Epidemiological characteristics of scrub typhus in Dehong Dai and Jingpo Autonomous Prefecture, Yunnan Province from 2010 to 2024

doi:10.12140/j.issn.1000-7423.2025.05.013

Abstract

Abstract:

Objective To investigate the epidemiological characteristics of scrub typhus in Dehong Dai and Jingpo Autonomous Prefecture, Yunnan Province from 2010 to 2024, so as to provide insights into optimization of scrub typhus control strategies. Methods Data on scrub typhus cases reported in Dehong from January 1, 2010, to December 31, 2024 were collected from the China Disease Prevention and Control Information System. The Joinpoint Regression Program version 5.3.0 was used to establish a Joinpoint regression model. The annual percent change (APC), average annual percent change (AAPC), and their 95% confidence intervals (CI) of the incidence of reported scrub typhus were calculated to analyze the trends in incidence by gender, region, and age group. Normality tests and descriptive statistical analyses were performed using the software SPSS 25.0. Results A total of 13 715 scrub typhus cases were reported in Dehong from 2010 to 2024, with no deaths, and the annual average reported incidence was 71.88/10⁵. The number of reported cases and reported incidence appeared an overall tendency towards a rise from 2010 to 2022, with an increase from 117 cases (9.84/10⁵) in 2010 to 1 817 cases (138.76/10⁵) in 2022. A slight decline was observed in 2023 (1 644 cases, 124.47/10⁵) and 2024 (1 457 cases, 108.97/10⁵), although the incidence remained high. There were significant differences in the number of reported cases and the incidence among years (χ² = 5 318.62, 4 783.42; both P < 0.01). Joinpoint regression analysis identified two turning points (in 2016 and 2022) and the trends in incidence were divided into three phases: a significant increase from 2010 to 2016 (APC = 33.61%, P < 0.01), a continued but slower increase from 2017 to 2022 (APC = 13.94%, P < 0.01), and a numerical decline from 2023 to 2024 (APC = -10.74%, P > 0.05). Mangshi, Yingjiang County and Longchuan County were high-incidence areas from 2010 to 2024, with 4 826 (35.19%), 3 921 (28.59%), and 3 151 (22.97%) reported cases, and average annual incidence rates of 77.57/10⁵, 84.83/10⁵, and 112.80/10⁵, respectively. Joinpoint regression analysis indicated that the reported incidence appeared a tendency towards a significant rise across all counties (cities) from 2010 to 2024 (all P < 0.01 for AAPC), with the largest increase seen in Lianghe County (AAPC = 48.00%), followed by Longchuan County (AAPC = 38.64%), Ruili City (AAPC = 22.57%), Mangshi (AAPC = 18.47%), and Yingjiang County (AAPC = 9.14%). A distinct seasonal pattern was observed in the incidence, with the peak in August (seasonal index = 2.65). The epidemic season was found from July to November, with the number of reported cases accounting for 84.81% (11 632/13 715) of the total reported cases. There were 7 799 (56.86%) male cases and 5 916 (43.14%) female cases, with a male-to-female ratio of 1.32 : 1, and the trends in incidence among both genders were consistent with the overall trend, with 2016 and 2022 as key turning points. Cases were widely distributed across all age groups, ranging from 1 month to 96 years, with a median age of 40 years. The majority of cases (55.49%, 7 611/13 715) were young and middle-aged adults aged 30 to 59 years. Joinpoint regression analysis revealed a significant increase in incidence across all age groups from 2010 to 2024 (all P < 0.01 for AAPC), with the largest increase seen among residents at ages of 40 to 49 years (AAPC = 19.41%, 95% CI: 17.36 to 24.60). Farmers were the dominant occupation (9 969 cases, 72.69%). Conclusion The incidence of scrub typhus appeared an overall tendency towards a rapid rise in Dehong from 2010 to 2024. Continuous improvements of disease surveillance and control is recommended tailored to high-risk regions, epidemic seasons, and high-risk populations.

Key words: Scrub typhus, Epidemiological characteristic, Temporal trend, Joinpoint regression analysis

CLC Number:

R376.2

GOU Changchun, LIU Aicong, FENG Kai, CAO Chunli, SONG Xiaoxiao, YUE Taike. Epidemiological characteristics of scrub typhus in Dehong Dai and Jingpo Autonomous Prefecture, Yunnan Province from 2010 to 2024[J]. CHINESE JOURNAL OF PARASITOLOGY AND PARASITIC DISEASES, 2025, 43(5): 683-689.

