Fralick Michael, Moggridge Jason A, Wiebe Makenna, Castellani Lucas, McGeer Allison, Feenstra Bryan, Hinz Aaron, Hicks Alexandra M A, Hug Laura A, Wong Alex, Van Bakel Tamara, Abeygunawardena Sawith, Burhunduli Tasha, Mejbel Hebah S, Kassen Rees, Thampi Nisha, MacFadden Derek, Nott Caroline
Division of General Internal Medicine, Sinai Health System, Toronto, ON, Canada.
Department of Medicine, University of Toronto, Toronto, ON, Canada.
Infect Control Hosp Epidemiol. 2024 Sep 20;45(11):1-5. doi: 10.1017/ice.2024.121.
Recent work demonstrated that detection of SARS-CoV-2 on the floor of long-term care facilities is associated with impending COVID-19 outbreaks. It is unknown if similar results will be observed in hospitals.
Floor swabs were prospectively collected weekly from healthcare worker-only areas (eg, staff locker rooms) at two hospitals in Ontario, Canada for 39 weeks. Floor swabs were processed for SARS-CoV-2 using quantitative reverse-transcriptase polymerase chain reaction. Results were reported as percentage of positive floor swabs and viral copy number. Grouped fivefold cross-validation was used to evaluate model outbreak discrimination.
SARS-CoV-2 RNA was detected on 537 of 760 floor swabs (71%). At Hospital A, overall positivity was 90% (95% CI: 85%-93%; N = 280); at Hospital B, overall positivity was 60% (95% CI: 55%-64%; N = 480). There were four COVID-19 outbreaks at Hospital A and seven at Hospital B during the study period. The outbreaks consisted of primarily patient cases (ie, 140 patient cases and 4 staff cases). For every 10-fold increase in viral copies, there was a 22-fold higher odds of a COVID-19 outbreak (OR = 22.0, 95% CI 7.3, 91.8). The cross-validated area under the receiver operating curve for SARS-CoV-2 viral copies for predicting a contemporaneous outbreak was 0.86 (95% CI 0.82-0.90).
Viral burden of SARS-CoV-2 on floors, even in healthcare worker-only areas, was strongly associated with COVID-19 outbreaks in those hospital wards. Built environment sampling may support hospital COVID-19 outbreak identification, fill gaps in traditional surveillance, and guide infection prevention and control measures.
近期研究表明，在长期护理机构的地面检测到严重急性呼吸综合征冠状病毒2（SARS-CoV-2）与即将发生的冠状病毒病2019（COVID-19）疫情相关。在医院中是否会观察到类似结果尚不清楚。
在加拿大安大略省的两家医院，前瞻性地每周从仅医护人员使用的区域（如员工更衣室）采集地面拭子，持续39周。使用定量逆转录聚合酶链反应对地面拭子进行SARS-CoV-2检测。结果以地面拭子阳性百分比和病毒拷贝数报告。采用分组五重交叉验证来评估模型对疫情的判别能力。
在760份地面拭子中，检测到537份（71%）含有SARS-CoV-2核糖核酸（RNA）。在医院A，总体阳性率为90%（95%置信区间：85%-93%；n = 280）；在医院B，总体阳性率为60%（95%置信区间：55%-64%；n = 480）。在研究期间，医院A发生了4起COVID-19疫情，医院B发生了7起。疫情主要由患者病例组成（即140例患者病例和4例医护人员病例）。病毒拷贝数每增加10倍，COVID-19疫情发生的几率就高出22倍（比值比=22.0，95%置信区间7.3，91.8）。用于预测同期疫情的SARS-CoV-2病毒拷贝数的受试者操作特征曲线下交叉验证面积为0.86（95%置信区间0.82-0.90）。
即使在仅医护人员使用的区域，医院病房地面的SARS-CoV-2病毒载量也与COVID-19疫情密切相关。建筑环境采样可能有助于医院识别COVID-19疫情，填补传统监测的空白，并指导感染预防和控制措施。
