Evaluating the efficiency of specimen pooling for PCR‐based detection of COVID‐19

Wacharapluesadee, Supaporn; Kaewpom, Thongchai; Ampoot, Weenassarin; Ghai, Siriporn; Khamhang, Worrawat; Worachotsueptrakun, Kanthita; Wanthong, Phanni; Nopvichai, Chatchai; Supharatpariyakorn, Thirawat; Putcharoen, Opass; Paitoonpong, Leilani; Suwanpimolkul, Gompol; Jantarabenjakul, Watsamon; Hemachudha, Pasin; Krichphiphat, Artit; Buathong, Rome; Plipat, Tanarak; Hemachudha, Thiravat

In the age of a pandemic, such as the ongoing one caused by SARS‐CoV‐2, the world faces a limited supply of tests, personal protective equipment, and factories and supply chains are struggling to meet the growing demands. This study aimed to evaluate the efficacy of specimen pooling for testing of SARS‐CoV‐2 virus, to determine whether costs and resource savings could be achieved without impacting the sensitivity of the testing. Ten previously tested nasopharyngeal and throat swab specimens by real‐time PCR, were pooled for testing, containing either one or two known positive specimens of varying viral concentrations. Specimen pooling did not affect the sensitivity of detecting SARS‐CoV‐2 when the PCR cycle threshold (Ct) of original specimen was lower than 35. In specimens with low viral load (Ct>35), 2 out of 15 pools (13.3%) were false negative. Pooling specimens to test for COVID‐19 infection in low prevalence (≤1%) areas or in low risk populations can dramatically decrease the resource burden on laboratory operations by up to 80%. This paves the way for large‐scale population screening, allowing for assured policy decisions by governmental bodies to ease lockdown restrictions in areas with a low incidence of infection, or with lower risk populations. This article is protected by copyright. All rights reserved.