1 in 2 COVID-19 Patients could not identify a person with COVID-19 with whom they had close contact in the last 2 weeks.

Read more here Characteristics of Adult Outpatients and Inpatients with COVID-19 : https://www.cdc.gov/mmwr/volumes/69/wr/mm6926e3.htm?s_cid=mm6926e3_e&deliveryName=USCDC_921-DM32007