Epidemiological characteristics of overseas imported malaria in Chongqing, 2016-2019

Objective Through analyzing the epidemiological characteristics and case management of imported malaria in Chongqing, to discover the weakness of malaria control program, and we provide technical advice for the adjustment of malaria prevention and control strategies. Methods Malaria cases information reported in Chongqing were collected from National Parasitic Diseases Information Management System on January 1, 2016 – December 31, 2019. Descriptive statistical analysis was used to study the distribution characteristics of cases in time, spaces and crowds. The interval days from "case onset" to "cases been diagnosed" were compared according to the annual and illness degree. Results There were a total of 131 imported malaria cases reported in Chongqing from 1 Jan 2016 to 31 Dec 2019, including 102 falciparum malaria, 16 vivax malaria, 10 ovale malaria, 2 mixed infection, and 1 quartan malaria. Most of the cases were male construction workers infected in Africa. There were 28 counties (districts) reported cases, among them, 30 cases were reported in Yuzhong District, 27 in Shapingba District, and each 9 cases were reported in Wanzhou District and Yubei District. of which 4 districts reported 57.30% of the total. County level medical institutions was the first choice for 37.40% of the cases when they began feeling sick, and the proportion of cases got malaria diagnosis in county level medical institutions was 63.27% (31/49). The average interval days of the cases from "malaria onset" to "first visit to the hospital" was 3.81 days (median= 1 days), and from "first visit to the hospital" to "got malaria diagnosed" was 4.65 days (median=2 days). The proportion of hospitalized cases was 58.02%. The interval days of hospitalized cases from "first visit to the hospital" to "got malaria diagnosed" was significantly longer than the interval days of general cases ( P <0.01). Conclusion The malaria cases in Chonqing were mostly imported from Africa, of which the interval days from from "malaria onset" to "got malaria diagnosed" was long within a high proportion of hospitalized cases. The efficient measures to reduce the incidence of severe malaria and mortality were: to strengthen malaria health education among the oversea workers, carry out technical training courses on malaria diagnosis and treatment at the primary medical institutions, and establish one specialized malaria medical treatment hospital in each county in Chongqing. 摘要:目的 分析重庆市 2016—2019 年输人性疟疾疫情的流行病学特征和病例管理情况, 评估重庆市疟疾的防 控工作薄弱环节, 为重庆市消除疟疾防控措施的调整提供依据。 方法 从国家寄生虫病信息管理系统收集 2016 年 1 月 1 日一 2019 年 12 月 31 日重庆市辖区内报告的疟疾病例个案信息, 对病例在时间、空间、人群的分布进行描述性统计 分析, 对病例在发病到初诊和初诊到确诊的间隔时间按年度和病情程度进行比较。 结果 共报告确诊境外输人疟疾 131 例, 其中恶性疟 102 例, 间日疟 16 例, 卵形疟 10 例, 混合感染 2 例, 三日疟 1 例。病例以在非洲地区务工的青壮年男 性为主。有 28 个区县有病例报告, 其中渝中区 30 例, 沙坪坝区 27 例, 万州区和渝北区均报告 9 例, 4 个区县报告病例数 占全部病例的 57.3%。病例初次诊单位主要在县级医疗机构占 37.4%, 其诊断正确率为 63.3%(31/49)。病例从“发病-初诊”和“初诊-确诊”间隔时间的中位数分别为 1 d 和 2d。症状较重住院治疗病例占 58.0%。住院治疗病例从“初诊-确诊”间隔时间高于门诊治疗病例, 差异有统计学意义( P <0.01)。 结论 重庆市疟疾疫情以非洲输人恶性疟为主, 病例 从发病到确诊用时较长, 症状较重住院治疗的病例占比较高, 应加强对境外务工人员的疟疾防治知识培训, 开展基层 医疗卫生机构疟疾诊疗技术培训, 设立疟疾定点医疗救治机构减少疟疾重症和死亡病例发生。