某外籍货轮进口冷冻海鲜新型冠状病毒污染状况及其装卸工人感染危险因素调查

Investigation of contamination of SARS-CoV-2 in imported frozen seafood from a foreign cargo ship and risk factors for infection in stevedores in Qingdao

目的调查青岛市俄罗斯籍货轮进口冷冻海鲜的污染状况,分析其装卸工人感染的危险因素。方法对进口冷冻海鲜采用“两阶段、全覆盖、混采”的方法采集样本分析其污染情况,采用实时荧光定量RT-PCR法进行新型冠状病毒(新冠病毒)核酸检测;设计统一的调查问卷,对71名装卸工人开展电话调查。调查对象分为2组:报告2例新冠病毒无症状感染者的工作班组(A组工人,23名);未报告新冠病毒感染者的工作班组(B组工人,48名)。采用Epi Info7.2软件分析装卸工人新冠病毒感染的相关危险因素。结果俄罗斯籍货轮的装卸货物全部为进口冷冻海鲜,货物的新冠病毒核酸阳性率为11.53%(106/919)。A组工人装卸的进口冷冻海鲜中,新冠病毒核酸阳性率为14.29%(70/490),明显高于B组工人的8.39%(36/429)(χ^(2)=7.79,P=0.01),且A组工人装卸的进口冷冻海鲜的新冠病毒载量明显高于B组(P<0.05),A组工人的个人防护和行为得分明显低于B组(P<0.05);装卸工人搬运过程有上厕所、吸烟、饭前未规范洗手的行为是新冠病毒感染的危险因素。结论该批俄罗斯进口冷冻海鲜存在新冠病毒污染,且污染分布不均匀,应加强进口冷链从业人员的职业个人防护及行为的监督和管理。建议海洋渔业部门建立从业人员及运输货物的“捕捞-运输-装卸”全程闭环监测管理体系。

Objective To investigate the contamination status of SARS-CoV-2 in imported frozen seafood from a Russia cargo ship in Qingdao and to analyze the risk factors for infection in local stevedores.Methods The method of"two-stage,full coverage and mixed sampling"was used to collect the seafood packaging samples for the nucleic acid detection of SARS-CoV-2 by real-time fluorescent quantitative RT-PCR.A unified questionnaire was designed to investigate 71 stevedores in two shifts through telephone interview.The stevedores were divided into two groups,with 23 in the shit with two infections was group A and 48 in the shift without infection was group B.Software Epi Info7.2 was used to identify the risk factors for SARS-CoV-2 infections in the stevedores.Results In the frozen seafood from a Russia cargo ship,the total positive rate of SARS-CoV-2 nucleic acid in the frozen seafood was 11.53%(106/919).The positive rate of SARS-CoV-2 nucleic acid in the frozen seafood unloaded by group A(14.29%,70/490)was significantly higher than that in the frozen seafood unloaded by group B(8.39%,36/429)(χ^(2)=7.79,P=0.01)and the viral loads detected in the frozen seafood unloaded by group A were higher than those detected in the frozen seafood unloaded by group B.The scores of personal protection and behaviors in the stevedores in group A were significantly lower than those in group B(P<0.05),and toilet use,smoking and improper hand washing before meals were the risk factors for the infection.Conclusions The imported frozen seafood was contaminated by SARS-CoV-2 and the contamination distribution was uneven.Supervision and management of personal occupational protection and behaviors of workers engaged in imported frozen food transportation should be strengthened.It is suggested that a closed-loop monitoring and management system for the whole process of"fishing-transport-loading/unloading"should be established by marine fishery authority.