Efforts to increase food production in Africa may be increasing the risk of plague infection. Plague has been killing people for hundreds of years. A new report looks at efforts to clear land for farming in natural, undeveloped areas of Tanzania. The report links the development of natural lands into croplands to a sharp increase in the number of rats. It warns the animals often carry insects infected with plague.
非洲努力提高粮食产量可能会增加鼠疫感染的风险。鼠疫已经危害人类数百年。一份新报告考察了坦桑尼亚天然的、欠发达的地区清理土地用于耕种的各项成就。该报告把天然土地转为农田的发展现状与老鼠数量急剧增加联系了起来，并警示这种动物通常携带了被鼠疫感染的昆虫。
Many people become frightened when they hear the word "plague." One of the most famous periods of plague death was known as the "Black Death." It was a time 700 years ago when the disease killed more than 25 million people in Europe.
许多人一听到鼠疫这个词就心生恐惧。最有名的一个阶段鼠疫被称之为黑死病。这是700年前，当时欧洲有超过2500万人死于这种疾病。
Health officials do not believe plague will kill many people in Africa. But they are worried about the rising number of plague infections. Thirty to 60 percent of those infected will die if they are not given medicine.
卫生官员不认为鼠疫会让很多非洲人致死。但他们担心鼠疫感染数量不断提升。如果不吃药，30%到60%的感染者会死亡。
Plague is caused by bacterium. It is passed between animals and humans through the bite of an inflected flea or by touching an infected animal. Rats often carry fleas. The insects feed on the blood of an infected rat.
鼠疫是由细菌引起的。它通过被感染跳蚤的叮咬或接触感染动物在动物和人之间传播。老鼠通常携带跳蚤，这种昆虫以被感染老鼠的血液为食。
There are three forms of plague. The most common is bubonic plague. This was the disease that spread in Europe during the 14th century. Bubonic plague causes enlargement of lymph nodes. The lymphatic system is the part of the body's natural defense system against disease.
鼠疫存在三种类型。最常见的是腺鼠疫。这就是14世纪在欧洲传播的疾病。腺鼠疫导致淋巴结肿大。淋巴系统是人体对抗疾病的天然防御系统的一部分。
If the plague infection is not treated, the bacteria can reach the lungs. Then, the person may develop pneumonic plague. This is the least common but most aggressive form of the disease. It can be easily spread through small droplets expelled from the person's nose or mouth. A person infected with bubonic plague cannot infect others.
如果这种鼠疫感染未得到治疗，细菌就会到达肺部。然后这个人可能就会患上肺鼠疫。这种疾病类型不太常见但最为活跃。它可以很容易地通过从人的鼻子或嘴巴喷出的细小液滴传播。而腺鼠疫感染者无法传染他人。
The World Health Organization says pneumonic plague is one of the most deadly infectious diseases. People suffer high body temperature, shaking, pain, weakness, and muscle and joint pain within two to three days of being infected.
世界卫生组织表示，肺鼠疫是最致命的传染病之一。感染者两到三天内就会发烧、寒战、疼痛、无力、肌肉和关节疼痛。
Antibiotic drugs can cure the disease. But the infected individual must take them very quickly, because pneumonic plague can kill people within 24 hours after infection. The WHO says only a small number of reported cases are of the pneumonic form.
抗生素可以治疗这种疾病。但是感染者必须尽快服用抗生素，因为肺鼠疫感染24小时之内就能致人死亡。世界卫生组织表示，只有少数报告病例属于肺鼠疫。
Kristofer Helgen is with the Smithsonian Institution's Museum of Natural History in Washington, D.C. He helped to write the new report. It was published online in the American Journal of Tropical Medicine and Hygiene. He spoke to VOA about the disease.