Figures/Tables 3

References 32

[1]	Paris DH, Shelite TR, Day NP, et al. Unresolved problems related to scrub typhus: A seriously neglected life-threatening disease[J]. Am J Trop Med Hyg, 2013, 89(2): 301-307.
[2]	中国微生物学会人兽共患病病原学专业委员会, 中国医药生物技术协会生物诊断技术分会, 姜天俊, 等. 恙虫病临床诊疗专家共识[J]. 中国人兽共患病学报, 2024, 40(1): 1-6.
	Society of Microbiology Committee on Zoonotic Pathogens Chinese, Technology Branch of China Medical Biotechnology Association Biodiagnostic, Jiang TJ, et al. Expert consensus on the clinical diagnosis and treatment of scrub typhus[J]. Chin J Zoonoses, 2024, 40(1): 1-6. (in Chinese)
[3]	Chaisiri K, Linsuwanon P, Makepeace BL. The chigger microbiome: Big questions in a tiny world[J]. Trends Parasitol, 2023, 39(8): 696-707.
[4]	朱师晦, 张孝, 曾梅辉, 等. 广州市恙虫病流行之报告[J]. 中华医学杂志, 1950, 36(10): 421-423.
	Zhu SH, Zhang X, Zeng MH, et al. Epidemiological report of scrub typhus in Guangzhou, China[J]. Natl Med J China, 1950, 36(10): 421-423. (in Chinese)
[5]	毕树云, 徐洪丽, 杨猛贤, 等. 云南省南涧县41例恙虫病报告[J]. 中国寄生虫学与寄生虫病杂志, 2002, 20(5): 277, 280.
	Bi SY, Xu HL, Yang MX, et al. A report of 41 cases of tsutsugamushi disease in Nanjian County, Yunnan Province[J]. Chin J Parasitol Parasit Dis, 2002, 20(5): 277, 280. (in Chinese)
[6]	吴中发, 邓海智, 苏子林, 等. 赣州市发现恙虫病5例[J]. 中国寄生虫学与寄生虫病杂志, 2006, 24(5): 398-399.
	Wu ZF, Deng HZ, Su ZL, et al. Five cases of tsutsuganushi disease in Ganzhou[J]. Chin J Parasitol Parasit Dis, 2006, 24(5): 398-399. (in Chinese)
[7]	张云飞, 张倩, 韩玲, 等. 2006—2023年中国恙虫病流行病学特征分析[J]. 疾病监测, 2024, 39(12): 1629-1634.
	Zhang YF, Zhang Q, Han L, et al. Epidemiological study of scrub typhus in China, 2006-2023[J]. Dis Surveillance, 2024, 39(12): 1629-1634. (in Chinese)
[8]	Liu QY, Ji HQ, Shang M. Notified vector-borne diseases: China, 2005-2024[J]. China CDC Weekly, 2025, 7(29): 961-966.
[9]	周瑜, 杨晓庆, 明小力, 等. 恙虫病的疫情及防控现状[J]. 中国人兽共患病学报, 2023, 39(10): 1024-1031.
	Zhou Y, Yang XQ, Ming XL, et al. Epidemiological situation of scrub typhus, and current status of prevention and control[J]. Chin J Zoonoses, 2023, 39(10): 1024-1031. (in Chinese)
[10]	张嘉溪, 谭盛葵. 恙虫病流行病学研究新进展[J]. 中国热带医学, 2022, 22(3): 274-278.
	Zhang JX, Tan SK. New progress in epidemiology of scrub typhus[J]. China Trop Med, 2022, 22(3): 274-278. (in Chinese)
[11]	周瑜, 任天广. 云南省恙虫病媒介恙螨区系研究进展[J]. 中国热带医学, 2023, 23(5): 550-555.
	Zhou Y, Ren TG. Fauna of scrub typhus vector chigger mites in Yunnan Province[J]. China Trop Med, 2023, 23(5): 550-555. (in Chinese)
[12]	Peng PY, Xu L, Wang GX, et al. Epidemiological characteristics and spatiotemporal patterns of scrub typhus in Yunnan Province from 2006 to 2017[J]. Sci Rep, 2022, 12(1): 2985.
