1 背景二十世纪中叶以来,世界上普遍存在一种乐观情绪,认为人类已经赢得了对传染病斗争的胜利,天花已在世界范围消灭,一些长期威胁人类健康的传染病如鼠疫、霍乱、伤寒、乙脑、白喉、百日咳、脊髓灰质炎等已经有效控制。人们似乎认为,曾给人类带来深重灾难的瘟疫将仅仅是在记忆中的魔影。然而,自1973年以来,新出现的病原体及相关疾病已达30多种,一些已得到控制的传染病又 1 Background Since the middle of the 20th century, there has been a general optimism in the world that human beings have won the victory over the fight against communicable diseases. Smallpox has been eliminated around the world. Some infectious diseases that long threaten human health, such as plague, cholera and typhoid , JE, diphtheria, whooping cough, poliomyelitis, etc. have been effectively controlled. People seem to think that the pestilence that has brought catastrophe to mankind will only be the shadow in memory. However, since 1973, more than 30 new pathogens and related diseases have emerged. Some of the controlled infectious diseases