The Centers for Disease Control has changed its definition of who is considered a “close contact” with someone who has coronvirus.
Previously, CDC defined close contact as being within 6 feet of an infected person for at least 15 minutes. That definition was used to determine when a person should be quarantined. Now, a “close contact” is defined as being within 6 feet of an infected person or persons for at least 15 minutes over a 24-hour period, indicating multiple brief encounters can contribute to spread of COVID-19.
While the CDC said data on the subject was limited, “15 cumulative minutes of exposure at a distance of 6 feet or less can be used as an operational definition (of a close contact) for contact investigation,” the guidance noted.
The change comes after a study looked at the spread of coronavirus at a Vermont prison when an employee contracted the virus after brief, close contact with infected incarcerated people that added up to more than 15 minutes over the course of an 8-hour shift.
Time of exposure does contribute to rate of transmission, however, CDC said.
“In general, the longer you are around a person with COVID-19 (even if they do not have symptoms), the more likely you are to get infected,” CDC said.
People who have come into close contact with a coronavirus-infected person are supposed to quarantine and be tested.
According to the CDC, the number of cases in the country are on an upswing with 70% of health districts experiencing an increase. The average daily case county in the past week was 13% higher than the previous 7 days, CDC said.