摘要目的:分析2011—2024年山东省流行性乙型脑炎（Japanese encephalitis，JE；简称乙脑）流行病学特征，为防控工作提供科学依据。方法:通过中国疾病预防控制信息系统收集2011—2024年JE病例，进行描述性流行病学分析，采用SPSS26.0软件分析不同年龄组和性别间的病情转归结果，对部分病例脑脊液标本进行乙型脑炎病毒（Japanese encephalitis virus，JEV）核酸检测和PrM基因的测序分析。结果:山东省2011—2024年共报告JE病例1 001例，年均发病率0.72/100万，死亡38例，病死率为3.80%（38/1 001），发病高峰出现在8~10月。年均发病率居前5位的市分别是泰安、德州、聊城、淄博和滨州。0~14岁、15~39岁、≥40岁分别占发病人群的30.07%（301/1 001）、15.08%（151/1 001）和55.05%（549/1 001），农民发病人数最多为479人，其次为学生193人。在随访的984例病例中，发病6个月后的平均痊愈率为53.25%（524/984），后遗症发生率为29.17%（287/984），病死率为17.58%（173/984）；不同性别和年龄组间的转归结果存在统计学意义（ Z=-2.38， P=0.017；趋势 χ 2=122.61， P<0.001）。对186份JE确诊病例脑脊液标本进行核酸检测，其中11份阳性，6份PrM基因成功测序，显示均为基因1型。 结论:随着扩大免疫规划工作的持续推进，山东省JE发病率显著下降，发病年龄结构以成人为主，流行季节仍集中于夏秋季，后遗症发生率和病死率高。为此，应进一步开展针对成人的JE疫苗接种相关研究，并持续加强高发地区，尤其是农村地区的JE监测与防控工作。

abstractsObjective:To analyze the epidemiological characteristics of Japanese encephalitis（JE）in Shandong province from 2011 to 2024，and provide a scientific basis for prevention and control work.Methods:We obtained data on JE cases reported during 2011-2024 to the China Information System for Disease Control and Prevention and conducted a descriptive epidemiological study. SPSS 26.0 software was used to analyze follow-up outcomes among different age groups and genders. Real-time PCR and PrM of Japanese encephalitis virus（JEV）sequencing were performed for cerebrospinal fluid（CSF）specimens of patients.Results:A total of 1 001 JE cases were reported during 2011-2024，for an annual average incidence of 0.72 cases per 1 000 000 population；38 JE-related deaths occurred，for a case-fatality rate of 3.80%（38/1 001）. The peak incidence occurs from August to October. The five highest provincial incidence rates were reported in Tai'an，Dezhou，Liaocheng，Zibo and Binzhou；age groups 0-14，15-39，and ≥ 40-year-olds accounted for 30.07%（301/1 001），15.08%（151/1 001），and 55.05%（549/1 001）of cases，respectively. Farmers had the highest number of cases at 479，followed by students with 193. Among 984 followed-up cases，the average recovery rate，the sequelae rate，and the case fatality rate at 6 months after the onset of the disease were 53.25%（524/984），29.17%（287/984），and 17.58%（173/984），respectively. There were statistically significant differences in outcomes among different age and sex groups（ Z=-2.38， P=0.017；trend χ2=122.61， P<0.001）. Of the 186 CSF specimens from confirmed JE cases，11 were positive by nucleic acid amplification，and 6 that were successfully sequenced for the PrM gene were identified as Genotype Ⅰ. Conclusions:The continued implementation of the Expanded Program on Immunization has led to a marked decline in JE incidence in Shandong province. Adults now constitute the main affected population. The disease remains seasonal，with high sequelae and fatality rates. These findings highlight the need for research into adult JE vaccination and for enhanced surveillance and control，especially in high-risk rural areas.