Evaluation of self-administered antigen testing in a college setting

Abstract

Background The objective of our investigation was to better understand barriers to implementation of self-administered antigen screening testing for SARS-CoV-2 at institutions of higher education (IHE). Methods Using the Quidel QuickVue At-Home COVID-19 Test, 1347 IHE students and staff were asked to test twice weekly for seven weeks. We assessed seroconversion using baseline and endline serum specimens. Online surveys assessed acceptability. Results Participants reported 9971 self-administered antigen test results. Among participants who were not antibody positive at baseline, the median number of tests reported was eight. Among 324 participants seronegative at baseline, with endline antibody results and ≥ 1 self-administered antigen test results, there were five COVID-19 infections; only one was detected by self-administered antigen test (sensitivity = 20%). Acceptability of self-administered antigen tests was high. Conclusions Twice-weekly serial self-administered antigen testing in a low prevalence period had low utility in this investigation. Issues of testing fatigue will be important to address in future testing strategies.

Why Daily SARS-CoV-2 Nasal Rapid Antigen Testing Poorly Detects Infected and Infectious Individuals

“…This clinical sensitivity is consistent with another recent field evaluation of this ANS Ag-RDT when used for twice-weekly screening testing on a college campus. 23 It is also consistent with FDA 79 and CDC guidance 80 31,41,43,[47][48][49][50][51][52][53][54][55][56][57][58] in which, for some individuals, early viral loads rise gradually, resulting in detection of the infected individual several days earlier by a high-analytical-sensitivity test than by the Ag-RDT. This mechanism for missed detection by COVID-19 Ag-RDTs has been previously hypothesized.…”

“…This Ag-RDT is authorized and in use globally, 2 with performance for ancestral variants evaluated in several cross-sectional studies. 10,23,76,77 The manufacturer reports that this Ag-RDT has an LOD with >95% positivity at 1.91x10 4 TCID50/mL of commercial heatinactivated SARS-CoV-2 particles. 74 Conversion of TCID50/mL to viral load in copies/mL is not provided in the FDA documentation, and the manufacturer was unable to provide this value nor a lot number or certificate of analysis for the heat-inactivated particles.…”

“…7,8,[10][11][12][13][14][15][16][17][18] Further, Ag-RDTs are frequently used in unintended ways. 15,19 For example, although many Ag-RDTs are not authorized for asymptomatic use and/or have poor clinical sensitivity in asymptomatic populations [20][21][22][23] they are widely used for test-to-enter and serial-screening purposes. 14,21,24 One view of Ag-RDTs is that these tests (and molecular tests with low analytical sensitivity) can still prevent or mitigate SARS-CoV-2 outbreaks if they are used frequently.…”

“…7,8,10-18 Further, Ag-RDTs are frequently used in unintended ways. 15,19 For example, although many Ag-RDTs are not authorized for asymptomatic use and/or have poor clinical sensitivity in asymptomatic populations 20-23 they are widely used for test-to-enter and serial-screening purposes. 14,21,24…”

Laboratory Evaluation Links Some False-Positive COVID-19 Antigen Test Results Observed in a Field Study to a Specific Lot of Test Strips

“…COVID-19 Ag-RDT false-positive results have been reported in a number of contexts [ 18 , 25 , 26 ]. In a recent evaluation of the Quidel QuickVue At-Home OTC COVID-19 test in a college community [ 27 ], 8 of 11 participants with positive Ag-RDT results were found to be negative on RT-PCR testing within 24 hours. No definitive cause for these false-positive results was identified.…”