CDC expands definition of ‘close contact’ of an individual with COVID-19
The Centers for Disease Control and Prevention this week issued new guidance on Wednesday that greatly expands the pool of people considered at risk of contracting the novel coronavirus by changing the definition of who is a “close contact” of an infected individual.
The change by the CDC is likely to have its biggest impact in schools, workplaces and other group settings where people are in contact with others for long periods of time. It also underscores the importance of mask-wearing to prevent spread of the virus, even as President Trump and his top coronavirus adviser continue to raise doubts about such guidance.
The CDC had previously defined a “close contact” as someone who spent at least 15 consecutive minutes within six feet of a confirmed coronavirus case. The updated guidance, which health departments rely on to conduct contact tracing, now defines a close contact as someone who was within six feet of an infected individual for a total of 15 minutes or more over a 24-hour period, according to a CDC statement Wednesday.
The update comes as the United States is “unfortunately seeing a distressing trend, with cases increasing in nearly 75 percent of the country,” Jay Butler, the CDC’s deputy director for infectious diseases, said Wednesday at CDC headquarters in Atlanta. People may be tired of the advice, Butler said, but mask-wearing is more important than ever this fall and winter as Americans head indoors, where transmission risks are greater.
The guidance about transmission of the coronavirus, which causes covid-19, had been discussed by CDC scientists for several weeks, according to a CDC official who spoke on the condition of anonymity to share policy discussions. Then came unsettling new evidence in a report published Wednesday. CDC and Vermont health officials discovered the virus was contracted by a 20-year-old prison employee who in an eight-hour shift had 22 interactions — for a total of over 17 minutes — with individuals who later tested positive for the virus.
“Available data suggests that at least one of the asymptomatic [infectious detainees] transmitted” the virus during these brief encounters, the report said.
“This article adds to the scientific knowledge of the risk to contacts of those with covid-19 and highlights again the importance of wearing face masks to prevent transmission,” the CDC said.
As many as half of all people who have the virus don’t show symptoms, “so it’s critical to wear a mask because you could be carrying the virus and not know it,” the CDC said. “While a mask provides some limited protection to the wearer, each additional person who wears a mask increases the individual protection for everyone. When more people wear masks, more people are protected.”