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1、By Cynthia Kirk and Jerilyn Watson2011-11-21Photo: AP Biohazard investigators outside the Dirksen Senate office building in Washington in October of 2001BARBARA KLEIN: This is SCIENCE IN THE NEWS, in VOA Special(特别的) English. Im Barbara Klein.CHRISTOPHER CRUISE: And Im Christopher Cruise. Today we t
2、ell about the deadly disease anthrax.(MUSIC)BARBARA KLEIN: Ten years have passed since letters containing（包含） anthrax bacteria （细菌）passed through the mail in the United States. The anthrax particles （粒子系统）looked like harmless white powder（粉末）. But the bacteria killed five people.No one knew who mail
3、ed（邮寄） the letters. News organizations and congressional（国会的） offices were the main targets（目标）. And, the anthrax particles also found their way to the home of a ninety-four-year-old woman.APA photograph of the letter containing anthrax that was sent to Senate Majority Leader Tom DaschleYears later,
4、 federal investigators named a scientist, Bruce Edwards Ivins, as the only suspect（可疑的/嫌疑犯） in the murders. He was an anthrax expert（熟练地） who worked at the biological defense （防护）center in Maryland（马里兰）, where the bacteria was kept. The government was preparing to charge （控告）him when he killed himse
5、lf in two thousand eight.CHRISTOPHER CRUISE: Recently（最近）, an investigation（调查研究） requested by Congress suggested that Bruce Ivins may have been falsely（错误的） suspected. Other investigators and news organizations also have studied the case and questioned the evidence （证据）against Mr. Ivins.Government
6、lawyers say there is no reason for debate（辩论）. The lawyers say they know they found the right person. But questions about the case have caused concern among some people. They believe that if Bruce Ivins was innocent（无罪的）, the person who sent the letters containing anthrax might still be free.BARBARA
7、 KLEIN: Anthrax also is the subject（主题） of another current debate. An expert advisory（劝告） committee（委员会） has proposed（被提议） testing a vaccine（疫苗） against anthrax on children. Currently, medical（医学的） workers are giving the vaccine to some adults. But it has not been tested（经过考验的） on children. The goal
8、 of the possible testing would be to learn if children could be protected from the disease in the event of a terrorist attack.The National Biodefense Science Board proposed the testing to the United States Department（部门） of Health and Human Services. The Board noted the ethical questions involved. B
9、ut it said it would suggest approval （赞成）of the tests if those questions could be settled.Some health-activist groups and others immediately（直接的） protested（抗拒） the possible tests. The Obama Administration has said the issue will remain under study.CHRISTOPHER CRUISE: The anthrax vaccine has been ava
10、ilable for years on a limited basis. It is given mainly to members of the armed（武装的） forces（势力）. More than two million armed forces members have had the vaccine. It is generally considered safe. But there have been protests about unexpected（意外的/想不到的） side effects（效果）. People who work with animals al
11、so can be vaccinated against anthrax.Anthrax cannot be passed from one person to another. However, anthrax affects（影响） cattle （牛）and other creatures that eat plants. It also can affect people who deal with infected animals or animal products.APA microscopic view of stained anthrax bacteriaAnthrax is
12、 found naturally in the environment. It is caused by the bacterium Bacillus anthracis (pron., an THRA sis). The bacteria have spores or protective coverings（遮盖物）. Spores are like seeds. They can live for hundreds of years in the soil（土壤）. They can survive through severe heat, dry weather, and other
13、extreme（极端的） conditions.(MUSIC)BARBARA KLEIN: Anthrax can be found anywhere in the world. It is most common(普通的) in developing countries. Animals can get the bacteria while eating plants. That can loosen（放松） anthrax spores in the soil. The animal eats or breathes in the spores and may become infecte
14、d. But a vaccine can protect animals.In people, the disease can appear in three forms: cutaneous（皮肤的） anthrax, intestinal anthrax and inhalation （吸入的）anthrax.Cutaneous（皮肤的） anthrax is the most common kind of infection. People can become infected this way if the bacteria enter through a cut in the sk
15、in. The disease is most often found among people who work with infected animals or animal products. Cutaneous anthrax causes a painful, black area on the skin. However, it rarely causes death.CHRISTOPHER CRUISE: Intestinal anthrax results from eating infected meat. It can cause high body temperature
16、, stomach（胃） pain and expulsion（驱逐） of food from the stomach. It often can be cured（治愈的）.The most severe form of the disease is inhalation （吸入）anthrax. This happens when a person breathes the spores into the lungs. Inhalation anthrax is most often found among people who work with animal hair and wool in areas where the disease affects animals.Inhalation anthrax is deadly if a person breathes in thousands of extremely （非常的，极端的）small spor
