著者

Junna Oba Hiroaki Taniguchi Masae Sato Reika Takamatsu Satoru Morikawa Taneaki Nakagawa Hiromasa Takaishi Hideyuki Saya Koichi Matsuo Hiroshi Nishihara

出版者

The Keio Journal of Medicine

雑誌

The Keio Journal of Medicine (ISSN:00229717)

巻号頁・発行日

vol.70, no.2, pp.35-43, 2021 (Released:2021-06-25)

参考文献数

52

被引用文献数

2 21

---

The year 2020 will be remembered for the coronavirus disease 2019 (COVID-19) pandemic, which continues to affect the whole world. Early and accurate identification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is fundamental to combat the disease. Among the current diagnostic tests, real-time reverse transcriptase–polymerase chain reaction (RT-qPCR) is the most reliable and frequently used method. Herein, we discuss the interpretation of RT-qPCR results relative to viral infectivity. Although nasopharyngeal swab samples are often used for RT-qPCR testing, they require collection by trained medical staff. Saliva samples are emerging as an inexpensive and efficient alternative for large-scale screening. Pooled-sample testing of saliva has been applied for mass screening of SARS-CoV-2 infection. Current policies recommend isolating people with borderline cycle threshold (Ct) values (35<Ct <40), despite these Ct values indicating minimal infection risk. We propose the new concept of a “social cut-off” Ct value and risk stratification based on the correlation of Ct with infectivity. We also describe the experience of RT-qPCR screening of saliva samples at our institution. It is important to implement a scientific approach to minimize viral transmission while allowing economic and social activities to continue.