This month, a pair of viruses seized the headlines. First came a hantavirus outbreak aboard a cruise ship, which caused as many as 13 infections, three of which were fatal. Then an Ebola outbreak flared in Africa, so far leading to more than 900 infections and 220 deaths.

本月，两种病毒占据了新闻头条。先是一艘邮轮上暴发了汉坦病毒疫情，导致多达13人感染，其中三人死亡。紧接着，非洲爆发了埃博拉疫情，截至目前已导致900多人感染，220人死亡。

In both cases, the news has been not only frightening but also confusing, even to scientists. The hantaviruses didn’t seem to be acting like hantaviruses, and the Ebola viruses weren’t behaving like Ebola viruses.

在两起事件中，相关新闻不仅令人惊恐，而且令人困惑，甚至对科学家来说也是如此。此次汉坦病毒的表现似乎不再像汉坦病毒，而埃博拉病毒的表现也不再像埃博拉病毒。

Hantaviruses are carried by rodents and other animals, and typically infect people who inhale dried animal urine and saliva. But aboard the cruise ship M.V. Hondius, hantaviruses were moving from person to person.

汉坦病毒由啮齿动物和其他动物携带，通常通过吸入动物的干尿液和唾液感染人类。但在宏迪乌斯号邮轮上，汉坦病毒却在人际传播。

As for the African outbreak, scientists have made huge strides in fighting Ebola in recent years. They’ve created vaccines that can slow the spread of the disease and antiviral drugs that can cure infections.

至于非洲的疫情，科学家们近年来在对抗埃博拉方面已经取得了巨大进展。他们研发出了可以减缓疾病传播的疫苗，以及可以治愈感染的抗病毒药物。

But these treatments are probably going to be weak or useless. This is a very different Ebola virus.

但如今这些治疗方法可能起不到什么作用，甚至毫无用处。这是一种非常不同的埃博拉病毒。

What gives? There is a vast diversity of viruses, but we employ a limited vocabulary to talk about them. It would be just as confusing to treat blue whales like fruit bats and Siberian tigers, simply on the grounds that they’re all mammals.

这是怎么回事？病毒种类繁多，但我们用来讨论它们的词汇却很有限。这就好比因为蓝鲸、果蝠和东北虎都是哺乳动物，就把它们一概而论，同样会让人困惑。

Jens Kuhn, a virologist who serves on the International Committee on Taxonomy of Viruses, said that the recent outbreaks point to yawning gaps in our understanding of the so-called virosphere, the millions — perhaps even trillions — of virus species thriving around us.

国际病毒分类委员会成员、病毒学家延斯·库恩表示，最近的疫情表明，我们对所谓的“病毒圈”——在我们周围繁衍生息的数百万甚至数万亿种病毒——存在巨大的认识空白。

“These are case-use examples of why taxonomy is important,” he said. “Is something the same, or is it different? Well, if it’s different, then stuff we know about the other thing will not work on it.”

“这些实例恰恰说明了分类学的重要性，”他说。“某个病毒是相同的，还是不同的？如果它是不同的，那么我们对另一种病毒的知识就派不上用场了。”

Ebola viruses got their names from the site of one of the first documented outbreaks in 1976: the Ebola River, in what was then Zaire, now the Democratic Republic of Congo. When scientists examined blood from the victims, they isolated long, snakelike viruses distinct from any previously known.

埃博拉病毒得名于1976年首次记录在案的疫情暴发地之一埃博拉河。这条河位于当时的扎伊尔（现为刚果民主共和国）。科学家检测受害者血液，分离出长条状的蛇形病毒，与之前已知的任何病毒都截然不同。

本周，医护人员进入刚果鲁旺帕拉的一家埃博拉治疗中心。

But 1976 saw another outbreak that also caused deadly, bloody fevers — this one hundreds of miles to the east, in what was then Sudan, now South Sudan. The infected also harbored snakelike viruses.

但1976年还发生了另一起引发致命出血性发热的疫情——这次爆发地点在向东几百公里外的苏丹（现为南苏丹）。感染者体内同样带有蛇形病毒。

When scientists compared the viral genes, however, they found a striking number of differences. In later years, Ebola outbreaks occurred dozens of times, and in most cases the viruses resembled either the type first seen in Zaire or the type seen in Sudan.

