Department of Clinical Laboratory, Jiaozhou Central Hospital, 29 Xuzhou Road, Qingdao, Shandong, 266300, P.R. China.
Department of Clinical Laboratory, Jinan Second Peoples' Hospital, 148 Jingyi Road, Jinan, Shandong, 250000, P.R. China.
BMC Infect Dis. 2023 Sep 12;23(1):595. doi: 10.1186/s12879-023-08519-y.
Although many studies on asymptomatic norovirus infection in outbreaks have been conducted globally, structured data (important for emergency management of outbreaks) on the prevalence of this epidemic are still not available. This study assessed the global prevalence of asymptomatic norovirus infection in outbreaks.
We identified publications on asymptomatic infections from norovirus outbreaks by searching the PubMed, Embase, Cochrane Library, Medline, and Web of Science databases and screening references from the articles reviewed. Prevalence of asymptomatic norovirus infection in outbreaks was employed as the primary summary data. The random-effects model of the meta-analysis was fitted to generate estimates of the prevalence in the overall and subgroup populations.
In total, 44 articles with a sample size of 8,115 asymptomatic individuals were included. The estimated pooled prevalence of asymptomatic norovirus infection in outbreaks was 21.8% (95%CI, 17.4-27.3). The asymptomatic prevalence of norovirus GII (20.1%) was similar to that of GI (19.8%); however, the proportion prevalence of asymptomatic individuals involved in the former (33.36%) was significantly higher than that of in the latter (0.92%) and the former (93.18%) was reported much more frequently than the latter (15.91%) in the included articles. These studies had significant heterogeneity (I = 92%, τ = 0.4021, P < 0.01). However, the source of heterogeneity could not be identified even after subgroup analysis of 10 possible influencing factors (geographical area, outbreak settings, outbreak seasons, sample types, norovirus genotypes, transmission routes, subjects' occupations, subjects' age, per capita national income, and clear case definition). Meta-regression analysis of these 10 factors demonstrated that the geographical area could be partly responsible for this heterogeneity (P = 0.012).
The overall pooled asymptomatic prevalence of norovirus in outbreaks was high, with genome II dominating. Asymptomatic individuals may play an important role in norovirus outbreaks. This knowledge could help in developing control strategies and public health policies for norovirus outbreaks.
尽管全球已经开展了许多关于暴发中无症状诺如病毒感染的研究，但关于该流行病的流行率的结构化数据（对暴发的紧急管理很重要）仍然不可用。本研究评估了全球暴发中无症状诺如病毒感染的流行率。
我们通过检索 PubMed、Embase、Cochrane 图书馆、Medline 和 Web of Science 数据库以及审查文章的参考文献，确定了关于诺如病毒暴发中无症状感染的出版物。采用暴发中无症状诺如病毒感染的流行率作为主要汇总数据。采用荟萃分析的随机效应模型生成总体和亚组人群流行率的估计值。
共纳入 44 篇文章，包含 8115 名无症状个体的样本量。暴发中无症状诺如病毒感染的估计总流行率为 21.8%（95%CI，17.4-27.3）。诺如病毒 GII 的无症状流行率（20.1%）与 GI 相似（19.8%）；然而，前者涉及的无症状个体的比例患病率（33.36%）明显高于后者（0.92%），并且前者（93.18%）的报告频率明显高于后者（15.91%）在纳入的文章中。这些研究具有显著的异质性（I=92%，τ=0.4021，P<0.01）。然而，即使对 10 个可能的影响因素（地理区域、暴发环境、暴发季节、样本类型、诺如病毒基因型、传播途径、研究对象的职业、研究对象的年龄、人均国民收入和明确的病例定义）进行亚组分析，也无法确定异质性的来源。对这 10 个因素进行的荟萃回归分析表明，地理区域可能是造成这种异质性的部分原因（P=0.012）。
暴发中诺如病毒的总体无症状流行率较高，以基因组 II 为主。无症状个体可能在诺如病毒暴发中发挥重要作用。这些知识可以帮助制定诺如病毒暴发的控制策略和公共卫生政策。
