Abstract: Objective　To analyze the epidemiological characteristics of reported imported malaria cases in Zhengzhou City from 2016 to 2020, so as to provide insights into the management of imported malaria in the city. Methods　All data pertaining to cases with definitive diagnosis of malaria in Zhengzhou City from 2016 to 2020 were captured from the National Notifiable Disease Report System and the Information Management System for Parasitic Disease Control in China, including individual demographic data, and malaria onset, initial diagnosis and definitive diagnosis data. All data were descriptively analyzed. The duration from malaria onset to initial diagnosis, from initial diagnosis to definitive diagnosis and from onset to definitive diagnosis was compared among cases. In addition, the diagnoses of imported malaria cases in which definitive diagnosis was made were compared with the reexaminations by Zhengzhou Municipal Malaria Diagnosis Reference Laboratory. Results　A total of 302 cases with definitive diagnosis of malaria were reported in Zhengzhou City from 2016 to 2020, and all were imported cases, with Plasmodium falciparum malaria as the predominant type (230 cases, 76.2%). There were 293 malaria cases imported from Africa (293 cases, 97.0%), which mainly included Nigeria (48 cases, 15.9%), Angola (40 cases, 13.2%), and the Democratic Republic of the Congo (29 cases, 9.6%). There was no obvious seasonality found in the date of malaria onset and time of reporting malaria. The ratio of male to female malaria cases was 49.3∶1, and there were 103 cases (34.1%) with the current residency address in Zhengzhou City, 193 cases (63.9%) with the current residency address in other cities of Henan Province and 6 cases (2.0%) in other provinces of China. There were 271 cases (89.7%) seeking initial diagnosis in medical institutions, and the diagnostic accuracy of malaria was 56.6% (171/302) at initial diagnosis institutions. A total of 122 cases (40.4%) sought medical care on the day of malaria onset, and 252 cases (86.4%) within 3 days; however, only 22 cases (7.3%) were definitively diagnosed on the day of onset, and 162 cases (53.6%) diagnosed within 3 days. There were no significant differences between malaria cases seeking initial diagnosis at medical institutions and disease control and prevention institutions in terms of the duration from malaria onset to initial diagnosis (Z = −1.663, P > 0.05), from initial diagnosis to definitive diagnosis (Z = −0.413, P > 0.05) or from malaria onset to definitive diagnosis (Z = −0.838, P > 0.05). The median duration (interquartile range) from initial diagnosis to definitive diagnosis of malaria was 3.00 (2.00), 3.00 (6.00), 2.00 (4.00) d and 1.00 (1.00) d among cases seeking medical care at township⁃level and lower, county⁃, city⁃ and province⁃level medical institutions, and the median duration from initial diagnosis to definitive diagnosis of malaria was significantly longer among cases seeking medical care at township⁃level and lower medical institutions than at city⁃ (Z = −3.286, P < 0.008 33) and province⁃level medical institutions (Z = −9.119, P < 0.008 33), while the median duration from initial diagnosis to definitive diagnosis [1.00 (3.00) d vs. 2.00 (4.00) d; Z = −4.099, P < 0.016] and from malaria onset to definitive diagnosis [3.00 (4.00) d vs. 4.00 (5.00) d; Z = −2.868, P < 0.016] among malaria cases with the current residency address in Zhengzhou City was both shorter than in other cities of Henan Province. The diagnostic accuracy was 89.1% (269/302) among malaria cases in which definitive diagnosis was made, and the accuracy of malaria reexaminations was 94.0% (284/302) in Zhengzhou Municipal Malaria Diagnosis Reference Laboratory. Conclusions　P. falciparum malaria was predominant among reported imported malaria cases in Zhengzhou City from 2016 to 2020, and these imported malaria cases were predominantly diagnosed at medical institutions; however, the diagnostic capability of malaria is poor in township⁃level and lower medical institutions. Strengthening the collaboration between medical institutions and disease control and prevention institutions and improving the diagnostic capability building at medical institutions are recommended to consolidate malaria elimination achivements.

Key words: Malaria, Imported case, Epidemiological characteristic, Zhengzhou City

摘要： 目的　分析2016—2020年河南省郑州市报告输入性疟疾确诊病例的流行病学特征，为进一步做好输入性疟疾防控工作提供依据。方法　在传染病报告信息管理系统和寄生虫病防治信息管理系统中，收集2016—2020年郑州市报告的疟疾确诊病例个案信息以及发病、初诊、确诊等诊断信息进行描述性流行病学分析；对不同特征疟疾病例从发病到初诊、从初诊到确诊及从发病到确诊时间进行比较分析，并对病例确诊单位诊断结果和市级疟疾诊断参比实验室复核结果的正确率进行分析。结果　2016—2020年郑州市累计报告疟疾确诊病例302例，均为输入性病例，以恶性疟（230例，占76.2%）为主。293例（占97.0%）病例自非洲输入，主要来源国为尼日利亚（48例，占15.9%）、安哥拉（40例，占13.2%）、刚果民主共和国（29例，占9.6%）。病例发病时间、报告时间均无明显季节性，病例男女性别比为49.3∶1，现住址为郑州市辖区、河南省其他设区市以及外省的病例数分别为103（占34.1%）、193（占63.9%）、6例（占2.0%）。初诊机构疟疾诊断阳性率为56.6%（171/302），89.7%（271例）为医疗机构初诊；发病当天就诊122例（占40.4%），3 d内就诊252例（占86.4%）；发病当天确诊22例（占7.3%），3 d内确诊162例（占53.6%）。至医疗机构和疾病预防控制（疾控）机构初诊的病例从发病至初诊、从初诊至确诊及从发病至确诊时间差异均无统计学意义（Z = –1.663、-0.413、-0.838，P均> 0.05）。在县级以下、县级、地市级和省级医疗机构初诊的病例从初诊至确诊中位时间（四分位间距）[M(QR)]分别为3.00（2.00）、3.00（6.00）、2.00（4.00）、1.00（1.00） d， 在县级以下医疗机构初诊者从初诊至确诊时间较地市级和省级医疗机构长（Z = –3.286、-9.119，P均< 0.008 33），在县级和地市级医疗机构初诊者从初诊至确诊时间较省级机构长（Z = –4.911、-4.303，P均< 0.008 33）。现住址为郑州市的病例从初诊至确诊时间[1.00（3.00） d]和从发病至确诊时间[3.00（4.00） d]均短于现住址为河南省其他设区市的病例[2.00（4.00）、4.00（5.00） d]（Z = –4.099、-2.868，P均< 0.016）。病例确诊单位疟疾诊断正确率为89.1%（269/302），市级疟疾诊断参比实验室复核结果正确率为94.0%（284/302）。结论　2016—2020年郑州市报告的输入性疟疾病例以恶性疟为主，病例诊断单位以医疗机构为主，县级以下医疗机构疟疾诊断能力较差。今后应积极开展医防合作、加强医疗机构疟疾诊断能力建设，以巩固消除疟疾成果。

关键词: 疟疾, 输入性病例, 流行病学特征, 郑州市