Epidemic situation and discussion on countermeasures of imported malaria in He'nan, 2016-2019

Objective To analyze the epidemiological characteristics of imported malaria in He´nan Province during the late stage of malaria elimination from 2016 to 2019, so as to provide the evidence based technical and theoretical support for strategies and measures in the post elimination stage. Methods The malaria epidemic data and related case reporting information in He´nan Province from 2016 to 2019 were collected. The epidemic situation, distribution characteristics of cases, source of infection, diagnosis and treatment management and recurrence of vivax malaria cases were analyzed by descriptive epidemiology. Results A total of 769 malaria cases were reported in He´nan Province from 2016 to 2019, all imported from abroad. Among them, 581 cases were falciparum malaria, 107 cases were ovale malaria, 49 cases were vivax malaria, 24 cases were malariae malaria, 1 case was knowlesi malaria, and 7 cases were mixed infection. The imported cases came from 41 countries in three continents, and Africa had the largest number of imported cases (738 cases), accounting for 95.97% of the total number of imported cases. The cases were distributed in 18 provincial cities, involving 149 counties (cities and districts), and showed sporadic distribution. The majority of the patients were male (755 cases, accounting for 98.18%), mainly concentrated in the age group of 30-50 years (496 cases, accounting for 64.50%), and the majority were foreign migrant workers (588 cases, accounting for 76.46%). All cases were reported all year round, without obvious seasonal characteristics. The average time from onset to initial diagnosis, and from initial diagnosis to diagnosis was 2.6 days and 2.7 days respectively. The report rate of 24 hours after diagnosis was 100%, the epidemiological investigation rate within 3 days was 98.18%, and the disposal rate of epidemic spot within 7 days was 96.49%. From 2016 to 2019, 7 P. vivax cases relapsed within 1 year, and 2 of them had a third attack. Conclusion During 2016-2019, there was no local infection in He´nan Province, but the epidemic of imported malaria is still serious. Therefore, the risk of secondary infection and epidemic spread caused by imported malaria can not be ignored. All localities should continue to do a good job in monitoring after the elimination of malaria and adopt targeted measures to prevent re-transmission of malaria and consolidate the achievements of malaria elimination. 摘要:目的 分析2016—2019年河南省输人性疟疾流行病学特征,为消除后阶段的策略和措施提供数据支撑和 理论依据。 方法 收集2016—2019年河南省疟疾疫情数据及相关的病例资料,对疫情概况、病例的分布特征、感染来 源、诊治管理情况及间日疟病例复发情况等进行统计分析。 结果 2016—2019年河南省共报告疟疾病例769例,均由 境外输人。其中恶性疟581例,卵形疟107例,间日疟49例,三日疟24例,诺氏疟1例,混合感染7例。输人病例来源于 3大洲的41个国家,非洲输人最多(738例）,占输人病例总数的95.97%,病例的分布遍及18个省辖市,涉及149个县 (市、区）,并呈散发分布。发病人群男性居多(755例,占98.18%),主要集中在30~50岁年龄段(496例,占64.50%),以 境外务工人员为主(588例,占76.46%)。全年均有病例报告,无明显的季节特征。病例从发病到初诊、从初诊到确诊的 平均时间分别为2.6 d和2.7 d;诊断后24 h报告率为100%,3 d内完成流行病学调査率为98.18%,7 d内疫点处置率为 96.49%。2016—2019年,7例间日疟病例出现复发,复发时间均小于1年,其中2例病例出现二次复发。 结论 2016—2019年,河南省维持无本地感染病例状态,输人疫情形势依旧严峻,输人性疟疾引起继发感染和疫情扩散的风险不容 忽视。建议各地坚持不懈做好消除疟疾后的监测工作,精准施策,防止输人再传播,巩固消除疟疾成果。