Background: There are no reports regarding false positive reverse transcriptase polymerase chain reaction (RT-PCR) for novel coronavirus in preoperative screening.

Methods: Pre-operative patients had one or two nasopharyngeal swabs, depending on low or high risk of viral transmission. Positive tests were repeated.

Results: Forty-three of 52 patients required 2 or more pre-operative tests. Four (9.3%) had discrepant results (positive/negative). One of these left the COVID unit against medical advice despite an orbital abscess, with unknown true disease status. The remaining 3 of 42 (7.1%) had negative repeat RT-PCR. Although ultimately considered false positives, one had been sent to a COVID-unit postoperatively, and two had urgent surgery delayed. Assuming negative repeat RT-PCR, clear chest imaging, and lack of subsequent symptoms represent the "gold standard”, RT-PCR specificity was 0.97.

Conclusions: If a false positive is suspected, we recommend chest computed tomography and repeat RT-PCR. Validated immunoglobulin testing may ultimately prove useful.