然而，当科学家对比两种病毒的基因时，却发现了惊人的差异。在随后的几年里，埃博拉疫情爆发了数十次，而且在大多数情况下，这些病毒要么类似于最初在扎伊尔发现的类型，要么类似于在苏丹发现的类型。

Eventually, Dr. Kuhn and his colleagues formally recognized the two kinds of viruses as two distinct species. And, as taxonomists do in such cases, they gave each species a Latin name: Orthoebolavirus zairense and Orthoebolavirus sudanense.

最终，库恩和同事正式承认这两类病毒为两个不同的物种。并且，按照分类学家在这种情况下的惯例，他们给每个物种起了拉丁学名：Orthoebolavirus zairense（扎伊尔埃博拉病毒）和Orthoebolavirus sudanense（苏丹埃博拉病毒）。

But in the 50 years since the first Ebola outbreak, scientists have found other relatives of these viruses. In 2007, for example, 149 people in the Bundibugyo District of Uganda came down with hemorrhagic fevers, and 37 died.

但在首次爆发埃博拉疫情后的50年里，科学家们还发现了这些病毒的其他亲属。例如， 2007年，乌干达本迪布焦区有149人患上了出血热，其中37人死亡。

The virus they harbored was, genetically speaking, over 30 percent different from the viruses isolated in Zaire and Sudan — a new species, known now as Orthoebolavirus bundibugyoense.

从基因角度来说，他们体内携带的病毒与在扎伊尔和苏丹分离出的病毒存在超过30%的差异——这是一个病毒新种类，现在被称为Orthoebolavirus bundibugyoense（本迪布焦埃博拉病毒）。

The Bundibugyo virus caused a second small outbreak in 2012 before exploding back on the scene this month. The vaccines and the drugs that were developed for the Zaire species don’t work against the Bundibugyo virus, which belongs to a different evolutionary lineage. That’s one reason the new outbreak has public health experts so worried.

本迪布焦病毒在2012年引起过一次小型疫情，本月又再次集中暴发。针对扎伊尔病毒研发的疫苗和药物对本迪布焦病毒不起作用，因为该病毒属于不同的进化谱系。这也是公共卫生专家对新一轮疫情如此担忧的原因之一。

Hantaviruses also got their names from a river: the Hantan River, which flows through North and South Korea. It’s in a region where a mysterious kidney disease struck people every year. In 1978, researchers isolated the cause: a virus carried by striped field mice.

汉坦病毒同样得名于一条河流：流经朝鲜和韩国的汉江。在这一地区，一种神秘的肾脏疾病每年都会侵袭人们。1978年，研究人员分离出了病因：一种由黑线姬鼠携带的病毒。

这是一张名为Sin Nombre汉坦病毒的透射电子显微镜照片，该病毒曾于1993年在美国西部引发疫情。

Since then, scientists have discovered hantaviruses lurking in rodents and other mammals around the world. Some of them also cause kidney damage, while others strike the heart and the lungs.

自那以后，科学家们在世界各地的啮齿动物和其他哺乳动物中发现了潜伏的汉坦病毒。其中一些病毒会引起肾脏损害，另一些则会侵袭心脏和肺部。

The actor Gene Hackman’s wife, Betsy Arakawa, died at their New Mexico home last year after being infected with a type of hantavirus called Sin Nombre. Diagnosed earlier with Alzheimer’s, Mr. Hackman died days afterward.

演员吉恩·哈克曼的妻子贝特西·荒川（音）去年在他们新墨西哥州的家中因感染了一种名为Sin Nombre（无名）的汉坦病毒而去世。此前被诊断出患有阿尔茨海默症的哈克曼也在几天后去世。

As hantaviruses have adapted to rodents and other mammals across much of the world, they have evolved an enormous diversity — Dr. Kuhn and his colleagues recognize 38 species in the genus Orthohantavirus. (The Ebola genus, by contrast, includes only six species.)

随着汉坦病毒适应了世界上大部分地区的啮齿动物和其他哺乳动物，它们又演化出了巨大的多样性——库恩博士和同事在正汉坦病毒属中鉴定出了38个物种。（相比之下，埃博拉病毒属仅包含六个物种。）

Each species in turn may harbor a lot of diversity. As viruses replicate, strains can pick up new mutations that can drastically change their biology.

