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

Ayesha Appa; Saki Takahashi; Isabel Rodriguez-Barraquer; Gabriel Chamie; Aenor Sawyer; Elias Duarte; Jill Hakim; Keirstinne Turcios; Joanna Vinden; Owen Janson; Aashish Manglik; Michael J Peluso; Steven G Deeks; Timothy J Henrich; Leonel Torres; Mary Rodgers; John Hackett; Charles Chiu; Diane Havlir; Bryan Greenhouse

doi:10.1093/ofid/ofaa531

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

Open Forum Infect Dis. 2020 Oct 30;8(1):ofaa531. doi: 10.1093/ofid/ofaa531. eCollection 2021 Jan.

Authors

Ayesha Appa¹, Saki Takahashi¹, Isabel Rodriguez-Barraquer¹, Gabriel Chamie¹, Aenor Sawyer¹, Elias Duarte¹, Jill Hakim¹, Keirstinne Turcios¹, Joanna Vinden², Owen Janson¹, Aashish Manglik¹, Michael J Peluso¹, Steven G Deeks¹, Timothy J Henrich¹, Leonel Torres¹, Mary Rodgers³, John Hackett³, Charles Chiu¹, Diane Havlir¹, Bryan Greenhouse^{1

4}

Affiliations

¹ University of California San Francisco, San Francisco, California, USA.
² University of California Berkeley, Berkeley, California, USA.
³ Abbott Laboratories, Abbott Park, Illinois, USA.
⁴ Chan Zuckerberg Biohub, San Francisco, California, USA.

Abstract

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 (P < .05) if there were >3 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.

Keywords: COVID-19; rural population; seroepidemiologic studies; severe acute respiratory syndrome coronavirus 2.

Grants and funding

K24 AI144048/AI/NIAID NIH HHS/United States