Universal Polymerase Chain Reaction and Antibody Testing Demonstrate Little to No Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 in a Rural Community

Background: Limited systematic surveillance for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the early months of the US epidemic curtailed accurate appraisal of transmission intensity Our objective was to perform case detection of an entire rural community to quantify SARS-CoV-2 transmission using polymerase chain reaction (PCR) and antibody testing Methods: We conducted a cross-sectional survey of SARS-CoV-2 infection in the rural town of Bolinas, California (population 1620), 4 weeks after shelter-in-place orders Participants were tested between April 20 and 24, 2020 Prevalence by PCR and seroprevalence from 2 forms of antibody testing were performed in parallel (Abbott ARCHITECT immunoglobulin [Ig]G and in-house IgG enzyme-linked immunosorbent assay) Results: Of 1891 participants, 1312 were confirmed Bolinas residents (>80% community ascertainment) Zero participants were PCR positive Assuming 80% sensitivity, it would have been unlikely to observe these results (P3 active infections in the community Based on antibody results, estimated prevalence of prior infection was 0 16% (95% credible interval [CrI], 0 02%-0 46%) The positive predictive value (PPV) of a positive result on both tests was 99 11% (95% CrI, 95 75%-99 94%), compared with PPV 44 19%-63 32% (95% CrI, 3 25%-98 64%) if 1 test was utilized Conclusions: Four weeks after shelter-in-place, SARS-CoV-2 infection in a rural Northern California community was extremely rare In this low-prevalence setting, use of 2 antibody tests increased seroprevalence estimate precision This was one of the first community-wide studies to successfully implement synchronous PCR and antibody testing, particularly in a rural setting Widespread testing remains an underpinning of effective disease control in conjunction with consistent uptake of public health measures © 2020 The Author(s) 2020 Published by Oxford University Press on behalf of Infectious Diseases Society of America