False positive results in severe acute respiratory coronavirus 2 (SARS-CoV-2) rapid antigen tests for inpatients.

Severe acute respiratory syndrome coronavirus 2 rapid antigen detection (RAD) test kits are widely used as primary screening test in Japan because rapid diagnosis of coronavirus disease 2019 (COVID-19) is critical for infection control. We report cases with RAD test false-positive results in a ward for patients with disabilities. RAD tests potentially evoke hospital operational risk. It is desirable that performing PCR test appropriately when patients admitted to a medical treatment ward with COVID-19 symptoms instead of RAD test.