Routine blood tests do not detect novel coronaviruses. Routine blood tests are the most commonly used and easiest to perform. A routine blood test can be done by collecting blood from a fingertip, but it does not determine whether or not you are infected with novel coronavirus pneumonia. The purpose of the routine blood test is to determine whether there is inflammation or infection in the body, and also to determine whether there is a viral or bacterial infection. For example, blood tests for patients with novel coronavirus pneumonia are characterized by a normal or slightly decreased white blood cell count and a normal or decreased lymphocyte count. If these two points are met, a viral infection is likely. If the white blood cells are normal or slightly decreased, the lymphocytes are slightly decreased, and there is an epidemiologic history of fever and cough, novel coronavirus pneumonia is more likely, and it is recommended to go back for a throat swab nucleic acid test and a chest CT. If the chest CT shows ground glass shadow, it is consistent with novel coronavirus pneumonia, and then positive nucleic acid can confirm the diagnosis. Therefore, blood test is an important reference, but it cannot confirm the diagnosis of novel coronavirus pneumonia. Source: Dr. Yurai