Validation of the Panbio COVID-19 Antigen Rapid Test (Abbott) to screen for SARS-CoV-2 infection in Sint Maarten: a diagnostic accuracy study

King, C.; Lista-de Weever, E.; Henry, M.; Steingrover, R.; Fleming, C.; Panneflek, R.; van Kampen, S.

Objectives: Control of the pandemic has required countries to look for other forms of tests besides the gold standard real-time polymerase chain reaction (RT-PCR). Rapid antigen tests (RAT), though less sensitive than RT-PCR, offer the possibility of rapid, inexpensive and early detection of the most infectious COVID-19 cases. Only very few studies have assessed the performance of the Abbott Panbio COVID-19 RAT among asymptomatic people or in Latin America. This study set out to validate this test among people attending the public test street in Sint Maarten, Dutch Caribbean. Methods: People of all ages were recruited from the public COVID-19 test street regardless of COVID-19 symptoms. They received a nasopharyngeal swab for the Abbott Panbio COVID-19 RAT and the RT-PCR Qtower. Diagnostic accuracy of the RAT was compared to the RT-PCR among the overall study population and for subgroups with/without symptoms, with/without close contact and different Ct values. Results: Using a RT-PCR Ct cut-off value of <33, 119 out of 1,411 people (8.4%) tested positive for SARS-CoV-2. Most were asymptomatic (59%). The overall sensitivity and specificity of the RAT was 84% (95% CI 76.2-90.1) and 99.9% (95% CI 99.6-100) respectively. The sensitivity reduced to 67.6% (95% CI: 49.5%, 82.6%) among people without symptoms, regardless of whether they were in close contact with a known COVID-19 case. Sensitivity reduced considerably with a Ct cut-off value of <35. Conclusions: The Abbott Panbio RAT is a valid and cheaper alternative to RT-PCR when used on symptomatic individuals among the general population. However, among asymptomatic people it should not be used as a stand-alone test and negative results should be confirmed with RT-PCR.