But an outbreak of flu that began as the war ended, turned out to be far more destructive.

但在該戰爭結束後發生的流感爆發，結果比戰爭本身還要嚴重。

It was known as the Spanish Influenza, and infected one in three humans on earth.

這個疾病被稱之為西班牙流感，當時世上三分之一的人都被感染了。

It was the worst pandemic in modern history and claimed the lives of between 50 and 100 million people.

現代史上最可怕的全球大流行疾病，奪走了五千萬至一億人口的性命。

Now, as a new strain of coronavirus spreads across the world, when does a disease become a pandemic and if it does, what happens next?

現在，新型冠狀病毒在全球肆虐，疾病何時會變成大流行，而之後又會如何呢？

Disease experts use the term "pandemic" when a new infection spreads to multiple countries and continents at the same time, affecting many people.

疾病學家以 pandemic (全球大流行) 一詞來描述在同時數國、州際間流傳，且感染許多人的疾病。

That's different from another term, epidemic, which describes an infection outbreak that's larger than usual, but stays confined to a single location or region.

這與另一個詞彙 epidemic (流行傳染病) 不同，此詞是指一個範圍性的爆發，但範圍維持在一個地點或地區。

So when does a disease officially become a pandemic?

那一個疾病究竟要什麼時候才會正式成為「全球大流行」？

The World Health Organization is the body that decides when an infectious disease formally becomes a pandemic, but that choice is not always black and white.

世衛組織是握有決定權的組織，但那個選擇並不是非黑即白。

The group's director-general says the WHO assesses whether to use the word "pandemic" by evaluating three things.

該組織的幹事長說，世衛組織用三個準則來評定是否使用 pandemic 一詞。

First is the geographical spread of the virus.

第一是病毒傳播的地點有多廣。

Second is the severity of the disease caused by the virus and lastly, the societal impact of the disease.

第二是該疾病的嚴重性，而最後則是該疾病帶來的社會影響。

A disease is more likely to become a pandemic if it is caused by a new strain of a virus, as is the case with Coronavirus Disease 2019 or COVID-19.

若為新型病毒則較容易成為全球大流行，如這次的新冠肺炎 (新冠病毒)。

The ease with which it infects people and spreads from person to person also play a role in the designation.

該病毒在人與人之間的傳染性也跟它是否能成為大流行有關係。

Past pandemic outbreaks have typically originated from animal viruses, before crossing over to humans.

過去的大流行病毒通常源自動物病毒，再間接傳染給人類。

These can spread rapidly around the world because people do not have the immunity needed to fight the new infection.

這種病毒可以快速地散播至全球，因為人們沒有足夠的免疫力來抵抗這種新型病毒。

COVID-19 was declared a pandemic in March 2020, the sixth pandemic declared in about a century.

新冠病毒在 2020 年 3 月被確認為全球大流行，是一百年來第六個大流行疾病。

The 1918 Spanish flu was easily the deadliest flu pandemic of the 20th century, killing tens of millions of people.

1918 年的西班牙流感是 20 世紀裡最致命的疾病，殺死了上千萬的人。

The Asian flu outbreak followed in 1957, killing roughly 1.1 million people around the world.

1957 年爆發的亞洲流感則在全球帶走了約 110 萬人。

Thankfully scientists were able to develop a vaccine quickly, effectively containing its spread.

當時幸虧科學家及早研發出疫苗，有效抑制病毒繼續傳播。

Another influenza outbreak, the Hong Kong flu, started to spread from China in 1968.

另一次則是香港流感，1968 年時從中國開始散播。

It was caused by a compound virus, which combined the Asian virus from ten years earlier with a form of bird flu.

這是一種複合式病毒，由十年前的亞洲病毒與一種禽流感組合而成的。

It killed around one million people—most of them older than 65.

這次流感殺死了約一百萬人，大多數人為超過 65 歲的長者。

HIV, which was first identified as the virus behind AIDS in 1983, was also considered a pandemic.

HIV 病毒，在 1983 年被確認為是愛滋病源頭的病圖，也曾被宣布為大流行。

The human immunodeficiency virus severely damages the cells in your immune system and weakens your ability to fight everyday infections and disease.

這種人類免疫缺乏病毒會破壞人類免疫系統的系統，導致人類無法抵抗各種疾病。

In the past 40 years, it's killed 35 million people worldwide, about half of the people who were infected by the virus.

過去 40 年來，HIV 病毒在全世界害死了 3,500 萬人，近乎所有感染者的一半。

Then in 2009, a new outbreak, initially called the swine flu, was named a pandemic.

2009 年時，又發生疾病爆發，一開始被稱為豬瘟，後來也被確定為大流行。

It infected nearly 61 million people, and experts estimate it killed up to 575,000 people in a single year.