每个物种内部也可能包含大量的多样性。随着病毒的复制，不同毒株会产生新的突变，从而彻底改变其生物学特性。

The outbreak on M.V. Hondius this spring was caused by a species called Orthohantavirus andesense, carried by a number of rodents in South America. But there are four strains of this species; the outbreak was caused by one called Andes virus.

今年春天宏迪乌斯号邮轮上的疫情是由一个名为Orthohantavirus andesense（安第斯汉坦病毒）的病毒引起的，该病毒由南美洲的许多啮齿动物携带。但该物种有四个亚型；此次疫情是由其中一个名为安第斯的亚型引起的。

Unlike the other three strains — and unlike the 37 other species of hantaviruses — Andes virus can spread directly from one person to another.

与其他三个亚型不同——也与另外37种汉坦病毒不同——安第斯病毒可以直接人际传播。

“It seems like there are some mutations that under certain circumstances can make Andes virus person-to-person transmissible,” Dr. Kuhn said. No one knows what those mutations are.

“似乎有一些突变在某些情况下可以使安第斯病毒具备人际传播能力，”库恩说。目前没有人知道这些突变是什么。

本月早些时候，科学家和其他人员在阿根廷乌斯怀亚从捕鼠器中收集老鼠，以确定汉坦病毒是否已传播至该地区。

Dr. Kuhn suspects that the other strains related to Andes virus are lurking in rodents and share this ability to spread among people. After the M.V. Hondius outbreak, he predicts, scientists in Argentina and Chile will “go into their freezers with all the samples and sequence the crap out of everything and figure out — what are all these things?”

库恩怀疑，其他与安第斯病毒相关的毒株也潜伏在啮齿动物中，并同样拥有人际传播的能力。他预测，在宏迪乌斯号邮轮疫情之后，阿根廷和智利的科学家们将“翻出冷冻库里的所有样本，彻底对所有东西进行基因测序，搞清楚——这些东西到底都是些什么？”

As for Ebola, Dr. Kuhn expects more unpleasant surprises. He points to Orthoebolavirus taiense, also known as Taï Forest virus.

至于埃博拉，库恩博士预计会有更多令人不快的意外。他提到了Orthoebolavirus taiense（塔伊森林埃博拉病毒），也被称为塔伊森林病毒。

The first and last time anyone saw this species was in 1994, when it infected a scientist dissecting a dead chimpanzee. She developed Ebola symptoms but eventually recovered.

人们第一次也是最后一次见到该病毒是在1994年，当时它感染了一名正在解剖一只死黑猩猩的科学家。她出现了埃博拉症状，但最终康复了。

“I’m sure it’s still out there, but nobody focuses on it because it caused only one case,” Dr. Kuhn said. “I think that’s a big mistake.”

“我确定它仍然存在于自然界中，但没人关注它，因为它只引发了一个病例，”库恩说。“我认为这是一个巨大的错误。”

Other Ebola-like species that have yet to be discovered and named may be lurking in African animals. The classification system that Dr. Kuhn has helped create will hopefully make it an easier process.

其他尚未被发现和命名的埃博拉类病毒可能正潜伏在非洲动物体内。库恩参与创建的分类系统有望让这一过程变得更加容易。

He doesn’t expect people to learn to rattle off Orthohantavirus andesense and other Latin names in casual conversation. But instead of referring to the cause of the outbreak in Africa as the Ebola virus, he suggests calling it Bundibugyo virus. (It’s pronounced boon-dee-boo-joh.)

他不指望人们在日常交谈中能脱口说出Orthohantavirus andesense之类拉丁学名。但是，他建议不要将此次非洲疫情的起因统称为“埃博拉病毒”，而是称其为“本迪布焦病毒”。

“The moment you mix up Bundibugyo virus and Ebola virus, the impression will be, ‘Oh, we’ve got something for that,’” Dr. Kuhn said. “But we don’t.”

“一旦你把本迪布焦病毒和埃博拉病毒混为一谈，给人的印象就会是：‘哦，我们有办法对付它，’”库恩说，“但实际上，我们没有。”