Exotic Newcastle disease

Exotic Newcastle disease

来源：环球雅思网 www.ielts.com.cn 2005-6-14

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    I'm Gwen Outen with the VOA Special English Agriculture Report.

    Exotic Newcastle disease is a viral infection that spreads easily among birds. The disease causes breathing problems in birds and often leads to death. Other effects could include loss of muscle control, digestive problems or a drop in egg production. 

    The disease is not known to harm people. Experts say the only way to fight exotic Newcastle disease is to destroy infected birds. Infected birds must also be kept away from any other birds. Quarantine measures are needed around affected areas in an effort to contain the spread of the virus. In 2003, parts of California, New Mexico, and Texas faced quarantines for exotic Newcastle disease. Currently, no such quarantines are in place in the United States. 

    In late May in Brazil, about 5000 chickens died from a disease on a farm in the state of Mato Grosso do Sul. The Associated Press reported that officials in Brazil did not make the news public for several days. The news agency said Brazilian health officials ordered the destruction of 17,000 chickens. They also ordered roadblocks around the farm, which is near the town of Jaraguari. Officials were concerned about the possibility of bird influenza. The H5N1 form of bird flu has killed more than 50 people in Asia, including 38 in Vietnam. East Asian countries have had to destroy large numbers of chickens and other farm birds. 
On June 1st however, a Brazilian official told the Associated Press that the virus is not bird flu. He said testing continued but officials suspect that it may be exotic Newcastle disease. That disease can come from tropical birds like Amazon parrots. Infected Amazon parrots can carry the virus for up to 400 days without showing signs of sickness. 
    The possibility of the spread of disease means it is important to keep farm birds separated from wild birds and pet birds. But, at the same time, officials also say that wild birds should not be destroyed in an effort to protect farm birds. 
    On May 21st, China informed the World Organization for Animal Health about the deaths of 500 wild birds in Qinghai Province. Chinese officials said the H5N1 virus was responsible. 
    This VOA Special English Agriculture Report was written by Mario Ritter. Our reports are on the web at voaspecialenglish.com. I'm Gwen Outen.
    Vocabulary: 
    quarantine: enforced isolation or restriction of free movement imposed to prevent the spread of contagious disease（隔离，为防止传染病传播而强制施行的隔离制度）