关键词: 云南省, 恙虫病, 流行病学, 监测

Abstract: Objective To analyze the disease distribution characteristics of scrub typhus in Yunnan Province, China from 2013 to 2022, so as to provide scientific evidence for formulating prevention and control strategies for scrub typhus.Methods By using descriptive epidemiological methods and visual analysis in ArcGIS 10.3 software, the data about scrub typhus in Yunnan Province from 2013 to 2022 were systematically analyzed to determine the epidemiological characteristics, spatiotemporal distribution, and high-risk areas of scrub typhus in Yunnan Province.Results A total of 69 246 cases of scrub typhus were reported in Yunnan Province from 2013 to 2022, including 19 deaths. The average annual incidence rate was 14.58/100 000. The annual incidence rate showed a rapid increase over the years, from 5.95/100 000 in 2013 to 25.53/100 000 in 2022 (χ²_trend=30.573, P<0.001). The fatality rate was 0.036 %. The number of affected counties or districts increased from 70 in 2013 to 97 in 2022. The top three regions by incidence rate were the Dehong Dai and Jingpo Autonomous Prefecture (10 906, 85.14/100 000), Lincang (13 677, 55.67/100 000), and Baoshan (13 406, 52.44/100 000). The average annual growth rate of new cases was 17.82 %. The top three regions by average annual growth rate were the Nujiang Lisu Autonomous Prefecture (84.15 %), Qujing City (48.91 %), and the Wenshan Zhuang and Miao Autonomous Prefecture (45.12 %). In 2013, the areas with high incidence were mainly concentrated in the western and central part of Yunnan Province, but since 2019, the hotspots gradually spread to the southeastern part. In general, the incidence of scrub typhus was higher in males (χ²=332.635, P<0.001). The cases were more in the age group of 0-<5 and 50-<55 years accounting for 11.05 % and 11.19 %, respectively, more among farmers, and more in summer and autumn. The cases were mainly reported by county/district-level hospitals (56.44 %). The median time from disease onset to diagnosis was 4 days. Hospitals at higher levels were associated with a shorter time from onset to diagnosis (H=15.924, P<0.001). Clinically diagnosed cases accounted for 96.06 % of the total number.Conclusions The incidence of scrub typhus has shown an increasing trend in Yunnan Province, and tended to spread from western and central regions to southeastern regions. Scrub typhus occurs frequently in May and June, and is more prevalent in middle-aged and elderly female farmers. In recent years, the number of cases reported by township-level hospitals has increased remarkably. It is necessary to strengthen training of primary care doctors and health education for residents and tourists.

Key words: Yunnan Province, Scrub typhus, Epidemiology, Surveillance