Take a look through the news stories and you'll see photos of concerned citizens with their faces covered.

大略看一下新聞版面，可以看到臉被遮掩起來，憂心忡忡的市民們。

But is covering your mouth enough to prevent this life-threatening illness?

但遮住嘴巴足夠讓你免於這會威脅到性命的疾病嗎？

And if not, what's really the best way to stay healthy?

如果答案是否定的，什麼才是保持健康的最佳方法呢？

We spoke with an expert to better understand this outbreak.

我們諮詢了一位專家以更加暸解這個疾病的爆發。

So coronaviruses are a large family of viruses that are responsible for about 25 % of cases of the common cold.

冠狀病毒是一族各種不同病毒的總稱，他們引起了約百分之 25 的常見感冒。

Before this latest outbreak, there were six coronaviruses that were known to infect humans.

在這個最新的疫情爆發之前，有六種冠狀病毒為我們所熟知會感染人類。

And four of them were just kind of common cold viruses that occasionally could cause pneumonia or severe disease.

而其中四種是會偶爾引起肺炎的普通感冒病毒。

Coronavirus is an umbrella term that refers to a family of upper-respiratory diseases, including the common cold, MERS and SARS.

冠狀病毒是指一族會引起上呼吸道疾病的病毒的總稱，包括引起一般感冒、MERS 和 SARS。

The virus can present in several ways.

這種病毒有多種表徵方式。

Sometimes as a mild illness and sometimes as a life-threatening disease.

有時候是輕微的感冒，有時是威脅生命的疾病。

The current strain in China is highly contagious, hundreds of people have been infected, and several have died.

目前在大陸流行的病毒品系非常具傳染力，數以百計的人被感染，還有數位病患因病去世。

On January 21, it was confirmed that this strain of coronavirus has made its way to the U.S.

在 1 月 21 日，確認了這種引起新冠肺炎的病毒已經擴散至美國。

Soft surgical masks, like the one shown here, are designed to prevent the wearer from spreading their germs to others.

軟的外科口罩，如圖所示，它的設計是為了防止將細菌傳染給別人。

But they won't prevent inhalation of airborne germs.

但它們沒辦法防止戴口罩者吸入透過空氣傳播的細菌。

Their loose sides reduce their effectiveness as a barrier against disease.

它們不緊密的側邊降低了口罩作為阻擋空氣傳播細菌屏障的有效性。

To block out the greatest number of airborne germs, you'd need an N95 respirator mask.

要阻擋絕大多數的空氣傳播細菌，你需要一個 N95 口罩。

This mask is what a surgeon would wear around a patient with a highly infectious disease, like tuberculosis.

這是當外科醫生在附近有一位病患患有高度傳染力疾病時會戴的口罩，如肺結核。

These masks aren't a foolproof solution for the public either.

這些口罩也不是避免生病萬無一失的方法。

Surgeons get their masks fitted and generally only wear them for a short period of time.

外科醫師的口罩非常貼合臉部，基本上只戴它們一小段時間。

Just buying a mask from the drugstore wouldn't give you the same snug fit around the mouth that keeps those germs from getting in.

在藥妝店購買的口罩不會在口部附近如此服貼以避免細菌進入。

Furthermore, respirator masks actually filter air, which makes them a great barrier against disease.

此外，N95 口罩會過濾空氣，使它們成為一個更強大的防疫屏障。

But according to Dr. Amesh Adalja, they restrict oxygen flow too much to be worn all day.

但根據 Amesh Adalja 博士，這類型的口罩會限制氧氣進入口罩內，因此很難全天戴著。

A study conducted by the University of New South Wales found that when worn correctly, these masks have an 80% efficacy rate of protecting the wearer against a proven viral infection.

一份新南威爾斯大學的研究顯示，正確配戴口罩可以保障 80% 的人避免受到病毒感染。

This study focused on the spread of influenza, but Dr. Adalja says that the two diseases spread in comparable ways.

這份研究主要在討論流感的傳播，但 Adalia 博士指出兩種疾病是以類似的方式傳染。

Coronaviruses spread through the respiratory route, so that's through coughs and sneezes and little droplets to come out of your mouth.

冠狀病毒是透過呼吸道路徑侵入病患，所以是透過從你嘴巴噴出的口沫小滴、咳嗽或噴嚏。

And that's pretty much very similar to the influenza.

而這個與流感非常類似。

They do spread very readily, and that's the concern when you have one that can cause severe illness.

他們擴散得非常迅速，他們可以造成很嚴重的病徵，所以這是令人憂心的地方。

Unfortunately there's a catch.

但不幸的是，這之中帶有玄機。

The same study found that mask-usage compliance, or the portion of people using the masks effectively was only 50%.

在同一份研究顯示，民眾正確使用口罩或有效配戴口罩的比例只有 50 %。

With the noncompliant users incorporated, there was no difference in infection rate between the mask wearers and the control group.

如果將沒有正確配戴口罩的使用者納入考量，戴口罩的對照組與不戴口罩的控制組感染率沒有差別。

So what's the best way to keep yourself safe?

所以什麼才是最好保持安全的方法呢？

Dr. Adalja's advice is simple.

Adalja 博士的建議很簡單。

So the best thing you can really do is to practice good hygiene, wash your hands, stay away from sick people if you can.

你能做到最好的事情就是保持良好衛生習慣，勤洗手，如果可以的話遠離病患。

If you're in those parts of China where cases have occurred, you want to stay away from the live animal markets which may have been part of the origin of this new virus.

如果你在中國疫區，遠離可能是新型病毒源頭的生鮮市場。

But there isn't anything specific you can do other than a lot of common sense and good hygiene.

除了保持大量正確的防疫知識與良好的衛生習慣，你沒有其他特別可以做的事來避免感染。

If you do choose to wear a mask, try to follow the rules:

如果你選擇戴口罩，試著遵循以下條件：

Don't remove the mask frequently, touch your face under the mask or reuse it.

不要經常拿掉口罩、在口罩下摸臉或重複使用口罩。

Doing so will greatly diminish its benefits.

如果做了這些會大幅減輕口罩的功效。

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想看更多類似這種主題的影片，按下訂閱以得到更多通知。

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不要忘記按小鈴鐺。