Katsunori Matsushita1, Daiichi Morii2, Saeko Nishida1, Hiroyuki Nishibayashi1, Shinichiro Zushi1, Jiro Kajikawa1, Nori Yoshioka3, Kazunori Tomono2, Sadayuki Doi1
Reverse-transcription polymerase chain reaction (RT-PCR) is the gold standard
for the diagnosis of coronavirus disease (COVID-19) in clinical practice. Falsepositive
results in RT-PCR assays may have serious implications for patients.
We aimed to investigate false-positive RT-PCR tests for severe acute respiratory
syndrome coronavirus 2 (SARS-CoV-2). We performed a retrospective case
series analysis. Among 46 patients who were diagnosed with COVID-19 by RTPCR
and admitted in our hospital during our study period, two patients were
scheduled for surgery and underwent RT-PCR testing for SARS-CoV-2 for routine
pre-operative screening. Subsequent RT-PCR retest and antibody test results for
SARS-CoV-2 were consistently negative for both patients. Although COVID-19
diagnostic tests are highly specific, false-positive results can occur if there is a
low pre-test probability. Our study emphasizes that clinicians should deal with
unexpected positive results with diligence and caution. We considered the
initial RT-PCR results of the two patients to be false positive. It is important to
interpret test results with caution, especially when patients are asymptomatic
with no exposure or circumstances that could increase infection-related risks
