Why is it so dangerous to step on a rusty nail? - Louise Thwaites

翻译人员: Liwen Huang 校对人员: Sue Lu

In the 5th century, Greek physician Hippocrates,

在 5 世纪，希腊医生希波克拉底，

creator of the Hippocratic Oath, was sailing with a very ill shipmaster.

即希波克拉底誓言的创立者， 正与一位病重的船长一起航行。

The captain was suffering a nasty infection

船长遭受严重感染，

that caused his jaws to press together, his teeth to lock up,

导致他下颌紧闭，牙关咬合，

and the muscles in his neck and spine to spasm.

颈部和脊柱肌肉痉挛。

Hippocrates dutifully recorded these symptoms,

希波克拉底尽职尽责地记录了这些症状，

but he was unable to treat the mysterious disease.

但他无法治疗这种神秘的疾病。

And six days later, the shipmaster succumbed to his illness.

六天后，船长死于疾病。

Today, we know this account to be one of the first recorded cases of tetanus,

这是最早记录在案的一例破伤风，

and thankfully, modern physicians are much more prepared

值得庆幸的是，现代医生准备更充分，

to handle this peculiar infection.

能够应对这种特殊感染。

Unlike other common bacterial infections like tuberculosis and strep throat,

与肺结核和脓毒性咽喉炎等 常见细菌感染不同，

tetanus doesn’t pass from person to person.

破伤风不在人与人之间传播。

Instead, the offending bacterium, known as Clostridium tetani,

相反，致病菌，即破伤风杆菌，

infects the body through cuts and abrasions.

通过割伤和擦伤感染人体。

These infection sites are why tetanus is so strongly associated

这些感染部位表明， 与破伤风密切相关的是

with rusty nails and scrap metal, which can cause such wounds,

锈钉和废金属， 它们容易造成这类伤口，

but the condition's connection to rust is actually much less direct.

但破伤风与锈并无多少直接关系。

Clostridium tetani bacteria are often found in soil, manure, and dead leaves,

破伤风杆菌通常存在 于土壤、粪肥和枯叶中，

where they can survive for years in the form of spores,

能以孢子的形式存活多年，

even amidst extreme heat and dryness.

哪怕是在极端高温和干燥的环境。

These piles of organic material can sit undisturbed for long periods,

这些成堆的有机物质可能长期不被触及，

potentially concealing old metal, which rusts over time.

掩盖着随时间推移而生锈的旧金属。

So, if someone does blunder into this environment and cuts themselves,

因此，如果有人误入 这种环境还划伤了自己，

it would likely increase their odds of infection.

很可能会增加感染的几率。

Especially since rusty metal can create jagged wounds

特别是生锈金属会造成锯齿状伤口，

with lots of deoxygenated dead tissue for them to latch on to.

伤口含大量脱氧坏死组织， 可供孢子依附。

Once in the body, the spores begin to germinate.

孢子一进入体内就开始生长，

This process releases several toxins, including deadly tetanus toxin.

并在此过程中释放多种毒素， 包括致命的破伤风毒素。

Nerve endings soak up this toxin,

神经末梢吸收这种毒素，

drawing it into the brain and spinal cord where it wreaks havoc on interneurons.

将其吸入大脑和脊髓， 严重破坏中间神经元。

Typically, these work alongside motor neurons to regulate our muscle actions,

通常，中间神经元与运动神经元 一起控制肌肉运动，

from endeavors as complex as kicking a ball to those as simple as breathing.

从踢球一类的复杂运动 到呼吸一类的简单运动。

But by blocking neurotransmitters released by interneurons,

但是，通过阻断中间神经元 释放的神经递质，

tetanus toxin causes uncontrollable muscle contractions and spasms.

破伤风毒素会导致 失控的肌肉收缩和痉挛。

Typically within 7 to 10 days of infection,

通常在感染后 7 到 10 天内，

patients begin experiencing general aches, trouble swallowing, and lockjaw.

患者开始出现全身疼痛、 吞咽困难和下颌紧闭。

The head and neck tend to show symptoms first.

头部和颈部往往最先出现症状。

But as the toxin spreads, stronger muscle groups become more rigid,

但是随着毒素的扩散， 更强壮的肌肉群变得更加僵硬，

leading to a frightening arching of the back.

导致可怕的背部弓形。

Left untreated, these spasms become more extreme,

如果不加以治疗， 这些痉挛会变得更为严重，

eventually seizing the muscles in the windpipe and chest,

最终侵袭气管和胸部肌肉，

leading patients to suffocate within 72 hours of symptoms appearing.

导致患者在症状出现后 72 小时内窒息。

Without treatment, tetanus has an extremely low rate of survival.

如果不进行治疗，破伤风的存活率极低。

But fortunately, medical professionals have developed a robust plan

但幸运的是，医疗专业人员 已经制定了一项强有力的计划

to handle a tetanus diagnosis.

来处理破伤风的诊断。

First, doctors clean the infected wound and administer antibiotics,

首先，医生清洗感染的伤口 并使用抗生素，

killing the bacteria and preventing further toxin production.

以杀死细菌并防止更多毒素的产生。

Then, they inject antitoxin to neutralize any tetanus toxin

然后，他们注射抗毒素来中和体内

still in the body that has yet to enter the central nervous system.

尚未进入中枢神经系统的破伤风毒素。

Finally, patients begin a several week period of supportive care,

最后，患者开始为期几周的支持性护理，

which can include muscle relaxants to stop spasms

可能包括用肌肉松弛剂停止痉挛

and ventilators to prevent suffocation.

以及用呼吸机防止窒息。

In the days of Hippocrates, the only course of treatment was to wait and hope.

在希波克拉底时代， 唯一的治疗方法是等待和希望。

But now we know the best time to tackle Clostridium tetani

但是现在我们知道 应对破伤风杆菌的最佳时机

is before an infection even takes place.

是在感染发生之前。

Tetanus vaccines— originally developed in the early 1920s—

破伤风疫苗—— 最初研发于 1920 年代初——

are crucial to preventing tetanus and stopping its spread.

对预防破伤风和阻止其传播至关重要。

Experts recommend a series of shots and boosters beginning at two months old

专家建议从两个月开始 接种一系列的疫苗和加强疫苗，

and ending around age 12.

到 12 岁左右结束。

Yet over 20,000 infants still die of tetanus every year,

然而，每年仍有 2 万多名婴儿死于破伤风，

mostly in low and middle income countries where vaccine access is limited,

主要在疫苗获取有限的中低收入国家，

including South Asia and sub-Saharan Africa.

包括南亚和撒哈拉以南非洲地区。

And newborn babies are especially at risk if their mothers are unvaccinated,

而且，如果母亲未接种疫苗， 新生儿面临的风险尤其大，

as Clostridium tetani can infect a newborn's umbilical stump.

因为破伤杆菌会感染新生儿的脐带残端。

Though vaccinating mothers during pregnancy can help with this problem.

不过母亲在怀孕期间接种疫苗 有助于解决这个问题，

The fact is tetanus remains a significant threat to human health.

事实是，破伤风仍然严重威胁人类健康。

So people should get vaccinated

因此，人们应该接种疫苗，

and take measures to prevent infection after cutting themselves—

并采取措施防止划伤后感染，

whether it’s on a rusty nail or a 2,400-year-old ship anchor.

无论是被生锈的钉子, 还是被有 2400 年历史的船锚划伤。