食品和加工材料表面SARS-CoV-2存活规律研究

Persistence of SARS-CoV-2 on surfaces of food and processing materials

目的分析新型冠状病毒在不同食品和加工材料表面存活规律,为制定预防病毒通过食品和加工材料传播的防控措施和风险评估提供参考。方法将病毒培养物接种至常见进口食品和加工材料表面,使用荧光定量PCR方法测定在不同温度和时间条件下样本表面病毒核酸载量;使用半数组织培养感染剂量实验测定病毒滴度,观察病毒存活时间。使用线性回归模型计算病毒半衰期。结果食品和加工材料表面病毒核酸载量随时间下降,且温度越高病毒核酸载量下降越快。不同种类食品和加工材料表面病毒存活时间不同,室温条件下,猪肉和车厘子表面病毒存活24 h;其次为带鱼和鲜橙表面。加工材料表面病毒存活时间均较短,小于24 h。4℃条件下,病毒在猪肉表面至少存活1周,其次为车厘子和带鱼。-20℃条件下,病毒在猪肉和塑料包装表面的活性下降缓慢,8周后病毒滴度仍然较高,而在带鱼和纸板表面的活性下降明显。结论不同食品和加工材料表面的病毒核酸存续时间和存活规律不同,且温度越低病毒存活时间越长,应根据食品、加工材料类型,以及生产环境条件制定针对性预防和消毒措施。

Objective To analyze the survival law of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)on surfaces of different food and processed materials,so to provide reference for the formulation of prevention and control measures and risk assessment in the prevention of the virus spreading through food and processing materials.Methods The virus culture was inoculated on the surface of common imported food and processed materials,and the viral nucleic acid load on the surface under different temperature and at different time points were determined by fluorescence quantitative PCR method.The virus titers were determined by the median tissue culture infective dose(TCID50)assays and the survival time of the virus was observed.The half-lives of virus were calculated using linear regression models.Results The viral nucleic acids on the surface of food and processed materials decreased with time,and the higher the temperature,the faster the viral nucleic acid decreased.The survival time of the virus on the surface of various types of food and processed materials was different.The virus survived for 24 hours on the surface of pork and cherries,followed by the surface of hairtail and fresh orange under room temperature.The survival time of the virus on surfaces of processed material was shorter than 24 hours.At 4℃,the virus survived on the surface of pork for at least one week,followed by cherries and hairtail.The activity of virus on pork and plastic surface decreased slowly,and the virus titer remained high after 8 weeks while the activity decreased significantly in hairtail and cardboard at -20℃ condition.Conclusions The survival time of viral nucleic acid and virus on surfaces of various food and processing material were different.The lower the temperature,the longer the virus survived.Targeted preventive and disinfection measures should be formulated basing on different types of foods,processing materials and environmental conditions.