Supplementary Material for: National Weekly SARS-CoV-2 RT-PCR Screening of All Workers in Long-Term Care Facilities Associated with Decrease in Resident Mortality Rate

Introduction Outbreaks of COVID-19 in long-term care facilities (LTCFs) have resulted mainly from disease transmission by asymptomatic health care workers. This study examines whether routine screening tests carried out on health care workers can help in reducing COVID-19 outbreaks, morbidity, and mortality of LTCF residents. Methods The study followed a weekly, nationwide, government-funded screening program of LTCF personnel for SARS-CoV-2, by using reverse transcription polymerase chain reaction as the main testing technology. It included all residents and employees in Israeli LTCFs who were screened weekly during the second wave of COVID-19, during the time period between July 13, 2020, and November 21, 2020. Results During the study period, 1,107 LTCFs were screened on a weekly basis, including 62,159 HCWs and 100,046 residents. The program screened a median of 55,282 (Range 16,249, min 45,910, max 62,159) employees per week, 0.05-1.5% of which were positive for SARS-CoV-2. LTCF mortality in the first wave accounted for 45.3% of all COVID-19 deaths recorded nationally (252 of 556), and in the second wave this ratio was reduced to 30.3% (709 of 2,337) representing a reduction of 33.8% in expected mortality (P<0.001). A significant reduction was detected also in hospitalization rate (13.59% vs. 11.41%, p<0.001) and elder (≥75 years-old) mortality rate (52.89% vs. 41.42%, p<0.001). 214 outbreaks in the second wave were avoided by early identification of SARS-CoV-2 positive HCWs and successful prevention of subsequent infections in the facility. Conclusions and relevance Routine weekly SARS-CoV-2 RT-PCR testing of LTCF employees was associated with reduced national LTCF residents’ hospitalizations and mortality rate.

引言 长期护理机构（long-term care facilities, LTCFs）内的新冠疫情暴发主要源于无症状医护人员的疾病传播。本研究旨在评估针对医护人员开展的常规筛查，能否降低LTCF居住者的新冠疫情暴发风险、发病率与死亡率。

方法 本研究依托一项每周开展、全国覆盖且由政府资助的筛查项目，针对长期护理机构人员开展新型冠状病毒（SARS-CoV-2）检测，核心检测技术为逆转录聚合酶链反应（reverse transcription polymerase chain reaction）。研究纳入了2020年7月13日至2020年11月21日新冠疫情第二波期间，以色列所有接受每周筛查的长期护理机构的居住者与雇员。

结果 研究期间，共计对1107家长期护理机构开展每周筛查，涉及62159名医护人员（health care workers, HCWs）与100046名居住者。每周筛查的雇员人数中位数为55282人（区间范围16249至62159，最小值45910，最大值62159），其中0.05%~1.5%的检测结果为SARS-CoV-2阳性。第一波疫情期间，LTCF相关新冠死亡占全国总新冠死亡数的45.3%（556例中死亡252例）；第二波疫情期间该占比降至30.3%（2337例中死亡709例），预计死亡率较第一波降低33.8%（P<0.001）。住院率同样出现显著下降（13.59%相较11.41%，P<0.001），75岁及以上老年人的死亡率亦显著降低（52.89%相较41.42%，P<0.001）。通过早期识别SARS-CoV-2阳性医护人员并成功阻断机构内后续感染传播，第二波疫情期间共计避免214起疫情暴发事件。

结论与相关性 对LTCF雇员开展每周一次的常规SARS-CoV-2逆转录聚合酶链反应检测，与全国范围内LTCF居住者的住院率及死亡率降低显著相关。