study was to provide useful epidemiological data on the gastroenteritis associated with rotavirus and norovirus among children aged less than 5 years. METHODS: From January to December 2011, 335 samples were tested for rotavirus and norovirus using enzyme-linked immunosorbent assay, reverse-transcription-polymerase chain reaction (RT-multiplex PCR) and real-time RT-PCR. Partial sequences of the norovirus were phylogenetically analyzed to determine the genotype. RESULTS: The overall rates of rotavirus and norovirus infections were 26.6% and 16.1%, respectively. Mixed viral infections were detected in 9 of 335 stool specimens (2.7%).The most common genotype combination in the rotavirus strains was G1[P8] (51.7%), followed by G2[P4] (10.1%), G2[P8] (4.5%), G9[P8] (3.4%), G4[P8] (3.4%), and G1[P6] (2.3%). Among patients positive for norovirus, 42 (77.8%) tested positive for GII and 12 (22.2%) for GI. Thirty-three (78.6%) of the norovirus GII-positive cases were successfully characterized. Genotype GII.4 was the most prevalent (n?=?27; 81.8%), followed by GII.3 (n?=?2; 6.1%), GII.13 (n?=?2; 6.1%), GII.16 (n?=?1; 3%), and GII.17 (n?=?1; 3%). CONCLUSION: This study suggests that in Morocco, norovirus is the most frequent cause of acute gastroenteritis after rotavirus, but further enteric viruses need to be integrated in the surveillance system so that a conclusion could be drawn.
| S-EPMC4057912 | biostudies-literature
Project description:Of 237 children with acute gastroenteritis in Antananarivo, Madagascar, during May 2004-May 2005, 14 ( 6%) were infected with norovirus. Seasonality (November-December peak) was detected. Reverse transcription-PCR identified GII as the most common genogroup. GIs belonged to GI.1, GI.3, and GI.4. Noroviruses in Madagascar show extensive genetic diversity.
| S-EPMC2792859 | biostudies-literature
Project description:The distribution of norovirus (NoV) genogroup II in children < 5 years of age admitted to a south Indian hospital with diarrhea was investigated. Viral RNA extracted from 282 stool samples were screened for NoV GII and positive amplicons sequenced. Twenty-eight (9.9%) had NoV GII infection with a median age of 6 months, with more severe episodes of diarrhea among infected (median Vesikari score 13, interquartile range [IQR] 10-15) than children without infection (median score 10, IQR 8-13, P = 0.002). The study documents NoV GII infections as an important cause of gastroenteritis and the genetic diversity of circulating strains.
| S-EPMC3820314 | biostudies-literature
Project description:Human bocavirus (HBoV) was detected in 14 (2%) of 705 fecal specimens from Brazilian children with gastroenteritis. Coinfection with rotavirus, adenovirus, or norovirus was found in 3 (21.4%) HBoV-positive specimens. None of the HBoV-positive patients had respiratory symptoms.
| S-EPMC2878208 | biostudies-literature