克里斯多佛·赫尔根（Kristofer Helgen）就职于史密森学会下属的华盛顿自然史博物馆。他帮助撰写了这份新的报告。该报告发表在《美国热带医学与卫生杂志》网络版。他对美国之音谈到了这种疾病。
"It maybe surprises people to learn that plague remains a public health concern in various parts of the world -- especially in Africa south of the Sahara. Plague circulates in small mammals and rodents. And when the conditions are right, it's a disease that can spread to people and it can still be a deadly disease. Now, plague is a disease that is treatable with antibiotics. And in that regard, it's considerably maybe less scary, less alarming than other emerging diseases like Ebola. But we should remember that this is a disease that is still on the ground in Africa and remains a public health concern."
他说，“鼠疫仍然是世界上很多地区，尤其是撒哈拉沙漠以南非洲的一项公共健康问题，这也许会让很多人惊诧。鼠疫在小型哺乳动物和啮齿动物之中传播。当条件合适时，它就能传播给人类，成为一种致命疾病。现在鼠疫可以用抗生素治疗。而从这方面来说，它远没有埃博拉之类的新兴疾病那么可怕和恐慌。但我们应该记住，这种疾病仍然在非洲存在，仍然是一项公共健康问题。”
Mr. Helgen says the amount of farmland in northern Tanzania has risen sharply in recent years. By his estimate, the croplands have expanded by 70 percent. He and other researchers also attempted to estimate the number of rats in areas where maize was planted. They found the rat population doubled in those areas, compared to neighboring land that had not been developed for agriculture.
赫尔根先生表示，坦桑尼亚北部的农田数量近年来急剧上升。据他估计，农田已经扩大了70%。他和其他研究人员还尝试估算了玉米种植地区老鼠的数量。他们发现，与周边尚未开发成农田的地区相比，这些地区的老鼠数量增加了一倍。
Mr. Helgen says that as the amount of farmland increases, so does the number of rats. He notes that the animals and people often live in the same areas, which makes it easier for plague to spread.
赫尔根先生表示，由于耕地数量增加，老鼠数量也随之增加。他指出，这些动物和人类通常生活在同一地区，这使得鼠疫更容易蔓延。
"And this is an animal that we often will call a commensal rodent species. And literally that word commensal means 'eating from the same table' -- in other words, the notion that this is a rat that does go into peoples' houses and villages and interacts with people in their living spaces."
他说，“这种动物我们通常称之为共生啮齿类动物。共生这个词的字面意思就是‘同桌吃饭’。换句话说就是，老鼠会进入人类的房屋和村庄，侵入人类的生活空间。”
He notes that rats have a major effect on peoples' lives. The animals eat people's food, spread disease and make it more difficult for farmers to succeed.
他指出，老鼠对人类生活具有重大影响。这种动物食用人类的食物，传播疾病，并让农民们更难获得好收成。
The plague never completely disappears. It may stay in the wild for 10 or 20 years. Then, something happens and the number of rats increases. The disease then begins to spread in agricultural areas, then to towns and cities. Many people in an area may die, but the disease rarely spreads outside a country. Only people within a limited area are infected. When the number of cases begins to decline, scientists will say "the outbreak has been contained."
鼠疫永远不会完全消失。它可以在野外维持10到20年。然后，发生了什么事情，老鼠数量增加。然后这种疾病开始在农业地区传播，然后蔓延到城镇。可能某个地区的很多人会死亡，但这种疾病很少蔓延到一国之外，只有特定地区的人们会被传染。当病例数开始下降，科学家们就会说，“鼠疫爆发得到了遏制。”
The World Health Organization says people should not be afraid of the plague. It says scientists have developed modern and effective ways to prevent, treat and cure the ancient disease.
世界卫生组织表示，人们不应该害怕鼠疫。该组织表示，科学家们已经研发出现代和有效的方式来预防、治疗并治愈这种古老的疾病。
I'm Christopher Jones-Cruise.
我是克里斯托弗·琼斯 - 克鲁斯（Christopher Jones-Cruise）。(51VOA.COM对本文翻译保留全部权利，未经授权请勿转载，违者必究！)