曾令医学界感到欣慰的一些得到有效控制的感染性疾病,近些年又卷土重来,而且成为令常规药物无能为力的棘手问题。虽然目前不少国家,特别是发达国家,排在死因前列的是癌症、心脏病和意外事故等,但就全世界或某些国家、地区而言,感染性疾病依然是人类死亡的最主要原因。1991年,全世界死于呼吸道感染疾病的儿童就达430万人;死于腹泻疾病和疟疾的分别为350万和100万;每年发生的新的结核病患者为800万,其中290万人死亡。 In some years, some effectively controlled infectious diseases that have rewarded the medical profession have come back and become a thorny issue that makes conventional drugs incapable. Although many countries, especially developed countries, rank among the leading cause of death cancer, heart disease and accidents, infectious diseases are still the most important cause of human death in the world or certain countries and regions . In 1991, there were 4.3 million children died of respiratory tract infections worldwide; 3.5 million and 1 million died of diarrheal diseases and malaria; and 8 million new tuberculosis patients each year, 2.9 million of them died.