目的探讨甘肃省部份地区发生麻疹爆发或流行的原因,分析麻疹减毒活疫苗(MV)效力与麻疹发病之间的关系。方法选择4个县进行1∶1配对病例对照研究。结果共调查病例和对照各358人,病例中<7岁儿童占27.65%,7~14岁占66.48%,平均年龄8.62岁。病例组MV接种率36.87%,对照组MV接种率89.94%;接种MV后≥5年发病者占68.94%,7~9岁发病儿童距接种MV≥5年的占74.47%。1∶1配对病例对照研究计算,接种MV与麻疹发病的比值比95%可信区间为0.028~0.079,MV效力95%可信区间为92.1%~97.2%。结论甘肃省部份地区发生麻疹爆发或流行的主要原因是MV接种率过低,存在免疫空白。提高MV接种率,缩短MV 2针接种间隔时间,适时开展MV强化免疫可有效控制麻疹。 Objective To investigate the causes of measles outbreaks or epidemics in some areas of Gansu Province and to analyze the relationship between the efficacy of live attenuated measles vaccine (MV) and the incidence of measles. Methods Four counties were selected for 1: 1 matched case-control study. Results A total of 358 cases and controls were investigated. Among them, <7 years old children accounted for 27.65%, 7-14 years old accounted for 66.48%, with an average age of 8.62 years. MV vaccination rate was 36.87% in the case group and 89.94% in the control group. 68.94% of the patients were vaccinated ≥ 5 years after inoculation, and 74.47% of the children aged 7-9 were vaccinated with MV ≥ 5 years. 1: 1 paired case control study calculated that the vaccination MV and measles incidence odds ratio 95% confidence interval of 0.028 to 0.079, MV efficacy 95% confidence interval of 92.1% to 97.2%. Conclusion The main reason of the outbreak or epidemic of measles in some areas of Gansu province is the low vaccination rate of MV and the immunization blank. Improve the MV vaccination rate, shorten the MV 2 needle inoculation interval, timely launch of MV enhanced immunity can effectively control measles.