We report a case study of a COVID-19 patient whose PCR results fluctuated from detected to not detected over a period of 3 weeks depending on the PCR assay used and the challenge this presented to clinicians. This is the first report of the longitudinal assessment of a COVID-19 patient in Ireland who was followed up for 45 days since the first positive result. Our findings highlight the difficulty for clinicians in making a decision to move patients to a different ward or for discharge from hospital whilst adhering to initial recommendations published by the WHO to confirm clearance of the virus which was that the patient required to be clinically recovered and to have two negative RT-PCR results on sequential samples taken at least 24 hours apart. Furthermore, researchers have stressed the need for caution in interpreting any negative results of RT-PCR diagnostic tests as many factors can play a role in the accuracy of the results.
Key clinical message: This case report highlights that although in general PCR assays are able to detect SARS- CoV-2, the detection limits and the ability to differentiate between true negatives and positives at low RNA concentrations are variable between assays.
Published Date: 2021-05-03; Received Date: 2021-04-12