Postgraduate Program in Virology, Evandro Chagas Institute. Ananindeua, Pará, Brazil.
Virology Section, Evandro Chagas Institute, Health Surveillance Secretariat, Brazilian Ministry of Health. Ananindeua, Pará, Brazil.
J Med Virol. 2017 Nov;89(11):1894-1903. doi: 10.1002/jmv.24812. Epub 2017 Jul 28.
Fecal specimens were collected during a longitudinal, community-based study in the city of Belém, North Brazil, that was conducted over 3 years (October 1982 to March 1986), in which 20 children were included from birth to 3 years of age. A total of 229 fecal samples were screened by real time RT-PCR targeting the junction region (ORF 1/2) of the norovirus (NoV) genome. NoV-positive samples were subjected to PCR and sequencing of the viral polymerase (ORF1) and viral protein 1 (VP1) genes (ORF2). The junction region was also sequenced to assess for recombination when ORF1 and ORF2 genotyping results were dissimilar. Samples classified as GII.P4/GII.4 were further characterized by sequencing the P2 subdomain of the viral capsid to determine possible alterations. An overall positivity of 16.1% (37/229) was observed, including GI (16.2%-6/37) and GII (83.8%-31/37) genogroups. Cases of NoV reinfection in at least 2-month intervals were observed, and 12 children developed at least one case of asymptomatic NoV infection. In total, 48.6% (18/37) NoV-positive samples were subjected to nucleotide sequencing analysis targeting the following polymerase genes: GI.P3 (n = 1), GII.Pa (n = 1), GII.Pc (n = 1), GII.P4 (n = 5), GII.P6 (n = 5), GII.P7 (n = 3), GII.P12 (n = 1), and GII.P22 (n = 1). For the VP1 gene, characterization was performed in 14 (77.8%) samples: GI.3 (n = 1), GII.2 (n = 1), GII.4 (n = 4), GII.6 (n = 4), GII.7 (n = 1), GII.12 (n = 1), GII.14 (n = 1), and GII.23 (n = 1). Recombination events were confirmed in three cases (GII.P12/GII.2, GII.P7/GII.14, and GII.Pa/GII.12), and four samples genotyped as GII.P4/GII.4 were analyzed to identify variants. None had contemporary counterparts. Three children developed consecutive NoV infections by different genotypes. The present report documents the importance of NoV as a cause of childhood infection during a longitudinal study conducted more than 30 years ago.
在巴西北部贝伦市进行的一项为期 3 年（1982 年 10 月至 1986 年 3 月）的纵向社区研究中，我们收集了粪便标本，共有 20 名儿童从出生到 3 岁纳入研究。共有 229 份粪便样本通过实时 RT-PCR 针对诺如病毒（NoV）基因组的交界区（ORF1/2）进行了筛查。对 NoV 阳性样本进行病毒聚合酶（ORF1）和病毒蛋白 1（VP1）基因（ORF2）的 PCR 和测序。当 ORF1 和 ORF2 基因分型结果不同时，交界区也进行测序以评估重组。被分类为 GII.P4/GII.4 的样本通过对病毒衣壳的 P2 亚结构域进行测序进一步进行特征描述，以确定可能的改变。观察到总体阳性率为 16.1%（37/229），包括 GI（16.2%-6/37）和 GII（83.8%-31/37）基因型。观察到至少 2 个月间隔的 NoV 再感染病例，12 名儿童发生至少 1 次无症状 NoV 感染。共有 48.6%（18/37）的 NoV 阳性样本进行了针对以下聚合酶基因的核苷酸测序分析：GI.P3（n=1）、GII.Pa（n=1）、GII.Pc（n=1）、GII.P4（n=5）、GII.P6（n=5）、GII.P7（n=3）、GII.P12（n=1）和 GII.P22（n=1）。对于 VP1 基因，在 14 个（77.8%）样本中进行了特征描述：GI.3（n=1）、GII.2（n=1）、GII.4（n=4）、GII.6（n=4）、GII.7（n=1）、GII.12（n=1）、GII.14（n=1）和 GII.23（n=1）。在三个病例中证实了重组事件（GII.P12/GII.2、GII.P7/GII.14 和 GII.Pa/GII.12），并对四个基因型为 GII.P4/GII.4 的样本进行了分析以识别变体。没有当代的对应物。三个孩子发生了不同基因型的连续 NoV 感染。本报告记录了在 30 多年前进行的纵向研究中，NoV 作为儿童感染病因的重要性。
