Research Institute of the McGill University Health Centre (Campbell, Menzies, Dion, Yansouni, Uppal); Faculty of Medicine (Campbell, Menzies, Yansouni), McGill University; McGill International TB Centre (Campbell, Menzies); J.D. MacLean Centre for Tropical Diseases (Yansouni), Montréal, Que.
CMAJ Open. 2022 May 10;10(2):E409-E419. doi: 10.9778/cmajo.20210290. Print 2022 Apr-Jun.
Essential workers are at increased risk for SARS-CoV-2 infection. We aimed to estimate the yield, acceptability and cost of systematic workplace-based testing of asymptomatic essential workers for SARS-CoV-2 infection.
From Jan. 27 to Mar. 12, 2021, we prospectively recruited non-health care essential businesses in Montréal, Canada, through email or telephone contact. Two trained mobile teams, each composed of 2 non-health care professionals, visited businesses. Consenting asymptomatic employees provided saline gargle samples under supervision. Samples were analyzed by means of reverse transcription polymerase chain reaction (RT-PCR). At businesses with outbreaks (≥ 2 participants with a positive result), we retested all participants with a negative result on initial testing. Our primary outcomes were yield (proportion of test results that were positive), acceptability (proportion of participants estimated to be present at the business who agreed to participate) and costs (including training, sample collection and analysis, and communicating results). Our secondary outcome was identification of factors associated with a positive test result on multivariable logistic regression.
Of the 366 businesses contacted, 69 (18.8%) agreed to participate. Nineteen businesses (28%) were manufacturers or suppliers, 12 (17%) were in auto sales or repair, and 11 (16%) were in childcare; the corresponding number of employees was 1225, 242 and 113. The median number of participants per business was 13 (interquartile range [IQR] 8-22). Of an estimated 2348 employees on site, 2128 (90.6%) participated (808 [38.0%] female, median age 48 [IQR 37-57] yr). Of the 2626 tests performed, 53 (2.0%) gave a positive result. Self-reported nonwhite ethnicity (adjusted odds ratio [OR] 3.7, 95% confidence interval [CI] 1.4-9.9) and a negative SARS-CoV-2 test result before the study (adjusted OR 0.4, 95% CI 0.2-0.8) were associated with a positive test result. Five businesses were experiencing an outbreak; at these businesses, 40/917 participants (4.4%) had a positive result on the initial test. We repeated testing for employees with initially negative results at 3 of these businesses over 2-3 weeks: 8/350 participants (2.3%) had a positive result on the second test, and none had a positive result on the third and fourth tests; no employer reported new positive results after our final visit (up to Mar. 26, 2021). At the remaining 64 businesses, 1211 participants were tested once, of whom 5 (0.4%) had a positive result. The per-person RT-PCR cost was $34, and all other costs, $8.67.
On-site saline gargle sampling of essential workers for SARS-CoV-2 testing was acceptable and of modest cost, and appears most useful in the context of outbreaks. This sampling strategy should be evaluated further as a component of efforts to prevent SARS-CoV-2 transmission. PREPRINT: medRxiv - doi:10.1101/2021.05.12.21256956.
基本工作人员感染 SARS-CoV-2 的风险增加。我们旨在评估对无症状基本工作人员进行系统的工作场所 SARS-CoV-2 感染检测的收益、可接受性和成本。
从 2021 年 1 月 27 日至 3 月 12 日，我们通过电子邮件或电话联系前瞻性地招募了加拿大蒙特利尔的非医疗保健基本企业。由 2 名非医疗保健专业人员组成的 2 个训练有素的移动小组访问企业。同意的无症状员工在监督下提供盐水漱口样本。样本通过逆转录聚合酶链反应（RT-PCR）进行分析。在有暴发（≥ 2 名参与者检测结果阳性）的企业中，我们对所有初次检测结果阴性的参与者进行了复测。我们的主要结果是收益（检测结果阳性的比例）、可接受性（估计在企业中存在的参与者中同意参与的比例）和成本（包括培训、样本采集和分析以及结果沟通）。我们的次要结果是使用多变量逻辑回归识别与阳性检测结果相关的因素。
在联系的 366 家企业中，有 69 家（18.8%）同意参与。19 家企业（28%）为制造商或供应商，12 家（17%）为汽车销售或维修企业，11 家（16%）为儿童保育企业；相应的员工人数为 1225 人、242 人和 113 人。每家企业的平均参与者人数为 13 人（四分位距[IQR]8-22）。在估计的 2348 名现场员工中，有 2128 名（90.6%）参加了（808 名[38.0%]女性，中位年龄 48 [IQR 37-57] 岁）。进行了 2626 次测试，其中 53 次（2.0%）呈阳性。自我报告的非白人种族（调整后的优势比[OR]3.7，95%置信区间[CI]1.4-9.9）和研究前 SARS-CoV-2 检测结果为阴性（调整后的 OR 0.4，95%CI 0.2-0.8）与阳性检测结果相关。有 5 家企业正在经历暴发；在这些企业中，917 名参与者中有 40 名（4.4%）初次检测结果阳性。我们在其中 3 家企业对最初检测结果为阴性的员工进行了重复检测：在第二次检测中，有 8 名（2.3%）参与者检测结果阳性，在第三次和第四次检测中无人阳性；在我们的最后一次访问后，没有雇主报告新的阳性结果（截至 2021 年 3 月 26 日）。在其余 64 家企业中，对 1211 名参与者进行了一次检测，其中 5 名（0.4%）检测结果阳性。每份 RT-PCR 检测的费用为 34 美元，其他所有费用为 8.67 美元。
对基本工作人员进行现场盐水漱口 SARS-CoV-2 检测具有可接受性和适度成本，并且似乎在暴发情况下最有用。应进一步评估这种采样策略作为预防 SARS-CoV-2 传播努力的一部分。
