Article COVID-19 CRU Healthy Volunteers Humans Phase I clinical trials Point-of-Care Systems Polymerase Chain Reaction SARS-CoV-2 SARS-CoV-2 testing Severe acute respiratory syndrome coronavirus 2 asymptomatic carrier clinical article clinical effectiveness clinical research controlled study coronavirus disease 2019 diagnosis disease transmission epidemic gold standard human hygiene infection risk isolation and purification nonhuman normal human organization and management pandemic patient safety