与所有传染病一样 ,只有传染源、传播途径、易感人群三者同时存在条件下麻疹才得以发生和传播。麻疹的发生和传播依赖於麻疹易感者的存在 ,过去麻疹呈周期性流行亦源于麻疹易感者周期性的积累。当今控制麻疹的主要措施是通过对麻疹易感者接种麻疹疫苗 (ＭＶ ) ,使其获得免疫 , Like all infectious diseases, measles can only occur and spread under the condition that the source of infection, the route of transmission, and the susceptible population exist simultaneously. The occurrence and spread of measles depends on the presence of measles susceptible persons. In the past, the periodic epidemic of measles also resulted from the cyclical accumulation of measles susceptible persons. The main measure nowadays to control measles is immunization of measles vaccinees by vaccination of measles vaccines,