Rolling out COVID-19 antigen rapid diagnostic tests: the time is now.
Rolling out COVID-19 antigen rapid diagnostic tests: the time is now.
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DOI：
10.1016/s1473-3099(21)00152-3
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发表时间：
2021-08
期刊：
影响因子：
--
通讯作者：
Olliaro P
中科院分区：
文献类型：
--
作者：
Peeling RW;Olliaro P
COVID-19大流行一年来，关于检测如何结合其他措施（例如个人防护、物理距离和疫苗）来帮助遏制SARS-CoV-2传播，仍存在许多问题。在《柳叶刀传染病》一书中，雅普·布姆和同事们让我们看到了明智地使用诊断方法的可能性。分子检测是检测SARS-Cov-2感染的首选方法。但是，当能力受到限制，供应不一致，或在提供结果方面遇到延迟时，可以采用哪些替代技术和策略来检测COVID-19病例？Boum及其同事介绍了在症状出现后第一周、第二周和第三周内对有症状的COVID-19患者以及自愿接受检测或与COVID-19病例有接触的无症状患者进行PCR、基于抗原和基于抗体的快速诊断检测的结果。1与PCR相比，基于抗原的快速诊断试验的敏感性在症状发作后的前7天为80.0%（95%CI 71.0 ~ 88.0），在症状发作后的第2周为76.0%（59.0 ~ 88.0），在症状发作后的第3周降至19.0%（6.0 ~ 38.0）。相反，基于抗体的快速诊断测试的灵敏度随着疾病的持续时间而增加，从第一周的26.8%灵敏度（18.3 - 36.8）增加到症状发作后14天的76.4%（70.1 - 82.0）。为了改善有症状个体的病例检测，Boum及其同事利用他们的数据评估了一种诊断算法，该算法将抗原快速诊断测试与PCR确认抗原快速诊断测试阴性的样本相结合。1在第一周，60%的有症状的患者通过PCR检测为阳性，54%的有症状的患者通过基于抗原的快速诊断试验检测为阳性。这种方法的优点是它不仅高度敏感，（症状出现后0-7天为94%），在15分钟内为大多数患者提供结果，同时也节省了成本，将PCR检测成本降低了近50%（如果抗原快速检测可以检测出这一人群中54%的感染者，那么PCR检测只需要对剩下的46%的检测抗原阴性的人进行--与对每个人使用PCR相比，这节省了近50%的成本）。然而，在症状发作后的第一周后，尽管使用基于抗原的快速诊断检测提高了病例检测的灵敏度，但它受到低特异性的限制，这转化为需要PCR确认的大量假阳性样本。因此，时间就是一切：这种诊断算法降低的成本和更快的周转时间应该促使决策者鼓励人们更早地进行测试。早期诊断和隔离COVID-19患者以阻断传播仍然是控制大流行的关键策略。对于无症状个体的筛查，基于抗原的快速诊断检测的有用性取决于检测目的和待筛查人群中COVID-19的流行情况。对于那些可以返回学校，工作，参加群众集会或旅行的人进行分类，重要的是基于抗原的快速诊断测试具有高阴性预测值，因此那些测试阴性的人是真正的阴性。2当用于病例发现时，例如，在Boum及其同事的研究中，1被鉴定为基于抗原的快速诊断测试阳性的个体确实感染了SARS-CoV-2，这意味着高阳性预测值。Boum和同事1评估了一种结合抗原快速诊断测试筛查和...
A year into the COVID-19 pandemic, many questions remain regarding how testing, combined with other measures—eg, personal protection, physical distancing, and vaccines—could help curb SARS-CoV-2 transmission. In The Lancet Infectious Diseases, Yap Boum and colleagues1 give us a glimpse of what is possible when diagnostics are used wisely. Molecular testing is the method of choice for detecting SARS-Cov-2 infection. But when capacity is restricted, supplies are inconsistent, or delays are experienced in providing results, what alternative technologies and strategies can be adopted for COVID-19 case detection? Boum and colleagues presented the results of PCR, antigen-based, and antibody-based rapid diagnostic tests in individuals with symptomatic COVID-19 during the first, second, and third week after onset of symptoms, and in asymptomatic individuals who volunteered for testing or were contacts of COVID-19 cases. 1 Antigen-based rapid diagnostic test sensitivity was 80· 0%(95% CI 71· 0–88· 0) in the first 7 days after symptom onset and 76· 0%(59· 0–88· 0) in the second week post-symptom onset, dropping to 19· 0%(6· 0–38· 0) by week three, compared with PCR. Conversely, the sensitivity of antibody-based rapid diagnostic testing increased with duration of illness, from 26· 8% sensitivity (18· 3–36· 8) in week one to 76· 4%(70· 1–82· 0) 14 days after symptom onset. To improve case detection among symptomatic individuals, Boum and colleagues used their data to evaluate a diagnostic algorithm combining use of antigen rapid diagnostic tests with PCR confirmation of samples negative at antigen rapid diagnostic tests. 1 In week one, 60% of symptomatic patients tested positive by PCR and 54% of symptomatic patients tested positive by antigen-based rapid diagnostic test. The advantages to this approach are that it is not only highly sensitive (94% on days 0–7 after onset of symptoms), providing most patients with results in 15 min, but also cost-saving, reducing the cost of PCR testing by almost 50%(if antigen rapid tests can detect 54% of infected people in this population, then PCR testing is only needed for the remaining 46% of people who test antigen negative—compared with using PCR on everyone, this has a cost saving of nearly 50%). However, after the first week post-symptom onset, although use of antigen-based rapid diagnostic testing improves the sensitivity of case detection, it is limited by low specificity, which translates into high numbers of false-positive samples that require PCR confirmation. Therefore, timing is everything: the reduced costs and quicker turnaround time of this diagnostic algorithm should prompt decision makers to encourage people to present for testing earlier. Early diagnosis and isolation of individuals with COVID-19 to interrupt transmission remain a key strategy for pandemic control. For screening of asymptomatic individuals, the usefulness of antigen-based rapid diagnostic tests depends on both the purpose of testing and the prevalence of COVID-19 in the population to be screened. For triaging of those who can return to school, work, attend mass gatherings, or travel, it is important that antigen-based rapid diagnostic tests has a high negative predictive value, so that those who test negative are truly negative. 2 When used instead for case-finding among, for example, contacts of cases, as in Boum and colleagues’ study, 1 it is important that individuals identified as antigen-based rapid diagnostic test-positive are truly infected with SARS-CoV-2, meaning a high positive predictive value. Boum and colleagues1 evaluated an algorithm combining antigenbased rapid diagnostic test screening with …