Background Norovirus is a leading cause of worldwide and nosocomial gastroenteritis. The study aim was to assess the utility of molecular epidemiology using full genome sequences compared to routine infection prevention and control (IPC) investigations. Methods Norovirus genomes were generated from new episodes of norovirus at a pediatric tertiary referral hospital over a 19-month period (n = 182). Phylogeny identified clusters of related sequences that were verified using epidemiological and clinical data. Results Twenty-four clusters of related norovirus sequences ("sequence clusters") were observed, including 8 previously identified by IPC investigations ("IPC outbreaks"). Seventeen sequence clusters (involving 77/182 patients) were corroborated by epidemiological data ("epidemiologically supported clusters"), suggesting transmission between patients. Linked infections were identified among 44 patients who were missed by IPC investigations. Thirty-three percent of norovirus sequences were linked, suggesting nosocomial transmission; 24% of patients had nosocomial infections from an unknown source; and 43% were norovirus positive on admission. Conclusions We show there are frequent introductions of multiple norovirus strains with extensive onward nosocomial transmission of norovirus in a pediatric hospital with a high proportion of immunosuppressed patients nursed in isolation. Phylogenetic analysis using full genome sequences is more sensitive than classic IPC investigations for identifying linked cases and should be considered when investigating norovirus nosocomial transmission. Sampling of staff, visitors, and the environment may be required for complete understanding of infection sources and transmission routes in patients with nosocomial infections not linked to other patients and among patients with phylogenetically linked cases but no evidence of direct contact.

中文翻译：

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使用全基因组序列的儿科医院中的诺如病毒传播动力学。

背景 诺如病毒是世界范围内和医院内胃肠炎的主要原因。该研究旨在与常规感染预防和控制 (IPC) 调查相比，使用全基因组序列评估分子流行病学的效用。方法 诺如病毒基因组是由一家儿科三级转诊医院在 19 个月内（​​n = 182）的新诺如病毒发作产生的。系统发育鉴定了使用流行病学和临床数据验证的相关序列簇。结果 观察到 24 个相关的诺如病毒序列簇（“序列簇”），包括先前由 IPC 调查确定的 8 个（“IPC 爆发”）。流行病学数据证实了 17 个序列集群（涉及 77/182 名患者）（“流行病学支持集群”），提示患者之间的传播。在 IPC 调查漏诊的 44 名患者中发现了相关感染。33% 的诺如病毒序列是相关联的，表明医院内传播；24% 的患者有不明来源的医院感染；43% 入院时诺如病毒呈阳性。结论 我们发现在一家儿科医院中经常引入多种诺如病毒株，这些病毒株在医院内广泛传播诺如病毒，隔离护理的免疫抑制患者比例很高。使用全基因组序列的系统发育分析在识别关联病例方面比经典 IPC 调查更敏感，在调查诺如病毒医院传播时应予以考虑。对工作人员、访客进行抽样，