A man in his eighties with gait problems and elevated CRP

• Published in: Tidsskrift for den Norske Lægeforening Vol. 141; no. 2021-14
• Main Authors: Berg, Åse, Doeland, Herman, Fardal, Hilde, Flørenæs, Even, Bjørnestad, Espen Øglænd, Lyngøy, Anita Sandmo, Syre, Heidi
• Format: Journal Article
• Language: Norwegian
• Published: 12.10.2021
• ISSN: 0807-7096
• DOI: 10.4045/tidsskr.21.0240

BACKGROUNDRapid detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in hospitals is essential for early isolation and treatment. However, false positive test results can have adverse consequences for patient safety. CASE PRESENTATIONA man in his eighties was admitted to hospital with fatigue and new-onset gait and balance difficulties, without fever or symptoms of focal infection, but with elevated C-reactive protein. On admission, he tested positive on screening for SARS-CoV-2 using a fully automated rapid reverse transcription polymerase chain reaction (RT-PCR) test. He was placed together with two patients with confirmed COVID-19 infection in cohort isolation. Due to very low exposure risk and nonspecific symptoms, the primary and multiple subsequent test swabs were analysed using RT-PCR analyses guided by laboratory personnel, and all gave negative results. The patient had several risk factors for developing severe COVID-19 illness, but fortunately he remained COVID-19 negative on repeated tests. INTERPRETATIONThe case presentation highlights the danger of false-positive SARS-CoV-2 test results, and the importance of interpreting a diagnostic test in the context of pretest probability and test accuracy. It also underlines the risk of using cohort isolation instead of individual isolation.