目的 通过实验室检测结果综合分析输入性疟疾病例样品的误判原因，为减少误判发生提供参考。 方法 收集2020—2021年各区疾控中心上报的输入性疟疾病例样品共112份[含血涂片、抗凝血、区疾控中心提取的疟原虫DNA（为区疾控组DNA）等]，由市级疟疾诊断参比实验室进行复核，分别进行显微镜检查、提取疟原虫基因组DNA（为市疾控组DNA）和多重PCR法检测。对其中镜检为阳性且区疾控中心报告荧光定量PCR（qPCR）结果为阴性的病例样品，分别加做qPCR检测，绘制扩增曲线，测量循环阈值（Ct），比较两组DNA的浓度和纯度。 结果 区疾控中心上报镜检样品112份，其中110份进行核酸检测；108份为疟原虫阳性样品，4份为阴性样品。经市疾控中心复核，镜检结果一致率为93.8%（105/112），其中阳性一致率为94.1%（96/102），阴性一致率为9/10；共筛选出7份输入性疟疾病例误判，其中定性错误3份（2份恶性疟误判为阴性，1份阴性误判为恶性疟），定种错误4份（1份三日疟误判为卵形疟，1份三日疟无法分型，2份卵形疟误判为间日疟）。经市疾控中心复核，核酸检测一致率为96.4%（106/110），其中阳性一致率为96.2%（102/106），阴性一致率为4/4。7例误判病例的区疾控组DNA多重PCR未扩增，市疾控组正常扩增；市、区疾控组DNA在qPCR检测中均正常扩增，市疾控组DNA对应样品的Ct值更低，扩增曲线更早进入指数增长期。区疾控组DNA浓度均大于市疾控组，而市疾控组DNA纯度更高。 结论 相关区疾控中心需提高疟原虫镜检能力，并选择合适的DNA提取试剂盒和qPCR试剂盒用于疟原虫核酸检测。

Objective Comprehensive analysis of laboratory test results of the samples from imported malaria cases to determine the causes of misdiagnosis, to provide reference for reducing the occurrence of misdiagnosis. Methods A total of 112 samples of imported malaria cases reported by each district centers for disease control and prevention (CDCs) from 2020 to 2021 were collected, including blood smears, anticoagulated blood, and Plasmodium genomic DNA extracted by district CDCs (district CDC group). The samples were rechecked by the municipal malaria reference laboratories through microscopic examination, genomic DNA extraction (municipal CDC group) and multiplex PCR assay, respectively. Among the samples of microscopic positives, where as real time quantitative PCR (qPCR) negatives reported by the district CDC, additional qPCR was conducted to plot amplification curves, determine the cycle threshold (Ct) values and compare the concentration and purity of DNA between the two groups. Results Microscopic examination was performed for 112 samples and nuclear acid detection were performed for 110 samples by the district CDCs. 108 were positive samples of Plasmodium and 4 were negative samples. The microscopic concordance rate was 93.8% (105/112), as reviewed by the municipal CDC. Among them, the positive concordance rate was 94.1% (96/102) and the negative concordance rate was 9/10. A total of seven imported malaria cases were screened for misdiagnosis. Three samples had qualitative identification mistakes by the district CDCs (two P. falciparum cases were misdiagnosed as negative, and one negative case was misdiagnosed as P. falciparum). Four samples have species identification mistakes, one sample was P. malariae misdiagnosed as P. ovale, one sample was P. malariae misdiagnosed as undefined, and two samples were P. ovale misdiagnosed as P. vivax. The concordance rate of nucleic acid detection was 96.4% (106/110), as reviewed by the municipal CDC, with a positive concordance rate of 96.2% (102/106) and a negative concordance rate of 4/4. In seven misdiagnosed cases, there were no amplifications of multiplex PCR the district CDC group, and normal amplifications in the municipal CDC group. The qPCR detections were amplified normally in both district and municipal CDC groups, and the corresponding samples in the municipal CDC group had lower Ct values and the amplification curve entered the exponential growth phase earlier. The DNA concentrations in the district CDC group were all greater than those in municipal CDC group, while municipal CDC group had higher DNA purity. Conclusion Relevant district CDCs need to improve their microscopic examination capability for Plasmodium, and use appropriate DNA extraction kits and qPCR kits for Plasmodium nucleic acid detection.