Sample Pooling as a Strategy to Detect Community Transmission of SARS-CoV-2

Abstract

This study describes findings of novel coronavirus testing on pooled nasopharyngeal and bronchoalveolar lavage samples taken from patients who had negative results by routine respiratory virus testing to see if pooling samples could increase testing throughput and efficiency and facilitate early detection of community COVID-19 transmission.

Figure 1.. Number of Samples Screened for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)

Testing was performed by pooled sample screening at the Stanford Health Care Clinical Virology Laboratory over a 9-week period (January 1, 2020-February 26, 2020). Each pool included 9 to 10 individual samples that tested negative for other respiratory viruses. The number of SARS-CoV-2 samples, listed for weeks 1 through 9, were 96, 404, 444, 410, 469, 347, 330, 280, and 108. A total of 292 pools composed of 2888 individual samples were screened.

Figure 2.. Cumulative Number of Positive Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Samples

Two positive samples were identified through pooled screening during week 8. Week 9 indicates the cumulative number for the screening period. See Figure 1 caption for testing details.