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Quality evaluation on the preparation of the malaria blood smears at the national level in 2019
Received date: 2022-01-18
Revised date: 2022-08-05
Online published: 2022-10-25
To understand and evaluate the quality of malaria blood smears in all provinces of China, provide data support for guiding the quality control of malaria microscopic examination during post-malaria elimination, and explore the standard model of evaluating the capability of preparing malaria blood smears. One blood smear of the first malaria case in a month in each province(direct-administered municipalities and autonomous regions) was collected, with a total of 5 cases or more in 2019. Provinces without malaria cases were provided with negative blood smears during malaria screening. Ten experts with WHO external assessment level 1 or level 2 certificates of malaria microscopy capability were organized to form two quality assessment teams. Fifteen assessment criteria (①-) were determined. All blood smears were divided into two groups for each province and sent to two teams of experts for double-blind reading evaluation. The single blood smear score and the qualified rate of blood smear in different provinces (15 points for each blood smear, 13 points for qualified) were calculated. The level of blood smear preparation in each province was graded (the qualification rate ≥ 90%, 80%-90%, 70%-80%, < 70% were A, B, C and D, respectively). The institutes that prepared the blood smears at different provinces were divided into provincial laboratories and non-provincial laboratories, and the differences of average single blood smear scores and preparation grades among different laboratories were compared. The average score rates of all blood smears were calculated and compared according to each evaluation standard. The average scores of blood smears between different laboratories were compared by t-test, and the levels of blood smears were compared by Person chi-square test or Fisher exact probability method. A total of 285 blood smears were collected from 28 provinces. The national average single blood smear score is (13.3 ± 1.5) with the highest score being 14.8 points, the lowest being 8.9 points, and the median being 13.6 points. The total rate of satisfied blood smears was 72.6% (207/285). The highest satisfaction rate in all provinces was 100%, and the lowest was 20%. The number of provinces categorized into A, B, C and D levels were 11, 3, 2 and 12, respectively. The average score in provincial laboratories was (14.2 ± 0.2), higher than that in non-provincial laboratories [(13.0 ± 0.4)] (t = 2.3, P < 0.05). Among the 15 provinces in which blood smears were prepared by non-provincial laboratories, 4 were marked as level A, 2 were marked as level B and 9 were marked as level D. Among the 9 provinces in which blood smears were prepared by provincial laboratories 6 were marked as level A, 1 was marked as level B, 1 was marked as level C, and 1 marked as level D. The level of preparing blood smears in the provincial laboratories was higher than that in the non-provincial laboratories (Fisher exact probability method, P < 0.05). The coefficient of variation of the average single blood smear score among different provinces (municipalities, autonomous regions) was 11.2%, and the coefficient of variation of the qualification rate was 37.5%. Nationally, the scoring rate of blood smear in items ②, ③, ⑧, ⑨, and of the evaluation criteria is low (74.8%-85.3%), which was mainly due to the unsatisfied thick blood smears. The main deducted points in provincial laboratories marked as level C are and, which mainly show that there are many contaminants in the blood smears after staining, and the staining is poor. The deducted points in the provincial laboratory marked as level D were ⑩, and. The main reason is that no red blood cells are observed in the thin films, and the protozoal morphology has changed. The levels of preparing blood smears varied in different provinces. The levels of preparing blood smears in provincial laboratories were higher than those in non-provincial laboratories. Normalized operation in preparing blood smears in basic units should be strengthened.
Key words: Malaria; Rate of qualified blood smear; Blood smear; Quality control
LI Mei , ZHOU He-jun , XIA Zhi-gui , ZHANG Li , TU Hong , YIN Jian-hai . Quality evaluation on the preparation of the malaria blood smears at the national level in 2019[J]. CHINESE JOURNAL OF PARASITOLOGY AND PARASITIC DISEASES, 2022 , 40(6) : 754 -759 . DOI: 10.12140/j.issn.1000-7423.2022.06.010
| [1] | World Health Organization. From 30 million cases to zero: China is certified malaria-free by WHO[EB/OL]. (2021-06-30). [2022-01-07]. https://www.who.int/news/item/30-06-2021-from-30-million-cases-to-zero-china-is-certified-malaria-free-by-who. |
| [2] | World Health Organization. World malaria report 2021: regional data and trends[R]. Geneva: WHO, 2022. |
| [3] | Zhang Li, Tu H, Zhou SS, et al. Malaria deaths: China, 2011—2020[J]. China CDC WKLY, 2021, 3 (17): 360-365. |
| [4] | National Health Commission and Family Plan of the People’s Republic of China. Microscopic examination of blood films for malaria parasites: WS/T 569—2017[S]. Beijing: Standards Press of China, 2017: 1-13. (in Chinese) |
| (中华人民共和国国家卫生和计划生育委员会. 疟原虫检测血涂片镜检法: WS/T 569—2017[S]. 北京: 中国标准出版社, 2017: 1-13.) | |
| [5] | National Health Commission and Family Plan of the People’s Republic of China. Diagnosis of malaria: WS/T 256—2015[S]. Beijing: Standards Press of China, 2015: 1-14. (in Chinese) |
| (中华人民共和国国家卫生和计划生育委员会. 疟疾的诊断: WS/T 256—2015[S]. 北京: 中国标准出版社, 2015: 1-14.) | |
| [6] | World Health Organization.Basic malaria microscopy Part Ⅰ. Learner’s guide[M]. Geneva: WHO, 2010: 46. |
| [7] | Samuel O, Sowemimo-Coker. Red blood cell hemolysis during processing[J]. Transfus Med Rev, 2002, 16(1): 46-60. |
| [8] | Zhang SS, Xia ZG, Yin JH, et al. Analysis report of the national technique competition for diagnosis of parasitic diseases in 2012:Ⅰ. Capability analysis of Plasmodium detection[J]. Chin J Parasitol Parasit Dis, 2013, 31(2): 131-134. (in Chinese) |
| (张少森, 夏志贵, 尹建海, 等. 2012年全国寄生虫病防治技术竞赛成绩分析报告: Ⅰ. 疟原虫检测能力考评结果分析[J]. 中国寄生虫学与寄生虫病杂志, 2013, 31(2): 131-134.) | |
| [9] | Ruan Y, Wang LY, Zhu TJ, et al. Analysis of results of assessment on national parasitic disease control and prevention techniques in 2015[J]. Chin J Schisto Control, 2017, 29(2): 155-158. (in Chinese) |
| (阮瑶, 王立英, 诸廷俊, 等. 2015年全国寄生虫病防治专业技术能力考核结果分析[J]. 中国血吸虫病防治杂志, 2017, 29(2): 155-158.) | |
| [10] | Cao YY, Zhu GD, Liu YB, et al. Analysis of the results of parasitic disease control skills contest in Jiangsu Province in 2018[J]. Chin J Parasitol Parasit Dis, 2020, 38(6): 731-736. (in Chinese) |
| (曹园园, 朱国鼎, 刘耀宝, 等. 2018年江苏省寄生虫病防治技能竞赛成绩分析[J]. 中国寄生虫学与寄生虫病杂志, 2020, 38(6): 731-736.) |
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