F2 and Recurrent upper respiratory tract infections: SARS-CoV-2 polymerase chain reaction (PCR) tests and laboratory tests, including international normalized ratio (INR), prothrombin time (PT), D-dimer, and activated thromboplastin time (APTT), were requested from 289 people presenting to the ED with symptoms of upper respiratory tract infection (URTI), such as cough, fever, and sore throat.