According to data collected on 1st February 2020 in 13 US academic medical centers % of clinicians who had previous evidence of COVID-19 infection – 6% Number of clinicians who had positive tests for COVID-19 but didn’t recall any viral symptoms – one-third of the total clinicians Number of clinicians who had positive tests for COVID-19 but didn’t suspect any viral illness – one-half of the total clinicians Number of clinicians who didn’t have positive results for COVID-19 – two-third of total clinicians