Contribution of High Viral Loads, Detection of Viral Antigen and Seroconversion to Severe Acute Respiratory Syndrome Coronavirus 2 Infectivity.

Background: From a public health perspective, effective containment strategies for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) should be balanced with individual liberties.

Methods: We collected 79 respiratory samples from 59 patients monitored in an outpatient center or in the intensive care unit of the University Hospital Regensburg. We analyzed viral load by quantitative real-time polymerase chain reaction, viral antigen by point-of-care assay, time since onset of symptoms, and the presence of SARS-CoV-2 immunoglobulin G (IgG) antibodies in the context of virus isolation from respiratory specimens.