2019—2023年上海市临港地区市售牡蛎中人源诺如病毒污染的调查研究

Investigation of human norovirus contamination in commercially sold oysters from the Lingang Area of Shanghai from 2019 to 2023

中文关键词:  诺如病毒  牡蛎  污染  基因型  新冠疫情  风险防控

英文关键词:norovirus  oysters  contamination  genotypes  COVID-19 pandemic  epidemiological trends

中文摘要:

      目的 为了检测和分析新冠疫情期间上海市市售牡蛎中诺如病毒( Norovirus，NoV) 的污染及基因型分布特点。方法 本研究自2019年10月至2023年4月从上海市水产市场随机采集545只牡蛎样本，利用巢式RT-PCR方法对样本中的诺如病毒进行检测分析。结果 发现牡蛎中诺如病毒污染的总阳性率为4.04%（22/545）。基因型分布上，共检出5种基因型：GI.3(n=5)，GI.4(n=3)，GII.17(n=3)，GII.3(n=9)，GII.4(n=4)，其中有4只牡蛎样本存在GI和GII型诺如病毒混合污染的现象。基因型丰度上，2019年检出以GI型为主，主要是GI.3；2020年至2022年检出以GII型为主，主要是GII.3和GII.4；2023年上半年检出GI、GII型都有，GII型偏多。季节上，每年的秋冬季牡蛎中NoV的检出率最高，与人群中诺如病毒的季节性暴发规律相吻合。总结 自新冠疫情暴发以来，上海市售牡蛎中诺如病毒检出率大幅下降，阳性检出率和基因类群变化与国外研究结果趋势一致，该研究结果不仅填补了国内在新冠疫情期间对牡蛎中诺如病毒监测的数据空缺，而且揭示了新冠病毒的传播也影响诺如病毒的富集、感染，同时还为为牡蛎的食用安全评估提供科学依据。

英文摘要:

      Objective To analyze the contamination and genotype distribution of human norovirus (NoV) in oyster samples during the COVID-19 pandemic. Methods In this study a total of 545 oyster samples were randomly collected from the Shanghai seafood market from October 2019 to April 2023. A nested RT-PCR combined with sequencing method was used to detect and identify the presence of human norovirus in these samples. Results The overall positive rate of human norovirus contamination in oysters was found to be 4.04% (22/545). As for genotype distribution, a total of five genotypes were identified: GI.3 (n=5), GI.4 (n=3), GII.17 (n=3), GII.3 (n=9), and GII.4 (n=4). Among these, four oyster samples exhibited mixed contamination with both GI and GII genotypes. As for genotype prevalence, GI was predominant in 2019, and especially GI.3; GII was predominant from 2020 to 2022, the main genotypes were GII.3 and GII.4; and in the first half of year 2023, both GI and GII were detected, and with a higher prevalence of GII. Seasonally, the detection rate of human norovirus in oysters was highest in the autumn and winter of each year, coinciding with the seasonal outbreak patterns of human norovirus in human populations. Conclusion Since the outbreak of the COVID-19 pandemic, the detection rate of norovirus in oysters sold in Shanghai has significantly decreased. The positive detection rate and the changes in genetic groups are consistent with trends observed in foreign studies. The results of study not only fill the gap in domestic data on the monitoring of human norovirus in oysters during the COVID-19 pandemic but also reveal that the spread of the coronavirus can affect the enrichment and infection of human norovirus. Furthermore, the findings provide a scientific basis for the assessment of the safety of oyster consumption.