[Quality of blood smear examinations for malaria parasites in Chenzhou City after malaria elimination].

To analyze the quality of blood smear examinations for malaria parasites in Chenzhou City, so as to provide insights into sustainable consolidation of malaria elimination achievements.All positive blood smears from fever patients were irregularly sampled from each county (district) of Chenzhou City from 2018 to 2022 and reexamined, and no less than 3% negative blood smears were reexamined. The preparation, dyeing, cleanliness and microscopic examination results of blood smear were reexamined, and the quality of blood smear reexaminations was assessed using a descriptive statistical method.A total of 13 625 fever patients received blood smear examinations for malaria parasites in Chenzhou City from 2018 to 2022, of which 21 were positive and 13 604 were negative; 687 blood samples were reviewed, and the percentage of negative blood smear reexaminations was 4.90% (666/13 604), with a 63.51% rate of qualified negative blood smears preparation, a 67.87% rate of qualified dyeing and a 76.13% rate of qualified cleanliness, and no missing diagnosis found. There were 21 positive blood smears reexamined, and the proportions of qualified blood smears preparation, dyeing and cleanliness were all 85.71%, with 2 smears mistaking Plasmodium species (9.52%). The percentage of qualified negative blood smears preparation was 51.41% in 2022, which reduced by 31.61% in relative to that (75.17%) in 2019 (χ2 = 9.033, P < 0.05), and the percentage of qualified negative blood smears dyeing was 60.19% in 2022, which reduced by 28.82% in relative to that (84.56%) in 2019 (χ2 = 19.498, P < 0.05), while the percentage of qualified negative blood smears cleanliness was 62.96% in 2022, which reduced by 28.93% in relative to that (88.59%) in 2019 (χ2 = 23.826, P < 0.001). In addition, there were no significant differences in the proportion of qualified negative blood smears preparation (χ2 = 0.260, P > 0.05) or dyeing (χ2 = 1.094, P > 0.05) among the three years, while a significant difference was detected in the percentage of qualified negative blood smears cleanliness (χ2 = 12.175, P < 0.05).No missing diagnosis was seen in blood smear examinations for malaria parasites among fever patients in Chenzhou City after malaria elimination; however, there were reductions in proportions of qualified blood smears preparation, dyeing and cleanliness. Quality control of blood smear examinations is recommended to be reinforced in key regions of Chenzhou City.［摘要］目的 分析郴州市消除疟疾后疟原虫血片质量, 为持续巩固消除疟疾成果提供科学依据。方法 2018—2022 年, 不定期抽取郴州市各县 (市、区) 发热病人疟原虫血片, 阳性血片全部进行复核、阴性血片抽检数量不少于总数的 3%。对血片制作、染色、清洁度及镜检结果进行复核, 采用描述性统计方法对血片质量复核结果进行分析。结果 2018—2022 年, 郴州市累计开展发热患者疟原虫血检 13 625人, 其中检出疟原虫阳性 21 人、阴性 13 604 人。共复核血片 687 张, 阳性血片 21 张、阴性血片 666 张, 阴性血片复核率 4.90% (666/13 604), 阴性血片制作合格率为 63.51%、染色合格率为 67.87%、清洁度合格率为 76.13%, 未发现漏检; 复核所有阳性血片 21 张, 制作合格率、染色合格率和清洁度合格率均为 85.71%, 发现分型错误血片 2 张 (9.52%)。2022 年阴性血片制作合格率为 51.41%, 较 2019 年显著下降 (χ2 = 9.033, P < 0.05); 2022年阴性血片染色合格率为 60.19%, 较 2019 年显著下降 (χ2 = 19.498, P < 0.001); 2022 年阴性血片清洁度合格 率为 62.96%, 较2019年显著下降 (χ2 = 23.826, P < 0.001)。2020—2022 年阴性血片制作合格率 (χ2 = 0.260, P > 0.05)、染 色合格率 (χ2 = 1.094, P > 0.05) 差异均无统计学意义, 但清洁度合格率差异有统计学意义 (χ2 = 12.175, P < 0.05)。结论 疟疾消除后, 郴州市发热患者疟原虫血检未出现漏检现象, 血片制作、染色和清洁度合格率有所下降, 应加强重点地区 血片质量控制。.