A report of the last indigenous malaria case in Yunnan

Abstract

This report aims to provide sufficient and strong evidence for achieving the goal of malaria elimination in Yunnan province through elaboration of diagnosis, treatment, epidemiological investigation, focus disposal and subsequently tracking survey on a P.vivax malaria case. This case was directly reported by the Center for Disease Control and Prevention of Yingjiang County, Dehong Prefecture, Yunnan Province on April 17, 2016 through the China Information System for Diseases Control and Prevention, and then was determined as the last indigenous malaria case in Yunnan Province. The patient Wang, male, 3 years old, scattered children, living in Longpan Yi She, Longpan Village, Taiping Town, Yingjiang County, Dehong Prefecture, Yunnan Province. His father is a farmer and mother is a local village doctor. The parents said the baby has never lived in Myanmar or other areas with high malaria epidemic in their county or province since birth. Due to chills, fever and sweating for 5 days, he went to Yingjiang County Center for Disease Control and Prevention on April 15, 2016. The rapid diagnostic reagent for Plasmodium antigen (RDT) was positive, and P. vivax was detected by blood smear microscopy, which was confirmed as vivax malaria by microscopic examination in Yingjiang County and Dehong Prefecture. The case was determined as an indigenous malaria case through laboratory confirmation at county, prefecture and provincial levels, case and vector investigation of the focus. Eight times active case investigations were implemented for longitudinal tracking after the disposal of the epidemic site with a total of 588 person-times received blood tests were conducted, and no positive results were found from April 18, 2016 to December 31, 2019. Twice vector surveys were carried out in June-September 2016, and no malaria vector was caught as well. The information of epidemiological investigation and laboratory test results on 1 032 self-reported cases from Yunnan province and 7 cases of registered residences in Yunnan reported by other provinces in China were reviewed. All cases were excluded from local infection. During the same period above, 6 105 times of monitoring and evaluation for malaria elimination at all levels were implemented in Yunnan, no casereported were found omitted, concealed or misdiagnosis, meanwhile, 5 251 negative blood slides were received regular sampling inspection, with a negative compliance rate of 100%. Based on the comprehensive analysis, according to the classification criteria of malaria case and focus in China′s Action Plan for Malaria Elimination (2010-2020) and the Technical Scheme of Malaria Elimination, the case was finally determined to be the last indigenous case of P. vivax malaria in Yunnan province. The determination of the last indigenous malaria case in Yunnan province is not only accurate but also well founded. Ultimately, this case was confirmed and approved to be the last indigenous malaria case in China by the national expert panel of malaria elimination at a seminar on last indigenous malaria case of China held in Kunming, Yunnan, China in October, 2019.

Abstract

摘要： 报道 2016 年 4 月 17 日由云南省德宏州盈江县疾病预防控制中心通过国家疾病监测信息报告管理系统网络 直报, 并被确定为云南省最后一例本地感染间日疟病例的诊断、治疗、流行病学调查、疫点处置及后续追踪等相关情 况, 为云南省到达消除疟疾目标提供充分有力的证据。患者王某某, 男, 3 岁, 散居儿童, 居住在云南省德宏州盈江县太 平镇龙盆村龙盆一社。父亲是农民, 母亲是当地村医, 父母表示患儿从出生至今无到过缅甸或本省、本县其他高疟区 的流动居住史。因发冷、发热、出汗 5 d, 于 2016 年 4 月 15 日到盈江县疾控中心就诊, 疟原虫抗原快速诊断试剂 (RDT) 检测阳性, 血涂片镜检检出单纯间日疟原虫, 经盈江县和德宏州两级镜检复核确认为间日疟。后省级疟疾诊断参比实 验室镜检和疟原虫核酸 (PCR) 复核确认为间日疟。在 2016 年 4 月 18 日—2019 年 12 月 31 日, 在疫点处置后开展 8 次主 动病例侦查进行纵向追踪, 共血检 588 人次, 未发现阳性。2016 年 6—9 月开展 2 次媒介调查, 未捕获传疟媒介。同时对 全省报告的 1 032 例和外省报告的 7 例云南籍病例的流行病学个案调查资料及实验室检测结果进行审查和复核, 均排 除本地感染, 对全省开展的 6 105 次各级的消除疟疾工作督导检查, 均未发现病例的漏报、瞒报和漏诊现象, 抽检复核 5 251 张阴性血片, 阴性符合率 100%。根据《中国消除疟疾行动计划 (2010—2020) 》和《消除疟疾技术方案》病例和疫点 分类标准, 最终判定该病例为云南省最后一例本地感染间日疟病例。2019 年 10 月, 国家消除疟疾专家组在云南省昆明 市召开全国最后一例本地感染疟疾病例研讨会, 确认该病例为中国最后一例本地感染疟疾病例。