SARS-CoV-2 detection in multi-sample pools in a real pandemic scenario: A screening strategy of choice for active surveillance

CASTELLARO AM; VELEZ P; GIAJ MERLERA G; RONDAN DUENAS J; CONDAT F; GALLARDO J; MAKHOUL A; CINALLI C; ROSALES CAVAGLIERI L; DI COLA G; SICILIA P; LOPEZ L; CRESPO P; FURLAN G; GATICA L; MIRO MS; MOTRICH RD; RACCA AC; REYNA L; BOCCO JL; BARBAS MG; CARDOZO DH; PISANO MB; RE V; BELAUS A; CASTRO GM

PLOS ONE

PUBLIC LIBRARY SCIENCE

Lugar: San Francisco; Año: 2022 vol. 17

1932-6203

ackground: The current COVID-19 pandemic has overloaded the diagnostic capacity of laboratories by the gold standard method rRT-PCR. This disease has a high spread rate and almost a quarter of infected individuals never develop symptoms. In this scenario, active surveillance is crucial to stop the virus propagation.Methods: Between July 2020 and April 2021, 11,580 oropharyngeal swab samples collected in closed and semi-closed institutions were processed for SARS-CoV-2 detection in pools, implementing this strategy for the first time in Córdoba, Argentina. Five-sample pools were constituted before nucleic acid extraction and amplification by rRT-PCR. Comparative analysis of cycle threshold (Ct) values from positive pools and individual samples along with a cost-benefit report of the whole performance of the results was performed.Results: From 2,314 5-sample pools tested, 158 were classified as positive (6.8%), 2,024 as negative (87.5%), and 132 were categorized as indeterminate (5.7%).