Under half of COVID-19 patients know their infection source, studies showYesterday, Morbidity and Mortality Weekly Report (MMWR) published studies showing that only 46% of COVID-19 patients reported recent contact with an infected person and that only 27% did so in Colorado.In the first study, researchers from the Centers for Disease Control and Prevention (CDC) conducted a telephone survey of 350 COVID-19 outpatients and inpatients at 11 US academic medical centers from Apr 15 to May 24.Of the 46% of participants who reported recent exposure to the coronavirus, 45% said that they had contact with an infected family member, while 34% said they had been exposed to an infected coworker.