Núcleo de Doenças Infecciosas, Health Science Center, Federal University of Espírito Santo, Av Marechal Campos 1468, 29043-900 Maruipe, Vitória, ES, Brazil.
J Clin Virol. 2010 Jan;47(1):60-4. doi: 10.1016/j.jcv.2009.11.012. Epub 2009 Dec 8.
Noroviruses (NoVs) are a major etiological agent of sporadic acute gastroenteritis worldwide.
To detect, quantify and characterize genogroups and genotypes of NoVs in children with and without gastrointestinal symptoms.
NoVs were investigated by RT-PCR in a total of 319 fecal specimens from children up to three years old with (n=229) and without (n=90) acute diarrhea, between February 2003 and June 2004 in the emergency room in Vitória, Southeastern Brazil. NoVs were quantified by real-time PCR and genotyped.
NoVs were detected in 17% (40/229) and 13% (12/90) of symptomatic and asymptomatic children, respectively. Six NoV-rotavirus A mixed infections were observed. Fifty-one strains were characterized as NoV GII and one as GI. Twenty strains were characterized as GII/4 (9/13), GII/3 (1/13), GII/6 (2/13) and GII/14 (1/13) in symptomatic and GII/3 (6/7) and GII/8 (1/7) in asymptomatic children. The median RNA viral loads were 8.39 and 7.15log(10)copies/g of fecal specimens for symptomatic and asymptomatic children, respectively (p=0.011). NoV load was lower when it was present in a mixed infection with rotavirus A (p=0.0005).
This study demonstrates a diversity of NoV strains circulating in this geographic area, and reports GII/8 and GII/14 in the American Continent for the first time. In addition, it confirms GII/4 as the most prevalent genotype in symptomatic children and identified GII/3 in an important frequency, especially in asymptomatic children. Furthermore, preliminary results show that symptomatic patients present a viral load that is significantly greater than asymptomatic children (p=0.011).
诺如病毒（NoV）是全世界散发急性胃肠炎的主要病因。
检测、定量和分析有和无胃肠道症状的儿童中诺如病毒的基因群和基因型。
2003 年 2 月至 2004 年 6 月，在巴西东南部维多利亚市急诊室，共检测了 319 例年龄在 3 岁以下、有（n=229）和无（n=90）急性腹泻的儿童粪便标本，用 RT-PCR 检测诺如病毒，用实时 PCR 定量，对基因型进行鉴定。
有症状和无症状儿童的诺如病毒检出率分别为 17%（40/229）和 13%（12/90）。观察到 6 例诺如病毒-轮状病毒 A 混合感染。51 株鉴定为诺如病毒 GII，1 株鉴定为 GI。20 株在有症状儿童中鉴定为 GII/4（9/13）、GII/3（1/13）、GII/6（2/13）和 GII/14（1/13），在无症状儿童中鉴定为 GII/3（6/7）和 GII/8（1/7）。有症状和无症状儿童粪便标本的 RNA 病毒载量中位数分别为 8.39 和 7.15log(10)copies/g（p=0.011）。当诺如病毒与轮状病毒 A 混合感染时，病毒载量较低（p=0.0005）。
本研究显示了该地理区域流行的诺如病毒株的多样性，并首次在美洲大陆报告了 GII/8 和 GII/14。此外，它证实了 GII/4 是有症状儿童中最常见的基因型，并发现 GII/3 尤其是在无症状儿童中出现频率较高。此外，初步结果表明，有症状患者的病毒载量明显高于无症状儿童（p=0.011）。
