伤寒是发展中国家和地区的常见病。这些地区的改水、改厕任务艰巨,短期内很难解决好。注射伤寒Ｖｉ菌苗是预防伤寒的一个有效措施。贵州省某所实行伤寒Ｖｉ菌苗(以下简称Ｖｉ菌苗)接种制度,即对所有人员都注射Ｖｉ菌苗,从1998年元月起所内陆续出现伤寒病人,呈现爆发流行,经调查 Typhoid fever is a common disease in developing countries. Water improvement in these areas is an arduous task to change lavatories and it is hard to solve them in a short period of time. Injecting Typhoid Vi vaccine is an effective measure to prevent typhoid fever. In Guizhou Province, a vaccination system for typhoid Vi bacterin (hereafter referred to as Vi bacterin) has been in place in Guizhou Province. All patients were vaccinated with Vi bacilli. Typhoid fever patients were continuously exposed from January 1998 onwards. After investigation,