目的了解西安市麻疹发病的实际情况,探讨接种麻疹疫苗(MV)后病例的流行病学特征和发病的主要原因。方法开展回顾性流行病学调查,并采集病例静脉血3~5ml,进行麻疹IgM复核和IgG检测。结果西安市2004年12月麻疹病例较近年同期明显增多,而且病例中流动、常住人口分别占45.1%、54.9%;免疫后的流动、常住人口病例在发病年龄上无差异;免疫后病例与未免疫、免疫史不详病例的流行病学特征无差异,但抗体几何平均滴度免疫后高于未免疫者;麻疹发病的主要原因为免疫空白,接种技术、使用剂量、疫苗储运等因素也是引起发病的原因之一。结论做好MV的初种是控制麻疹发病的关键;变更MV免疫程序,将复种年龄提前到18~24月龄、接种剂量增加到0.5ml是必要的技术措施。 Objective To understand the actual situation of measles in Xi’an and to explore the epidemiological characteristics of the measles vaccine (MV) and the main causes of the disease. Methods A retrospective epidemiological investigation was carried out and 3 ~ 5ml of venous blood samples were collected for measles IgM and IgG detection. Results The cases of measles in December 2004 in Xi’an City were significantly increased compared with the same period of last year, and the number of floating and permanent residents in the cases accounted for 45.1% and 54.9% respectively. There was no difference in the age of onset between the immunized and the resident population after vaccination. Epidemiological characteristics of patients with unknown history of immunization and immunization showed no difference, but the geometric mean titer of antibody was higher than that of non-immunized people after immunization. The main causes of measles were immune blank, vaccination technique, dosage, vaccine storage and other factors One of the causes of the disease. Conclusion It is the key to control the incidence of measles in the early stage of MV. To change the procedure of MV vaccination, the age of multiple resuscitation should be advanced to 18-24 months old. It is necessary to increase the inoculation dosage to 0.5ml.