伤寒几乎总是由于摄入了被伤寒病人或携带者排泄物所污染的食物或饮水而引起。人类是伤寒杆菌的唯一宿主。虽然许多国家已控制了本病的传播,但在世界上其他许多国家里本病仍然是一种严重影响人们健康的疾病,每年有几十万病例发生。伤寒的控制主要靠改善卫生设施,特别是洁净的饮水供应和对污水、污物的良好处理。此外,还要注意发现慢性携带者,并对其和伤寒病人进行抗菌治疗。虽然用灭活的伤寒菌苗皮下注射能增强人类抵抗伤寒的能力,但不是控制本病的主要手段,因为用这 Typhoid fever is almost always caused by the ingestion of food or water contaminated with excrement of typhoid-infected patients or carriers. Humans are the sole host of typhoid bacilli. Although many countries have controlled the spread of the disease, the disease is still a serious disease affecting people in many other countries of the world, with hundreds of thousands of cases occurring each year. Control of typhoid fever mainly relies on improving sanitary facilities, especially clean drinking water supplies and good treatment of sewage and dirt. In addition, care should be taken to detect chronic carriers and treat them with typhoid fever. Although subcutaneous injections with inactivated typhoid bacilli enhance the ability of humans to fight typhoid, they are not the primary means of controlling this disease because