美疾控中心重新定義疫情期間的“密切接觸者”

美國疾控中心日前修改了疫情防控指導意見中關於密切接觸者的定義，將時間較短但反覆接觸的情況也包括在內。新的定義明確，只要在24小時內與新冠病毒感染者接觸時間累計達15分鐘，就會被認定爲密切接觸者。

Federal health officials 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.

美國聯邦衛生官員本週三（10月21日）發佈了新指導意見，該意見更改了新冠病毒感染者的“密切接觸者”的定義，從而大大擴展了有感染新冠病毒風險的人羣範圍。

The change by the Centers for Disease Control and Prevention 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.

美國疾病控制與預防中心的這一改動可能對學校、辦公場所和其他人與人長時間接觸的聚集環境影響最大。該指導意見還強調了佩戴口罩以防止病毒傳播的重要性。

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.

美國疾控中心先前將“密切接觸者”定義爲在新冠肺炎確診患者6英尺（1.8米）範圍內持續停留至少15分鐘的人。根據疾控中心週三發佈的聲明，新版指導意見現在將密切接觸者定義爲24小時內在感染者6英尺範圍內停留時間總計達15分鐘以上的人。該指導意見是美國衛生部門追蹤密切接觸者的依據。

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, in the first news conference administration officials permitted in more than eight weeks. 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.

美國疾控中心負責傳染病的副主任傑伊·巴特勒本週三在疾控中心位於亞特蘭大的總部召開的新聞發佈會上稱，當前美國“不幸地呈現出一種令人不安的趨勢，全國近75%的地區新冠確診病例都在增加”。這是八週多以來政府官員許可召開的第一個新聞發佈會。巴特勒說，人們也許聽煩了這一建議，但是今年秋冬隨着美國人待在室內時間變長，病毒傳播風險變大，佩戴口罩比以往都更重要。

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. 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.

疾控中心的一名官員匿名透露，關於新冠病毒傳播的最新指導意見，疾控中心的科學家已經討論了好幾周。但是週三發佈的一份報告提出了讓人不安的新證據。疾控中心和佛蒙特州的衛生官員發現，一名20歲的監獄工作人員感染了新冠病毒，他在8個小時的值班過程中有過22次人員接觸，總時長超過17分鐘，和他接觸過的人後來新冠病毒檢測爲陽性。

"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.

疾控中心稱：“這份報告增進了人們對於新冠病毒接觸者風險的科學認識，再次凸顯了佩戴口罩對於防止病毒傳播的重要性。”

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.”

疾控中心表示，多達一半的新冠病毒感染者沒有症狀，“因此佩戴口罩很關鍵，因爲你可能攜帶病毒而不自知。儘管口罩對佩戴者的保護作用有限，但是每多一個人佩戴口罩，就對每個人多一份保護。如果更多人佩戴口罩，就有更多人受到保護。”

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

約翰斯·霍普金斯大學健康安全中心的流行病學家凱特琳·裏弗斯稱，指導意見的這一更新是重要改變。

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

裏弗斯說：“當你一整天都和其他人在一起時，碎片化的接觸時間很容易就能累積到15分鐘，比如飲水機邊的幾分鐘，電梯裏的幾分鐘，等等。我認爲這將導致更多人被認定爲密切接觸者。”

She added: “This change underscores the importance of vigilant social distancing — even multiple brief interactions can pose a risk.”

她補充道：“這一改變強調了提高社交隔離警惕的重要性，因爲即使是幾次短暫的互動也會構成風險。”