New guidance from the Centers for Disease Control and Prevention has expanded who should be considered a close contact of someone who tests positive for COVID-19.
Under the old guidelines, the definition of a close contact was someone who “was within 6 feet of an infected person for at least 15 minutes starting from 2 days before illness onset (or, for asymptomatic patients, 2 days prior to specimen collection) until the time the patient is isolated.”
The change in guidance, announced in a Wednesday CDC statement, is slight but suggests that far more people should be tested based on contact tracing.
According to the new CDC guidelines, a close contact is someone who spends 15 minutes or more with someone over the course of 24 hours. Previously, the guidance was restricted to 15 consecutive minutes. The CDC now advises anyone who had brief encounters with someone over the course of 24 hours that equal roughly 15 minutes to quarantine for two weeks.
The update follows results released Tuesday from a study involving a correctional facility employee in Vermont who was diagnosed with COVID-19 despite never having a 15-minute encounter with anyone who tested positive. Instead, “during his 8-hour shift on July 28, the correctional officer was within 6 feet of an infectious [incarcerated or detained person] an estimated 22 times while the cell door was open, for an estimated 17 total minutes of cumulative exposure,” according to the study.
“A primary purpose of contact tracing is to identify persons with higher risk exposures and therefore higher probabilities of developing infection, which can guide decisions on quarantining and work restrictions,” the study continued. “Although the initial assessment did not suggest that the officer had close contact exposures, detailed review of video footage identified that the cumulative duration of exposures exceeded 15 minutes.”
The study highlighted the importance of wearing masks — even though the employee wore a mask at all times, “during several encounters in a cell doorway or in the recreation room, IDPs did not wear masks.”
A spokesperson for the CDC told the Washington Examiner, “Wearing a mask is one of the most effective steps you can take to help stop the spread of COVID-19. A mask can protect other people from the virus-containing particles exhaled by someone who has COVID-19. As many as half of all people who have COVID-19 don’t show symptoms, so it’s critical to wear a mask because you could be carrying the virus and not know it.”
