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

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.