Performance of rapid tests for SARS-CoV-2 in children

Blog entry written on: Diagnostic accuracy of rapid point-of-care tests for diagnosis of current SARS-CoV-2 infections in children: a systematic review and meta-analysis, (bmjebm-2021-111828).

Authors: Naomi Fujita-Rohwerder, Lars Beckmann, Yvonne Zens, Arpana Verma


Performance of rapid tests for SARS-CoV-2 in children

There is no doubt that diagnostic testing represents an essential cornerstone of the global response to the current SARS-CoV-2 pandemic. Rapid point-of-care tests, particularly antigen tests, became widely available in Europe in autumn 2020 and complement testing with RT-PCR – the current standard method for diagnosing active infection with SARS-CoV-2 – where laboratory capacities are limited or when a short turnaround time is essential. However, speed comes at the price of lower diagnostic accuracy, most notably a lower diagnostic sensitivity, which increases the risk of missing cases, including those with pre-symptomatic infection who have yet to enter the most infectious period. 

Acknowledging the importance of reopening schools and kindergartens towards the end of the pandemic’s spring wave last year led to the implementation of antigen-based (self-)testing programmes in schools and kindergarten in many countries – despite lacking knowledge about how these tests perform in children. Thus, our systematic review aimed to identify, assess and summarise evidence on the diagnostic accuracy of rapid point-of-care tests to diagnose current SARS-CoV-2 infection in children under real-life conditions.

We identified 17 studies with a total of 6355 paediatric study participants that evaluated a total of eight different antigen tests from six different brands (last bibliographic search: May 7, 2021). The risk of bias was mostly unclear due to poor reporting. The pooled overall diagnostic sensitivity and specificity in children was 64.2% (95% CI 57.4% to 70.5%) and 99.1% (95% CI 98.2% to 99.5%), respectively. In symptomatic children, the pooled diagnostic sensitivity was 71.8% (95% CI 63.6% to 78.8%), and the pooled diagnostic specificity was 98.7% (95% CI 96.6% to 99.5%). The pooled diagnostic sensitivity in asymptomatic children was 56.2% (95% CI 47.6% to 64.4%), and the pooled diagnostic specificity was 98.6% (95% CI 97.3% to 99.3%).

While our results suggest that the performance of antigen tests for professional use in children is similar to what has been reported previously for adult populations, the minimum performance requirements defined by the WHO or different national regulatory agencies were met by none of the eight tests included in this systematic review. However, with almost 600 antigen tests that gained market access in Europe, we don’t know how most of these tests perform in real life – neither in adults nor in children. What we do know is that performance across tests varies broadly – even under ideal conditions in the laboratory and high viral load samples. Thus, it would be advisable to use only adequately validated tests, particularly within testing programmes, which is currently not the case. Sample collection in toddlers by laypersons or self-testing in schools performed by children is likely to influence the real-life test performance, but we don’t know to what extent. Also, diagnostic accuracy estimates reported in our study may not apply to the current omicron or future variants of SARS-CoV-2 or vaccinated children. 

It is important to note that diagnostic accuracy is only one of several factors that may affect the effectiveness of testing programmes. However, we hope that the results presented in this systematic review may support policymakers to develop and improve testing programmes in schools and kindergarten and encourage researchers to address the most relevant gaps in the evidence in order to support evidence-based decision-making.


Author

Image of blog post author, Naomi Fujita-Rohwerder. Naomi has a black bob and is wearing a purple shirt and black blazer.

Author: Naomi Fujita-Rohwerder, PhD, MPH

Institution: Institute for Quality and Efficiency in Health Care (IQWiG), Cologne, Germany

Conflicts of interest: None.


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