Combining PCR and CT testing for COVID

TL;DR

This paper demonstrates that combining rapid CT-scan screening with RT-PCR testing significantly reduces COVID-19 transmission and accelerates outbreak extinction compared to using PCR alone.

Contribution

It introduces a combined testing strategy utilizing CT-scans and PCR to enhance COVID-19 containment efforts.

Findings

50-fold reduction in cases after 60 days with combined testing

Effective reproduction rate R(t) decreases by 0.20

Rapid CT-scan screening enables faster isolation and contact tracing

Abstract

We analyze the effect of using a screening CT-scan for evaluation of potential COVID-19 infections in order to isolate and perform contact tracing based upon a viral pneumonia diagnosis. RT-PCR is then used for continued isolation based upon a COVID diagnosis. Both the low false negative rates and rapid results of CT-scans lead to dramatically reduced transmission. The reduction in cases after 60 days with widespread use of CT-scan screening compared to PCR by itself is as high as $50\times$, and the reduction of effective reproduction rate $R(t)$ is $0.20$. Our results imply that much more rapid extinction of COVID is possible by combining social distancing with CT-scans and contact tracing.