Pooled-Testing for SARS-CoV-2 Reverse Transcription Polymerase Chain Reaction (RT-PCR) in asymptomatic healthcare...

COVID-19 pandemic is a substantial challenge for healthcare systems. Severe acute respiratory syndrome coronavirus (SARS-CoV-2) reverse transcription-polymerase chain reaction (RT-PCR) tests are considered the gold standard technique for diagnosis of symptomatic and asymptomatic infectious viral carriers and for screening special or at-risk populations. The pooled testing procedure is commonly used to reduce the cost of screening a large number of individuals for infectious diseases. This work was conducted to verify the accuracy of the standard SARS COV-2 RT- real-time PCR kit for detecting a single positive sample in a pool of negative samples. Kit verification using negative and positive samples was performed for the selection of the target pool sizes. RNA extracts from 443 healthcare workers, after 15 days' rotation in EL-Raghy Isolation COVID-19 Hospital, Assiut University during the first outbreak of COVID-19 pandemic (the period from June to September 2020) were obtained and tested. Sixty-three different pool sizes (2, 3, 4, 5, 6, 7, 8, 9, and 10) were tested for the presence of SARS-CoV-2 using RT-qPCR. Of these, 53 pools (84.1%) were negatives and 10 pools (15.9 %) tested positive. The individual number of SARS- COV 2 RT-PCR tests used in different pool sizes was 40 tests. The total number of SARS- COV 2 RT-PCR test used in this study was 110 tests instead of 443 tests which reflect a decrease in cost up to 75.16%. In conclusion, the suggested pooling strategy can reduce testing loads which enable substantial savings in reagent costs, technical burden, and time to generate laboratory results.