key: cord-0808392-07ntm1i5
authors: Hyde, B. L.; Berke, E.; Verma, P.
title: Pooled Sample Testing for SARS-CoV-2
date: 2021-01-26
journal: nan
DOI: 10.1101/2021.01.22.21250339
sha: 04f9aec1403b2ee7b2bf83b79ac61cba816ba275
doc_id: 808392
cord_uid: 07ntm1i5

We tested an operationally efficient way to pool samples on a rapid, point-of-care PCR device and examined the limit of detection of SARS-CoV-2 for various pool sizes. Pooled testing maintained testing performance similar to individual sample PCR testing, offering the potential for scalable rapid testing at lower cost with less supplies.

maintained testing performance similar to individual sample PCR testing, offering the potential 10 for scalable rapid testing at lower cost with less supplies. CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted January 26, 2021. ; https://doi.org/10.1101/2021.01.22.21250339 doi: medRxiv preprint NOTE: This preprint reports new research that has not been certified by peer review and should not be used to guide clinical practice. Testing for SARS-CoV-2 Using a Rapid RT-PCR COVID-19 Test (799   13 words) 14 Given the often asymptomatic presentation of COVID-19 and the potential for viral spread 15 before the onset of symptoms, reliable and repeatable testing is necessary to slow the pandemic. 16 New models of testing are required that can be self-administered, offer rapid results, and be 17 deployed in a variety of settings. Pooled sampling allows for cost-effective testing at improved under an IRB approved protocol. We held testing events over the course of several weeks where 33 asymptomatic employees were tested. All participants validated they were not experiencing any 34 . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted January 26, 2021. ; https://doi.org/10.1101/2021.01.22.21250339 doi: medRxiv preprint symptoms at the time of testing using both a daily symptom-checking application, ProtectWell, 35 plus a symptom check at time of testing. 36 We determined pool sizes based on the number of participants and the number of swabs each 37 participant provided, using a convenience sample approach. Participants provided 1-3 self- (Table 1) . For pools larger than 15 participants, the device was less consistent unless 53 the viral copies/mL were increased. However, at these large pool sizes the device detected 54 presence of virus at 9,483 viral copies per milliliter-lower than the limit of detection for many 55 . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted January 26, 2021. ; https://doi.org/10.1101/2021.01.22.21250339 doi: medRxiv preprint COVID-19 tests approved by the FDA , and in the performance range of some approved RT-56 PCR methods. 57 We created one additional pool with a known positive participant's sample combined with 14 58 other participants who were known negative. This pool was positive. The positive participant 59 was 12 days from exposure and substantially recovered from COVID-19. Interestingly, the 60 individual's sample was read as negative on a BioRad PCR machine, which has a published limit 61 of detection of 10,000 viral copies/mL.

This study validates that pooled testing is a compelling way to increase testing capacity while 64 still using high performance testing technology. Further analysis is needed to clearly define the 65 limit of detection in pools greater than 15 participants.

This study had several limitations. Pool sizes were opportunistic rather than formulaic. In most 67 pools, positive control was added via a pipette to ensure exact measurements, but in a few 68 limited cases the amount of positive control was approximated.

While the dilution buffer can preserve a sample for approximately two hours before degrading, 70 in a few cases the sample may have been processed up to an hour after collection (most samples 71 were processed in 30 minutes or less). Our observations support that testing as soon as possible 72 after introduction into the dilution buffer increases the performance of the test, particularly in 73 detecting low viral loads in larger pools.

. CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted January 26, 2021. ; https://doi.org/10.1101/2021.01.22.21250339 doi: medRxiv preprint Despite these limitations, this work demonstrates the potential of pooled testing with pool sizes 75 of 15 more to improve operational efficiency while reducing cost and supplies and maintaining 76 testing performance similar to other PCR testing approaches. 

Koepsell 84 SA, Iwen PC. Assessment of specimen pooling to conserve SARS CoV-2 testing 85 resources

Pooling of samples for testing for SARS-CoV-2 in asymptomatic 88 people

CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted January 26, 2021. . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted January 26, 2021. ; https://doi.org/10.1101/2021.01.22.21250339 doi: medRxiv preprint