What makes tuberculosis (TB) the world's most infectious killer? - Melvin Sanicas

譯者: Lilian Chiu 審譯者: Helen Chang

In 2008, archeologists uncovered two 9,000-year old skeletons.

2008 年，

考古學家發現了 兩具九千年前的骸骨。

There’s no definitive way of knowing what killed these ancient people,

沒有辦法完全肯定 這些古人是怎麼死的，

but we do know their bones were infected by an all too familiar bacterium.

但我們確實知道，他們的骨頭曾 受到我們非常熟悉的細菌所感染。

The ancient Greeks knew its consumptive effects as phthisis;

古希臘把它對於 肺部的影響稱為肺結核；

the Incans called it chaky oncay; and the English called it tuberculosis.

印加人稱之為「chaky oncay」，

英文把它叫做結核病。

Today, tuberculosis, or TB,

現今，結核病（簡稱 TB）

is still one of the world’s biggest infectious killers,

仍然是世界上最強大的 感染性殺手之一，

causing more deaths than malaria or even HIV and AIDS.

造成的死亡數目超過 瘧疾或甚至愛滋病。

But what exactly is this disease, and how has this pathogen persisted for so long?

但這疾病到底是什麼？

它的病原體如何能存留這麼久？

Typically, TB bacteria called mycobacterium tuberculosis, are airborne.

結核病細菌，即結核桿菌， 通常透過空氣傳染。

They travel into our airways and infect our lungs.

它們會進入我們的氣道， 感染我們的肺部。

Here, immune cells called macrophages rush to the infection site,

叫做巨噬細胞的免疫細胞 會趕到被感染處，

attempting to absorb and break down the bacterial invaders.

試圖吸收和擊潰入侵的細菌。

In many cases, this response is enough to remove the bacteria.

在許多情況下 這反應足以除去細菌。

But in individuals with other medical conditions–

但若病人有其他疾病或醫療狀況——

ranging from malnutrition and HIV to diabetes and pregnancy

從營養失調、愛滋病 到糖尿病及懷孕——

–the immune response may not be strong enough to destroy the intruder.

免疫反應可能不夠強， 無法摧毀入侵者。

If so, mycobacterium tuberculosis will reproduce inside those macrophages,

如果這樣的話，結核桿菌 會在那些巨噬细胞中繁殖，

and form colonies in the surrounding lung tissue.

在周圍的肺部組織中形成菌落。

As they infect more cells,

當細菌感染更多細胞時，

the bacteria employ cell-degrading enzymes that destroy the infected tissue,

細菌會使用能分解細胞的酵素 來摧毀受到感染的組織，

triggering chest pain, and causing patients to cough up blood.

觸發胸痛，造成病人咳出血。

The damage to the lungs leads to oxygen deprivation.

肺部受到的損傷會導致氧氣喪失。

This begins a flood of hormonal changes–

接著就會開始發生 許多荷爾蒙改變——

including a decrease in appetite and iron production.

包括食慾下降和鐵的產生下降。

From here, microbes can spread to the skeletal system,

微生物自此散播到骨骼系統，

causing back pain and difficulty moving;

造成背痛以及行動困難；

to the kidneys and intestines, causing abdominal pain;

散播到腎臟和腸子，會造成腹痛；

and to the brain, causing headaches and even impaired consciousness.

散播到大腦，會造成頭痛， 甚至意識的損害。

These symptoms produce the classic image of TB:

這些症狀形成了典型的結核病形象：

weight loss, a hacking, bloody cough, and ashen skin.

體重下降、帶血的乾咳， 以及皮膚灰白。

This ghostly appearance earned TB the title of the ‘White Plague’

結核病造成這種像鬼一樣的外表， 讓它在維多莉亞時代的英國

in Victorian-era England.

得到了「白色瘟疫」之名。

During this period, tuberculosis was considered a ‘romantic disease,'

當時結核病被認為是種 「浪漫的疾病」，

because it tended to affect poverty- stricken artists and poets–

因為通常是貧窮、受挫的 藝術家和詩人會得到這種病—–

those with weaker immune systems.

他們的免疫系統比較弱。

TB’s outward symptoms even helped fuel the popular myth of vampirism.

結核病的外在症狀甚至 讓吸血鬼迷信變得更流行。

In spite of– or perhaps because of these less than scientific concerns,

儘管——或者是因為 這些不太科學的擔憂，

this period also marked the first strides toward curing TB.

此一時期標誌著 治療結核病的第一步。

In 1882, the German physician Robert Koch

1882 年，德國醫生羅伯柯霍

identified the disease’s bacterial origins.

找出了這種疾病的細菌來源。

13 years later, physicist Wilhelm Roentgen  discovered the X-ray,

十三年後，物理學家 威廉倫琴發現了 X 光，

enabling physicians to diagnose and track its progression through the body.

讓醫生可以診斷和追蹤 結核病在身體中的發展。

These techniques allowed researchers to develop reliable and effective vaccines–

這些技術讓研究者得以開發出 可靠、有效的疫苗——

first for smallpox, and again in 1921,

先是治療天花，接著，1921 年，

when scientists developed the BCG vaccine to battle TB.

科學家開發出卡介苗 來對抗結核病。

These developments laid the groundwork for the modern field of antibiotics–

這些發展為現代的抗生素領域奠基——

currently home to our most effective TB treatments.

我們目前最有效的結核病 治療方式就是從這裡來的。

But, antibiotics fail to address a major diagnostic complication:

但，抗生素無法處理 主要的診斷併發症：

about 90% of people infected with TB don’t show any symptoms.

九成感染結核病的人 不呈現任何症狀。

In these latent infections, the TB bacterium may be dormant,

在這些潛伏性感染的案例中， 結核細菌可能是在休止狀態，

only activating when someone’s immune system is too weak to mount a defense.

只在病人的免疫系統 弱到無法防禦時，才開始活動。

This makes TB much harder to diagnose.

因此使得結核病更難診斷。

And even when properly identified,

就算正確辨識出結核病，

traditional treatments can take up to 9 months,

傳統的治療可能要花上九個月，

requiring multiple drugs and a high potential for side effects.

需要用多種藥物， 很有可能會有副作用。

This discourages people from finishing the full course,

這會讓病人完成 完整療程的意願下降，

and partial treatment enables bacteria to develop resistance to these drugs.

只做部分療程，

反而讓細菌對這些藥物 發展出抗藥性。

Today, the disease is still prevalent in 30 countries,

結核病現今仍在三十個國家流行，

most of which face other health crises

大多數是有其他健康危機的國家，

that exacerbate TB and trigger latent cases.

讓結核病惡化，觸發潛伏的案例。

Worse still, accessing treatment can be difficult in many of these countries,

還有更糟的，在這些國家中， 治療通常取得不易，

and the stigma towards TB can discourage people from getting the help they need.

而結核病的汙名，會讓病人不願 曝光去取得他們需要的協助。

Health experts agree we need to develop better diagnostics,

健康專家同意，我們需要 開發出更好的診斷方式、

faster acting antibiotics, and more effective vaccines.

反應更快的抗生素， 以及更有效的疫苗。

Researchers have already developed a urine test that yields results in 12 hours,

研究者已開發出了一種尿液檢測， 能在十二小時內產出結果，

as well as a new oral treatment that could cut treatment time by 75%.

以及一種新的口服藥物治療， 能將治療時間減為四分之一。

Hopefully, with advancements like these,

希望，有了像這樣的進步，

we’ll finally be able to make TB exclusively a thing of the past.

我們最終能讓結核病成為過去式。