Sample pooling: strain or solution?

Grobe, Nadja; Cherif, Alhaji; Wang, Xiaoling; Dong, Zijun; Kotanko, Peter

BACKGROUND Pool testing strategies combine samples from multiple people and test them as a group. A pool testing approach may shorten the screening time and increase the test rate during times of limited test availability and inadequate reporting speed. Pool testing has been effectively used for a wide variety of infectious disease screening settings. Historically, it originated from serological testing in syphilis. During the current COVID-19 pandemic pool testing is considered across the globe to inform opening strategies and monitor infection rates after interventions were implemented. OBJECTIVES This narrative review aims to provide a comprehensive overview of the global efforts to implement pool testing, specifically for screening of COVID-19. SOURCES Data were retrieved from a detailed search for peer-reviewed articles and preprint reports using Medline/PubMed, medRxiv, Web of Science, and Google up to March 21, 2021, using search terms "pool testing", "viral", "serum", "SARS-CoV-2", "COVID-19". CONTENT This review summarizes the history and theory of pool testing. We identified numerous peer-reviewed articles that describe specific details and practical implementation of pool testing. Successful examples as well as limitations of pool testing, in general and specifically related to the detection of SARS-CoV-2 RNA and antibodies, are reviewed. While promising, significant operational, pre-analytical, logistical, and economic challenges need to be overcome to advance pool testing. IMPLICATIONS The theory of pool testing is well understood and numerous successful examples are available from the past. Operationalization of pool testing requires sophisticated processes that are adopted to the local medical circumstances. Special attention needs to be paid to sample collection, sample pooling, and strategies to avoid re-sampling.