Elliott J, Whitaker M, Bodinier B, et al. - The authors demonstrate that utilizing a combination of seven symptoms to determine test eligibility would maximize case detection rates in the community under testing capacity restrictions such as those encountered in England between June 2020 and January 2021. This has policy implications for countries with limited testing capacity. They discovered the same symptom set for anticipating B.1.1.7, which by April 2021 had become the predominant lineage in the UK, US, and many other countries worldwide.

• In the REal-time Assessment of Community Transmission-1 study, the authors collected throat and nose swabs with valid SARS-CoV-2 PCR test results from 1,147,370 volunteers aged 5 years and above (6,450 positive cases).

• In univariate analysis, all 26 surveyed symptoms were related to PCR positivity vs non-symptomatic people.

• In rounds 2–7 (June to December 2020), stability selection (1,000 penalized logistic regression models with 50% subsampling) among people reporting at least 1 symptom identified 7 symptoms as jointly and positively predictive of PCR positivity: loss or change of sense of smell, loss or change of sense of taste, pyrexia, new persistent cough, chills, appetite loss, and muscle aches.

• With an area under the curve (AUC) of 0.77, the resulting model (rounds 2–7) predicted PCR positivity in round 8.

• In round 8, the same 7 symptoms were chosen as jointly predictive of B.1.1.7 infection, though when comparing B.1.1.7 to wild type infection, new persistent cough and sore throat were more predictive of B.1.1.7 infection, whereas loss or change of sense of smell was more predictive of the wild type.