新型冠状病毒肺炎感染者环境污染特征分析

Characteristics of SARS-CoV-2 contamination on inanimate surfaces in environment surrounding COVID-19 cases and asymptomatic infected individuals

目的了解新型冠状病毒肺炎(COVID-19)感染者的工作与居住环境污染特征,为疫情防控提供参考。方法2020年3—5月,在病例首次呼吸道样本检测新型冠状病毒(SARS-CoV-2)核酸阳性当日,对广州市越秀区报告的68例确诊病例和无症状感染者的工作与居住场所的物体表面进行涂抹采样,采用逆转录聚合酶链基因扩增方法(RT-PCR)开展病毒核酸检测。采用χ^(2)检验或Fisher′s确切检验法分析阳性率差异性,P<0.05为差异显著。结果环境物表共采样839份,消毒前阳性率为12.44%(54/434),明显高于消毒后阳性率0.49%(2/405)(χ^(2)=48.016,P<0.001)。消毒前,确诊病例、无症状感染者居住场所的物表阳性率无明显差异(χ^(2)=2.378,P=0.123);工作环境未检出阳性样本。将工作单位、居住场所根据用途分为公共区域、客厅/房间、厕所和厨房。其中厕所的阳性率最高(22.83%),其次为客厅/房间(14.80%)、公共区域(0.88%),而厨房未检出阳性样本。对11类物体样本分析,厕所用具的阳性率最高(23.75%)。结论新型冠状病毒确诊病例、无症状感染者活动区域均有不同程度的环境污染,其中厕所污染最为严重。

Objective To examine the characteristics of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2 contamination on inanimate surfaces in working and living places of the cases and asymptomatic individuals with coronavirus disease 2019(COVID-19) infection and to provide references for the prevention and control of the disease.Methods Inanimate surface swab specimens were collected in working and living places of 68 confirmed COVID-19 patients and asymptomatic cases on the day of the first positive detection of SARS-CoV-2 nucleic acid during March–May2020 in Yuexiu district of Guangzhou city. The specimens were detected for SARS-CoV-2 nucleic acid with real-time reverse transcriptase–polymerase chain reaction(RT-PCR). Chi-square test and Fisher′s exact test were used to analyze the difference in positive rates of the specimens. Results For a total of 839 specimens detected, the positive rate of SARS-CoV-2 nucleic acid was 12.44%(54/434) before terminal disinfections of ambient environments and the positive rate was significantly higher than that(0.49%, 2/405) after the terminal disinfections(χ^(2) = 48.016, P < 0.001). Before terminal disinfections, there was no difference in positive rates between the specimens collected in living environments of confirmed cases and asymptomatic individuals(χ^(2) = 2.378, P = 0.123). No positive specimen was detected in working environments.Among all the specimens collected in living environments, the positive rate(22.82%) was the highest for the specimens collected in bathrooms, followed by those collected in living rooms/bedrooms(14.80%), and public spaces(0.88%) and all specimens collected in kitchens were negative. For all the swab specimens of 11 kinds of appliances and articles, the positive rate was the highest(23.75%) for the specimens of toilet articles. Conclusion There are various extents of SARS-CoV-2 contamination on inanimate surfaces in working and living environments surrounding COVID-19 cases and asymptomatic infected individuals in Guangzhou city and the contamination is the worst in restroom environment.