Test, trace, isolate: evidence for declining SARS-CoV-2 PCR sensitivity in a clinical cohort

Real-time reverse transcription-polymerase chain reaction (RT-PCR) on upper respiratory tract (URT) sam-ples is the primary method to diagnose SARS-CoV-2 infections and guide public health measures, with a sup-portive role for serology. We reinforce previous findings on limited sensitivity of PCR testing, and solidify this fact by statistically utilizing a firm basis of multiple tests per individual. We integrate stratifications with respect to several patient characteristics such as severity of disease and time since onset of symptoms. Bayes-ian statistical modelling was used to retrospectively determine the sensitivity of RT-PCR using SARS-CoV-2 serology in 644 COVID-19-suspected patients with varying degrees of disease severity and duration. The sen-sitivity of RT-PCR ranged between 80% -95%; increasing with disease severity, it decreased rapidly over time in mild COVID-19 cases. Negative URT RT-PCR results should be interpreted in the context of clinical characteristics, especially with regard to containment of viral transmission based on 'test, trace and isolate'. Keywords: SARS-CoV-2, RT-PCR, serology, sensitivity, public health (c) 2021 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Automated summary

Real-time reverse transcription-polymerase chain reaction (RT-PCR) plays a key role in diagnosing and guiding SARS-CoV-2 infections, with sensitivity varying based on disease severity and duration. Bayesian statistical modeling is utilized to determine infection sensitivity, especially in the context of changing sensitivity in COVID-19 cases.