COVID-19 Ag Respi-Strip detects the presence of SARS-Cov-2 antigens in a nasopharyngeal swab in 15 minutes.
A multi-centre clinical study was performed based on tests direct from 328 nasopharyngeal swabs in three clinical laboratories.
Overall sensitivity was 57.6% whilst sensitivity on samples with Ct <22 was 95% and most importantly the positive predictive value was 98.7%.
The differing sensitivities should be interpreted with the view that many samples with a CT> 25 could be regard as false positives.
Results in 15 minutes from a throat swab.
No equipment required
As easy to use as a pregnancy test
COVID-19 testing and correlation with infectious virus, cycle thresholds, and analytical sensitivity. Spencer EA, Jefferson T, Heneghan C. https://www.cebm.net/study/covid-19-testing-and-correlation-with-infectious-virus-cycle-thresholds-and-analytical-sensitivity/Published on August 27, 2020
Evidence Summary The cultured specimens (from 161 cases with positive PCR) spanned a wide range of cycle threshold values reflecting different viral loads.
Infectious virus was associated with mean Ct values of 18.8 ± 3.4 (median 18.7)
Not obtaining infectious virus was associated with mean Ct values 27.1 ± 5.7 (median 27.5) (see the figure)
Samples with a Ct value below 23 yielded 91.5% of virus isolates. However, 29% of specimens that were negative for viral growth on VeroE6 cells were in the same Ct value range and 11.9% were below a Ct value of 20