[13]	曹婧, 亚红祥, 袁庆虹, 等. 云南省2006—2014年恙虫病发病率的聚类分析[J]. 中国人兽共患病学报, 2015, 31(8): 714-716, 723.
	Cao J, Ya HX, Yuan QH, et al. Hierarchical cluster analysis on the incidences of scrub typhus in Yunnan Province, China, 2006-2014[J]. Chin J Zoonoses, 2015, 31(8): 714-716, 723. (in Chinese)
[14]	Kim HJ, Fay MP, Feuer EJ, et al. Permutation tests for joinpoint regression with applications to cancer rates[J]. Stat Med, 2000, 19(3): 335-351.
[15]	丁书姝, 郭浩阳, 陈浩, 等. 2004—2020年中国肝癌死亡率时间趋势分析[J]. 中华疾病控制杂志, 2023, 27(8): 963-967.
	Ding SS, Guo HY, Chen H, et al. Time trend analysis of liver cancer mortality in China from 2004 to 2020[J]. Chin J Dis Control Prev, 2023, 27(8): 963-967. (in Chinese)
[16]	陈琪薇, 马新颜, 张青剑, 等. 2015—2021年石家庄市0-14岁儿童伤害病例流行病学特征及变化趋势分析[J]. 中华疾病控制杂志, 2024, 28(4): 443-450.
	Chen QW, Ma XY, Zhang QJ, et al. Epidemiological characteristics and trend analysis of injured children aged 0-14 years in Shijiazhuang City, 2015-2021[J]. Chin J Dis Control Prev, 2024, 28(4): 443-450. (in Chinese)
[17]	刘珊山, 于晓辉, 秦建伟. 1990—2019年中国肝硬化疾病负担变化趋势分析[J]. 临床肝胆病杂志, 2024, 40(4): 726-733.
	Liu SS, Yu XH, Qin JW. Changing trend of the disease burden of liver cirrhosis in China from 1990 to 2019[J]. J Clin Hepatol, 2024, 40(4): 726-733. (in Chinese)
[18]	徐俊芳, 夏志贵, 周晓农, 等. 我国2004—2013年疟疾发病率的时间趋势分析[J]. 中国寄生虫学与寄生虫病杂志, 2017, 35(2): 114-119.
	Xu JF, Xia ZG, Zhou XN, et al. Time-series anaylsis of malaria incidence in China during 2004-2013[J]. Chin J Parasitol Parasit Dis, 2017, 35(2): 114-119. (in Chinese)
[19]	马星宇, 张振, 唐秀娟, 等. 深圳市2015—2021年学生流行性感冒流行特征及趋势分析[J]. 中国热带医学, 2022, 22(7): 634-639.
	Ma XY, Zhang Z, Tang XJ, et al. Epidemiological characteristics and trend analysis of influenza among students in Shenzhen, 2015-2021[J]. China Trop Med, 2022, 22(7): 634-639. (in Chinese)
[20]	Xiao D, Long Y, Wang SQ, et al. Epidemic distribution and variation of Plasmodium falciparum and Plasmodium vivax malaria in Hainan, China during 1995-2008[J]. Am J Trop Med Hyg, 2012, 87(4): 646-654.
[21]	李艳萍, 税铁军, 何恺, 等. 应用集中度和圆形分布法分析保山市恙虫病季节性特征[J]. 中国寄生虫学与寄生虫病杂志, 2025, 43(1): 147-151.
	Li YP, Shui TJ, He K, et al. Seasonal characteristics of scrub typhus in Baoshan City using concentration ratio and circular distribution methods[J]. Chin J Parasitol Parasit Dis, 2025, 43(1): 147-151. (in Chinese)
[22]	邓淑珍, 张丽芳, 沈秀莲, 等. 2014—2022年中缅边境临沧市恙虫病流行病学特征及时空聚集分析[J]. 华南预防医学, 2025, 51(1): 50-54.
	Deng SZ, Zhang LF, Shen XL, et al. Epidemiological characteristics and spatial and temporal aggregation of tsutsugamushi disease in Lincang city, China-Myanmar border region, 2014-2022[J]. South China J Prev Med, 2025, 51(1): 50-54. (in Chinese)
[23]	李卓. 2006—2023年云南省恙虫病时空特征及影响因素分析[D]. 吉林大学, 2025: 24-25.
