A review of malaria elimination in Minhang District, Shanghai

Objective To analyze the malaria epidemic situation and prevention and control process, and we summarize and assess the malaria elimination work in Minhang District, Shanghai, so as to provide the evidence for maintaining the eradication of malaria. Methods The data of control work, reports, documents, work plans, strategies and measures of malaria in Minhang District from 1950 to 2019 were collected and analyzed, to indicate its epidemiological characteristics and preventive procedure by descriptive epidemiological methods. And we summarized and evaluated the process of eliminating malaria in Minhang District. Results Malaria used to be the most dangerous infectious disease in Minhang District. Two outbreaks occurred in 1954 and 1961 respectively, with the highest annual incidence of 7 824.98/100 000, with P. vivax as the dominant vector and Anopheles sinensis as the only vector. Through comprehensive prevention and control, the incidence of malaria gradually decreased to 10 per 100 000 in 1980, and the standard of basically eliminating malaria was met in 1985. In 2010, Minhang District launched the Action Plan for Eliminating Malaria, and implemented comprehensive technical measures focusing on eliminating the source of infection and blocking transmission. By 2015, there had been no local infection cases for five consecutive years, meeting the assessment standards for eliminating malaria. The malaria eradication maintenance phase began after 2016. According to the characteristics of malaria epidemic in different periods, Minhang District adopted targeted prevention and control measures, which experienced different stages of malaria epidemic, control, monitoring, elimination and post-elimination maintenance. After 2013, all the cases were imported from abroad, and the majority of them were middle-aged and young migrating population. There were no obvious characteristics of the infected species and onset time of the cases. The focus of prevention and control is to timely detect and deal with malaria cases to prevent further transmission. Conclusion Maintaining surveillance networks and surveillance capabilities, and preventing the risk of retransmission of imported cases has become a new challenge after malaria eradication has been entered the maintenance phase. 摘要：目的 分析上海市闵行区不同时期疟疾流行状况和防治历程, 总结闵行区消除疟疾工作, 为维持消除疟疾 状态提供依据。 方法 收集闵行区1950—2019年疟疾防治疫情相关报表、工作计划总结、防治文件和策略等资料, 采 用描述流行病学方法分析闵行区疟疾流行特征与防治措施, 总结评估闵行区消除疟疾历程。 结果 疟疾曾是闵行区 危害最大的传染病, 1954年和1961年先后发生过2次暴发流行, 年发病率最髙达7 824.98/10万, 以间日疟为主, 中华按 蚊为唯一传播媒介。经过综合防治, 1980年疟疾发病率逐步降低至10/10万, 1985年达到了基本消灭疟疾的标准;2010 年启动闵行区消除疟疾行动计划 , 实施以清除传染源、阻断传播为重点的综合技术措施 , 至2015年连续5年无本地感 染病例, 达到了消除疟疾考核标准;2016年后进人消除疟疾维持阶段。闵行区根据不同时期疟疾流行特点采取了针对 性防控措施, 经历疟疾流行、控制、监测、消除和消除后维持的不同阶段。2013年后病例均为境外输人性病例, 以中青 年流动人口为主, 感染虫种和病例发病时间无明显特征, 防控重点是及时发现和处置疟疾病例, 防止引起续发传播。 结论 达到消除疟疾标准后, 维持疟疾监测网络和监测能力, 防止输人性病例再传播风险成为面临的新挑战。