該疾病感染了近乎 6,100 萬人，專家估計一年之中最多有 57.5 萬人死於該疾病。

The WHO declared the pandemic over in August 2010, but the virus has continued to circulate as a seasonal flu ever since.

世衛組織在 2010 年 8 月宣布豬瘟為大流行，該病毒自那時起成為季節性流感不斷侵擾人類。

In recent years, the WHO has changed how it decides whether an outbreak constitutes a pandemic, following criticism that the threat of the 2009 swine flu had been exaggerated.

近年來，世衛組織對於決定一個疾病是否為大流行的流程有了變化，因有批評指出 2009 年時豬瘟事件被過度放大。

Many governments stockpiled vaccines which ultimately went unused, while pharmaceutical companies profiteered from the ensuing panic.

當時多國政府囤積疫苗，最後卻浪費了，而醫療公司因此大量獲利。

The disease turned out to be milder than was originally thought.

結果該疾病比預想中更輕微。

Since then, the WHO has released a guide to manage flu pandemics at a national and international level.

自此，世衛組織發布了一份指南，以國家與國際等級來控管大流行流感。

According to its pandemic preparedness plan, national governments are required to follow specific protocols – if a pandemic is declared – to prevent or reduce the spread of a virus.

根據該大流行準備書，國家政府在宣布大流行後，需遵守一些準則來預防或減緩病毒的散播。

For instance, authorities at a regional and local level must fully mobilize health systems, hospitals and medical workers.

舉例來說，地區或地方政府得完全動員醫療系統、醫院及醫療人員。

In addition, healthcare providers must plan for a surge in patients, and offer protective equipment to their workforce.

此外，醫療機構得為可能激增的病人數做好準備，並提供醫療人員保護裝備。

Governments must also limit social interaction, initiate quarantine measures and enforce isolation procedures.

政府機構也應限制人們的社交互動，啟動隔離機制與程序。

Upgrading a disease to a pandemic outbreak also has psychological implications for how we think about a disaster.

將一種疾病升級為全球大流行，也會使我們對該疾病的想法產生一些心理暗示。

According to the WHO "using the word pandemic carelessly has no tangible benefit, but it does have significant risk in terms of amplifying unnecessary and unjustified fear and stigma."

據世衛組織所說：「魯莽使用大流行一詞，不會有什麼益處，只會放大無謂的恐懼及歧視。」

Six months before the latest coronavirus outbreak, a WHO report noted that "many countries still lack a national pandemic influenza preparedness plan."

在新冠病毒爆發前半年，一份世衛組織的報告指出「許多國家仍然缺乏國家流感大流行準備計畫」。

So what are the economic costs of a pandemic?

那全球大流行疾病會對經濟帶來何種影響？

A previous coronavirus strain called SARS, which was detected in 2002, wasn't widespread enough to become a pandemic.

上一種侵襲人類的冠狀病毒為 SARS，在 2002 年時被發現，但並沒有成為大流行。

While it only infected more than 8,000 people, it still cost the global economy more than 50 billion USD in 2003.

SARS 僅僅感染了 8,000 餘人，但它還是在 2003 年造成了全球超過 500 億美元的經濟損失。

You see, advances in medicine, communication and technology have brought mortality rates down.

醫療、通訊與科技的進步讓死亡率下降。

But greater trade flows and cheaper air travel have seen the world economy become ever more interconnected and that causes the costs of a pandemic to rise.

但貿易發展與越發便宜的航空旅行，讓全球緊緊連結，也使得大流行疾病發生的代價更高。

A report now estimates that a pandemic will cost 570 billion USD a year.

一份報告估計，大流行疾病將造成全球一年 5,700 億美元的損失。

That represents 0.7 percent of the world's total income.

這代表全世界 0.7% 的收入。

A pandemic can overwhelm global health systems.

大流行疾病也會使全球的醫療系統超出負擔。

It can also force infected individuals to avoid the office or work less productively.

也會使受感染的個體離開工作崗位，或降低生產力。

The fear of infection spread forces people to stay apart.

害怕被感染的恐懼使得人們對彼此保持距離。

And that can be even more debilitating… shutting down schools, businesses and public services.

還有可能更慘，學校、企業甚至公共設施都可能關閉。

Insurance companies must also watch developments closely.

保險公司也得密切注意疫情發展。

A pandemic can mean more travel claims, more hospital claims and choke up global supply chains.

大流行疫情會帶來更多旅行、醫療糾紛，使得全球供應鏈受到阻礙。

The impact on corporate earnings can then cascade into financial markets all around the world.

一連串對企業的影響，最終會傷害到世界經濟市場的發展。

Hi, guys. Thanks for watching our video. If you want to see more of our content, you can check out these videos. And remember, don't forget to subscribe.

嗨，謝謝收看，如果想看更多可以看這些影片，另外，別忘了訂閱！