	Li Z. Analysis on the spatiotemporal characteristics and influencing factors of scrub typhus in Yunnan Province from 2006 to 2023[D]. Jilin University, 2025: 24-25. (in Chinese)
[24]	邓淑珍, 董雪梅, 沈秀莲, 等. 云南省2013—2022年恙虫病的流行病学特征分析[J]. 中国媒介生物学及控制杂志, 2024, 35(2): 194-199.
	Deng SZ, Dong XM, Shen XL, et al. Epidemiological characteristics of scrub typhus in Yunnan Province, China, 2013-2022[J]. Chin J Vector Biol Control, 2024, 35(2): 194-199. (in Chinese)
[25]	刘如金, 郭宪国, 赵成富, 等. 云南省德宏傣族景颇族自治州小兽体表恙螨分类名录[J]. 中国媒介生物学及控制杂志, 2024, 35(3): 349-357.
	Liu RJ, Guo XG, Zhao CF, et al. Catalogue of chigger mites on small mammals in Dehong Dai and Jingpo Autonomous Prefecture of Yunnan Province along the China-Myanmar border[J]. Chin J Vector Biol Control, 2024, 35(3): 349-357. (in Chinese)
[26]	曾志伟, 祝寒松, 韩腾伟, 等. 福建省2014—2020年恙虫病流行特征和时空聚集性[J]. 中华疾病控制杂志, 2023, 27(7): 858-863.
	Zeng ZW, Zhu HS, Han TW, et al. Epidemiological characteristics and spatial-temporal clutering of scrub typhus in Fujian Province from 2014 to 2020[J]. Chin J Dis Control Prev, 2023, 27(7): 858-863. (in Chinese)
[27]	秦瑶, 张伦, 张瑶, 等. 2016—2020年四川省恙虫病流行特征分析[J]. 预防医学情报杂志, 2022, 38(10): 1329-1333.
	Qin Y, Zhang L, Zhang Y, et al. Epidemiological characteristics of scrub typhus in Sichuan Province from 2016 to 2020[J]. J Prev Med Inform, 2022, 38(10): 1329-1333. (in Chinese)
[28]	Han L, Zhang YF, Jin XJ, et al. Changing epidemiologic patterns of typhus group rickettsiosis and scrub typhus in China, 1950-2022[J]. Int J Infect Dis, 2024, 140: 52-61.
[29]	刘晨曦, 郭宪国, 吕艳, 等. 四川省凉山彝族自治州鼠类等小兽体表恙螨的调查研究[J]. 中国寄生虫学与寄生虫病杂志, 2025, 43(3): 385-394.
	Liu CX, Guo XG, Lv Y, et al. Investigation of chigger mites on the surface of murines and other small mammals in Liangshan Yi Autonomous Prefecture, Sichuan Province[J]. Chin J Parasitol Parasit Dis, 2025, 43(3): 385-394. (in Chinese)
[30]	李文, 牛彦麟, 赵哲, 等. 气象因素对云南省西南地区恙虫病流行的影响与滞后效应研究[J]. 中华流行病学杂志, 2021, 42(7): 1235-1239.
	Li W, Niu YL, Zhao Z, et al. Meteorological factors and related lag effects on scrub typhus in southwestern Yunnan[J]. Chin J Epidemiol, 2021, 42(7): 1235-1239. (in Chinese)
[31]	李波, 张美文, 周训军, 等. 我国农区鼠害现状与治理对策[J]. 中华卫生杀虫药械, 2025, 31(2): 117-121.
	Li B, Zhang MW, Zhou XJ, et al. The current status of rodent pest in agriculture and countermeasures for control in China[J]. Chin J Hyg Insectic Equip, 2025, 31(2): 117-121. (in Chinese)
[32]	李紫薇, 尹家祥. 鼠类与环境因素和人类活动的关系[J]. 中国媒介生物学及控制杂志, 2023, 34(1): 117-121.
	Li ZW, Yin JX. The relationship between rodents and environmental factors and human activities[J]. Chin J Vector Biol Control, 2023, 34(1): 117-121. (in Chinese)