Dábilla Nathânia, Nunes Vieira Almeida Tâmera, Carvalho Rebouças Oliveira Anniely, Kipnis André, Neres Silva Thairiny, Souza Fiaccadori Fabíola, Teixeira de Sousa Teresinha, de Paula Cardoso Divina das Dôres, Souza Menira
Laboratory of Virology, Federal University of Goiás, Brazil.
Laboratory of Molecular Bacteriology, Federal University of Goiás, Brazil.
J Clin Virol. 2017 Feb;87:60-66. doi: 10.1016/j.jcv.2016.12.009. Epub 2016 Dec 21.
Noroviruses (NoVs) are an important cause of acute gastroenteritis (AGE), worldwide.
To evaluate the frequency, viral load and molecular profile of NoV in fecal and nasopharyngeal swab samples from hospitalized children, and to determine children's secretor status.
From May 2014 to May 2015, 219 children were included in the study, 96 with gastroenteric symptoms and 123 without gastroenteric symptoms. All fecal and nasopharyngeal swab samples were screened by TaqMan RT-qPCR duplex (GI/GII NoV) and quality samples were characterized by genomic sequencing.
Norovirus positivity rate in feces was 15.4% in asymptomatic and 18.8% in the symptomatic group. The median viral loads in feces were 2.69×10GC/g and 4.32×10GC/g from children with or without AGE symptoms, respectively. In nasopharyngeal swab samples, the NoV positivity was 11.4% in symptomatic children, with a median viral load of 2.20×10GC/mL and 6.5% in asymptomatic children, with an average viral load of 1.73×10GC/mL. In only two cases NoV was detected in both samples. A considerable genomic variability was observed in feces, with six genotypes being detected, as follows: GII.4, GII.6, GI.3 and GII.3, GI.2 and GI.5. Two GI.3 was detected in nasopharyngeal swab.
Our data reveal considerable NoV frequencies in both nasopharyngeal and fecal samples from symptomatic and asymptomatic children. Higher viral loads were detected in samples from AGE symptomatic children, when compared to asymptomatic children. High genomic variability was observed, with this being the first report of GI.5 NoV in Brazil and of GI.3 in nasopharyngeal swab samples.
诺如病毒（NoV）是全球急性胃肠炎（AGE）的重要病因。
评估住院儿童粪便和鼻咽拭子样本中诺如病毒的检出频率、病毒载量及分子特征，并确定儿童的分泌型状态。
2014年5月至2015年5月，219名儿童纳入本研究，其中96名有胃肠症状，123名无胃肠症状。所有粪便和鼻咽拭子样本均采用TaqMan RT-qPCR双链法（GI/GII诺如病毒）进行筛查，质量样本通过基因组测序进行特征分析。
无症状组粪便中诺如病毒阳性率为15.4%，有症状组为18.8%。有或无AGE症状儿童粪便中的病毒载量中位数分别为2.69×10GC/g和4.32×10GC/g。在鼻咽拭子样本中，有症状儿童的诺如病毒阳性率为11.4%，病毒载量中位数为2.20×10GC/mL；无症状儿童的阳性率为6.5%，平均病毒载量为1.73×10GC/mL。仅在两例样本中同时检测到诺如病毒。粪便中观察到相当大的基因组变异性，共检测到6种基因型，分别为：GII.4、GII.6、GI.3和GII.3、GI.2和GI.5。鼻咽拭子中检测到两株GI.3。
我们的数据显示，有症状和无症状儿童的鼻咽和粪便样本中诺如病毒检出频率相当高。与无症状儿童相比，AGE有症状儿童样本中的病毒载量更高。观察到高度的基因组变异性，这是巴西首次报告GI.5诺如病毒以及鼻咽拭子样本中GI.3诺如病毒。
