发布者: 千缘 | 发布时间: 2021-1-24 02:48| 查看数: 85| 评论数: 0|

Federal health officials issued new guidance onWednesday that greatly expands the pool of peopleconsidered at risk of contracting the novelcoronavirus by changing the definition of who is a"close contact" of an infected individual.


The change by the Centers for Disease Control andPrevention is likely to have its biggest impact inschools, workplaces and other group settings wherepeople are in contact with others for long periods of time. It also underscores the importance ofmask-wearing to preventspread of the virus.


The CDC had previouslydefined a "close contact" as someone who spent at least 15consecutive 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 assomeone who was within six feet of an infected individual for a total of 15 minutes or moreover a 24-hour period, according to a CDC statement Wednesday.


The update comes as the United States is "unfortunately seeing a distressingtrend, withcases increasing in nearly 75 percent of the country," Jay Butler, the CDC's deputydirector forinfectious diseases, said Wednesday at CDC headquarters in Atlanta, in the first newsconferenceadministration officials permitted in more than eight weeks. People may be tiredof the advice, Butler said, but mask-wearing is more important than ever this fall and winter asAmericans head indoors, where transmission risks are greater.



The guidance about transmission of the coronavirus, which causes covid-19, had beendiscussed by CDC scientists for several weeks, according to a CDC official who spoke on thecondition of anonymity. Then came unsettling new evidence in a report publishedWednesday. 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 over17 minutes — with individuals who later tested positive for the virus.


"This article adds to the scientific knowledge of the risk to contacts of those with covid-19 andhighlights 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 weara mask because you could be carrying the virus and not know it," the CDC said. "While a maskprovides some limitedprotection to the wearer, each additional person who wears a maskincreases the individual protection for everyone. When more people wear masks, more peopleare protected."


Caitlin Rivers, an epidemiologist at the Johns Hopkins Center for Health Security, called theupdated guidance an important change.


"It's easy to accumulate 15 minutes in small increments when you spend all day together — afew minutes at the water cooler, a few minutes in the elevator, and so on," Rivers said. "Iexpect this will result in many more people being identified as close contacts."


She added: "This change underscores the importance of vigilantsocial distancing — evenmultiple brief interactions can pose a risk."



快速回复 返回顶部 返回列表