Abstract: Objective To analyze the epidemiological characteristics of scrub typhus in Honghe Hani and Yi Autonomous Prefecture (Honghe Prefecture), Yunnan Province on the border of China and Vietnam, so as to provide a scientific basis for formulating scrub typhus control strategies in the future.Methods The information on cases of scrub typhus in Honghe Prefecture from 2013 to 2022 were collected from the China Information System for Disease Control and Prevention. The data were analyzed using descriptive epidemiological methods, the Chi-squared test, the rank sum test, and concentration distribution analysis.Results A total of 8 035 cases of scrub typhus were reported in Honghe Prefecture in the past 10 years, with an average annual incidence of 17.37/100 000, including 1 death. The reported incidence of scrub typhus showed an increasing trend over the years (χ²_trend=3 044.855, P<0.001). Yuanyang County reported the highest number of cases (1 888 cases, an incidence of 47.22/100 000), and Pingbian County reported the highest incidence (1 280 cases, an incidence of 82.53/100 000). The occurrence of scrub typhus had strong seasonality, with the peak period concentrated during June to September (5 854 cases, 72.86%). The cases of scrub typhus were mainly aged 30-<70 years (4 848 cases, 60.33%) and 0-<10 years (1 778 cases, 22.13%). The male-to-female ratio was 0.98:1. A majority of the cases were farmers among occupations (5 588 cases, 69.55%). The median time from disease onset to diagnosis was 10 days. The time from disease onset to diagnosis was statistically different between years (H=102.812, P=0.001) and between the northern and southern regions (bounded by the Tropic of Cancer) (H=1 087 686.000, P=0.025), with a shorter time interval in the southern region than in the northern region. The reported cases were mainly from general hospitals at the county (city) level or above, and 95.16% of them were clinically diagnosed cases.Conclusions The incidence of scrub typhus is on the rise in Honghe Prefecture, more frequent in children and middle-aged and elderly people in rural areas, with significant regional difference and significant seasonality with the peak in summer and autumn, and the time interval from onset to diagnosis is relatively long. It is necessary to strengthen scrub typhus surveillance and to reclassify it as a notifiable infectious disease to reduce the economic burden of the disease.

Key words: China-Vietnam border, Scrub typhus, Epidemiological characteristic, Concentration distribution

摘要： 目的 分析中越边境云南省红河哈尼族彝族自治州（红河州）恙虫病流行病学分布特征,为制定恙虫病防制策略提供科学依据。方法 从中国疾病预防控制信息系统中收集红河州2013－2022年恙虫病相关资料,采用描述性流行病学方法,利用χ²检验、秩和检验、集中度分布对数据进行统计分析。结果 红河州10年间共报告恙虫病8 035例,年均报告发病率为17.37/10万,死亡1例。报告发病率呈现逐年上升趋势（χ趋势2=3 044.855,P<0.001）,元阳县报告发病例数最多（1 888例,发病率为47.22/10万）,屏边县报告发病率最高（1 280例,发病率为82.53/10万）；恙虫病发病有较强的季节性,发病高峰集中在6－9月（5 854例,占72.86%）；以30～<70岁年龄组（4 848例,占60.33%）和0～<10岁年龄组（1 778例,占22.13%）为主；男女发病性别比为0.98∶1；职业以农民为主（5 588例,占69.55%）,发病至诊断时间中位数为10 d,不同年份发病至诊断时间差异有统计学意义（H=102.812,P=0.001）,南、北区（以北回归线为界）发病至诊断时间差异有统计学意义（H=1 087 686.000,P=0.025）,南区短于北区,报告病例主要来源于县（市）级及以上综合医院,以临床诊断病例为主,占95.16%。结论 红河州恙虫病发病呈上升趋势,农村中老年人群和儿童高发,发病地区差异明显,夏秋季流行,发病至诊断为恙虫病时间间隔较长,建议加强恙虫病监测并将其重新列为法定报告传染病,以降低其造成的疾病经济负担。

关键词: 中越边境, 恙虫病, 流行特征, 集中度分布