United States
COVID-19, Coronavirus, SARS-CoV-2, COVID-19 diagnosis, rapid serology test, lateral-flow test, on-site testing, nursing homes, care homes, nursing facilities, asymptomatic COVID-19, false negative serology tests SARS-CoV2, false negative swab tests SARS-CoV-2, false negative RT-PCR test SARS-CoV-2, screening health care staff, screening nursing homes, protection of residents, SARS-CoV-2 diagnosis, COVID-19 symptoms, asymptomatic transmission, sensibility and sensitivity serology tests, sensibility and sensitivity RT-PCR