Why is meningitis so dangerous? - Melvin Sanicas

翻译人员: Yichen Huang 校对人员: Yingyu Liu

In 1987, tens of thousands of people

在1987年，数以万计的人

gathered in Saudi Arabia for the annual Hajj pilgrimage.

聚集在沙特阿拉伯， 参加一年一度的麦加朝圣。

But what started out as a celebration led to a health crisis:

但本是一场宗教仪式的朝圣， 却导致了一场健康危机。

just a few days after the pilgrimage,

仅在朝圣后的几天，

more than 2,000 cases of meningitis broke out

就有超过2000起脑膜炎病例爆发，

spreading across Saudi Arabia and the rest of the world.

并扩散到整个沙特阿拉伯 和世界其他地区。

The outbreak was so fierce

这场爆发势头强劲，

that it was believed to have sparked a wave of deadly meningitis epidemics

以至于引发了一轮致死性脑膜炎的大流行，

that ultimately infected tens of thousands of people worldwide.

最终使得全球数以万计的人被感染。

Meningitis is the inflammation of the meninges,

脑膜炎是脑膜的炎症，

three tissue layers responsible for protecting the brain and spinal cord.

脑膜是保护脑和脊髓的三层组织。

What makes meningitis so dangerous compared to other diseases

脑膜炎比起其他疾病十分致命，

is the sheer speed with which it invades a person’s body.

是因为它以极快的速度入侵人体。

In the worst cases, it causes death within a day.

在极端的案例中， 脑膜炎可在一天内致死。

Fortunately, that’s rare for patients who receive early medical treatment.

幸运的是，这种情况在 及时接受治疗的患者中很少见。

The disease primarily comes in three forms:

脑膜炎主要有三种形式：

fungal, viral, and bacterial-- the last being the most deadly by far,

真菌，病毒和细菌。

细菌性脑膜炎是三者中最危险的， 我们会解释此类脑膜炎的机理。

and what we’ll focus on.

People usually contract bacterial meningitis by breathing in

当脑膜炎患者咳嗽或打喷嚏时，

tiny particles of mucus and saliva that spray into the air

空气中的黏液和唾液微粒可能会被吸入

when an infected person sneezes or coughs.

以导致细菌性脑膜炎的传播。

It can also be transmitted through kissing,

此类脑膜炎也可以通过接吻、

or sharing cigarettes, toothbrushes or utensils.

共享香烟、牙刷或餐具传播。

Some people can be infected and carry the disease

有些患者可能不会 显现出明显的症状，

without showing symptoms or getting sick,

which helps the disease spread quickly to others.

使得脑膜炎在人群中快速传播。

Once the bacteria enter the nose, mouth, and throat,

一旦细菌进入鼻腔、口腔和咽喉，

they cross the surrounding membranes and enter the bloodstream.

就会跨越周围的黏膜并进入血液循环。

From there, bacteria have rapid access to the body’s tissues

在血液中，细菌可以快速侵入人体组织。

--including a membrane called the blood-brain barrier.

这些组织包括了血脑屏障：

This is made of a tight mesh of cells which separate blood vessels from the brain,

一种隔开血管和脑的， 由细胞紧密排列组成的膜。

and block everything except for a specific set of particles,

血脑屏障只允许特定的微粒通过，

including water molecules and some gases.

包括水分子和一些气体。

But in ways that scientists are still trying to understand,

但让科学家困惑的是，

meningitis bacteria can trick the barrier into letting them through.

导致脑膜炎的细菌 会“欺骗”血脑屏障来允许它通过。

Inside the brain, the bacteria swiftly infect the meninges.

在脑中，细菌会快速感染脑膜，

This triggers inflammation as the body’s immune response kicks into overdrive,

使得人体发生激烈的 免疫反应，引起炎症，

bringing on fever and intense headaches.

并导致发热和强烈的头痛。

As swelling in the meninges worsens, the neck begins to stiffen.

脑膜的肿胀加剧会使得患者的颈部僵硬，

Swelling in the brain disrupts its normal function--

并阻碍脑的正常功能，

causing symptoms like hearing loss and extreme light sensitivity.

导致失聪或畏光等症状。

As pressure increases in the cranium, it may also make the person confused--

颅内压力的增加会导致神志模糊，

one of the hallmarks of the disease.

这是脑膜炎的典型症状之一。

A few hours in, the rapidly multiplying bacteria start to release toxins,

在数个小时中，快速繁殖的 细菌会开始释放毒素，

leading to septicemia, also known as blood poisoning.

导致败血病。

This breaks down blood vessels,

败血病会破坏血管，

letting blood seep out and form what starts out looking like a rash,

从血管中渗出的血液 会形成形如皮疹的淤血

and evolves into big discoloured blots beneath the skin.

并不断扩大。

At the same time, these toxins burn through oxygen in the blood,

同时，细菌中的毒素 会大量消耗血液中的氧气，

reducing the amount that gets to major organs like the lungs and kidneys.

减少肺和肾等重要器官的供氧。

That increases the chance of organ shut down

这会增加器官衰竭的几率，

--and alongside spreading septicemia, threatens death.

并使败血病扩散，有致死风险。

That all sounds scary, but doctors are so good at treating meningitis

这听起来很吓人， 但现代医学可以有效治疗脑膜炎，

that a visit to the hospital can drastically reduce an adult’s risk of dying from it.

及时治疗可以显著减少脑膜炎的致死几率。 （接受治疗的脑膜炎病患中死亡率低于2%）

The longer it’s left untreated, though,

然而，若是不及时接受治疗，

the more likely it will lead to lasting damage.

脑膜炎就可能造成长期的损害。

If declining oxygen levels cause cell death in extreme parts of the body

若是细胞缺氧导致肢体末端的细胞死亡，

--like fingers, toes, arms and legs-- the risk of amputation goes up.

如手指、脚趾和上下肢， 截肢风险就会上升。

And if bacterial toxins accumulate in the brain and trigger cell death,

若细菌毒素在脑中积累并引发细胞死亡，

meningitis could also cause long-term brain damage and memory loss.

脑膜炎就会造成长期的脑损伤和失忆。

So fast treatment, or better yet, prevention, is critical.

所以及时的治疗或是预防十分重要。

That's why most countries have vaccines that defend against the disease

因此绝大多数国家 都有针对细菌性脑膜炎的育苗储备。

in its deadliest forms.

Those are usually given to the people who are most at risk--like young children,

此类疫苗通常被分配给易感染脑膜炎的群体，

如幼儿，免疫系统虚弱者 和经常处于大量人群中的人。

people with weak immune systems, or people who gather in large groups

where an outbreak of meningitis could potentially happen.

在这些群体中，脑膜炎更容易爆发。

In addition to those gatherings,

除了人群聚集处，

meningitis is most common in a region called the meningitis belt

脑膜炎最多发于被称作“脑膜炎带”的地区，

that stretches across Africa, though cases do happen all over the world.

这个地区横跨非洲。 当然，全球的其他地区也出现过脑膜炎的病例。

If you’re concerned that you or someone you know may have meningitis,

若你担心你或你认识的人患有脑膜炎，

get to the doctor as soon as possible;

请尽快就医！

quick action could save your life.

及时的治疗可能拯救生命。