CDC COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Clin Infect Dis. 2021 Aug 2;73(3):e792-e798. doi: 10.1093/cid/ciab110.
Identifying asymptomatic individuals early through serial testing is recommended to control coronavirus disease 2019 (COVID-19) in nursing homes, both in response to an outbreak ("outbreak testing" of residents and healthcare personnel) and in facilities without outbreaks ("nonoutbreak testing" of healthcare personnel). The effectiveness of outbreak testing and isolation with or without nonoutbreak testing was evaluated.
Using published SARS-CoV-2 transmission parameters, the fraction of SARS-CoV-2 transmissions prevented through serial testing (weekly, every 3 days, or daily) and isolation of asymptomatic persons compared with symptom-based testing and isolation was evaluated through mathematical modeling using a Reed-Frost model to estimate the percentage of cases prevented (ie, "effectiveness") through either outbreak testing alone or outbreak plus nonoutbreak testing. The potential effect of simultaneous decreases (by 10%) in the effectiveness of isolating infected individuals when instituting testing strategies was also evaluated.
Modeling suggests that outbreak testing could prevent 54% (weekly testing with 48-hour test turnaround) to 92% (daily testing with immediate results and 50% relative sensitivity) of SARS-CoV-2 infections. Adding nonoutbreak testing could prevent up to an additional 8% of SARS-CoV-2 infections (depending on test frequency and turnaround time). However, added benefits of nonoutbreak testing were mostly negated if accompanied by decreases in infection control practice.
When combined with high-quality infection control practices, outbreak testing could be an effective approach to preventing COVID-19 in nursing homes, particularly if optimized through increased test frequency and use of tests with rapid turnaround.
通过连续检测尽早识别无症状个体，是控制养老院中 2019 年冠状病毒病（COVID-19）的推荐方法，无论是在暴发时（对居民和医护人员进行“暴发检测”），还是在无暴发时（对医护人员进行“非暴发检测”）。本研究评估了暴发检测和隔离（无论是否进行非暴发检测）的效果。
利用已发表的 SARS-CoV-2 传播参数，通过数学模型，使用 Reed-Frost 模型来评估每周、每 3 天或每天连续检测及隔离无症状者，相对于基于症状的检测和隔离，可分别减少多少 SARS-CoV-2 传播（即“有效性”），通过单独暴发检测或暴发加非暴发检测来预防多少比例的病例。同时还评估了实施检测策略时，隔离感染个体的有效性降低 10%（同时）对潜在效果的影响。
建模表明，暴发检测每周进行一次且检测结果在 48 小时内返回，可预防 54%（每周检测，48 小时内返回结果）至 92%（每天检测，即时获得结果，50%相对敏感性）的 SARS-CoV-2 感染；增加非暴发检测可预防高达 8%（取决于检测频率和周转时间）的 SARS-CoV-2 感染。然而，如果同时降低感染控制实践，非暴发检测的额外好处则大部分被抵消。
当与高质量的感染控制实践相结合时，暴发检测可能是预防养老院中 COVID-19 的有效方法，尤其是通过增加检测频率和使用快速周转的检测方法进行优化。
