Lack of Prognostic Value of SARS-CoV2 RT-PCR Cycle Threshold in the Community

Infect Dis Ther. 2022 Feb;11(1):587-593. doi: 10.1007/s40121-021-00561-0. Epub 2021 Nov 11.

Abstract

The immense impact of the COVID-19 pandemic on health systems has motivated the scientific community to search for clinical prognostic factors for SARS-CoV-2 infection. Low cycle threshold values (Ct) of diagnostic real-time RT-PCR assays in hospitalized patients have been associated with a poor prognosis in several studies, whereas other studies did not find this association. We explored whether SARS-CoV-2 Ct values at diagnosis were associated with a poor outcome (admission to hospital and death) in 604 community patients diagnosed at primary health centers. Although lower Ct values were found in patients who died of COVID-19, the Ct value was not significantly associated with a worse outcome in a multivariate analysis, while age remained an independent prognostic factor. We did not find evidence to support the role of Ct values as a prognostic factor of COVID-19 in community cases.

Keywords: Community; Cycle threshold values; Outcome; RT-PCR; SARS-CoV-2.