[Quality analysis of malaria microscopic examinations in Jiangsu Province from 2011 to 2017]

To understand the quality of production of blood slides and laboratory personnel's ability to microscopically examine Plasmodium at Jiangsu Province clinic inspection stations at all levels, so as to provide the evidence for the construction of malaria diagnostic laboratories and the evaluation of malaria elimination effect.

After the reexamination of the negative blood slides of the examination stations of the malaria center in each county (district), the negative blood slides of the outpatient inspection station in the district and all the positive blood slides of the direct report of the network from 2011 to 2017, the staining and cleanliness of the blood smears, microscopic examination results and the coincidence rate of positive blood species were comprehensively analyzed.

A total of 19 109 checked blood samples were examined. The qualified rates of blood preparation, dyeing and cleanliness were 87.5%, 89.3% and 87.6%, respectively. The quality of reexamined blood slides in different years showed statistically significant difference (all P < 0.05), by using chi-square trend test, and there was a trend of increasing year by year. There was a significant difference in the quality of the reexamined blood slides among the different cities with districts (P < 0.05). In addition, there were 1 860 blood samples from 2012 to 2017, and the total coincidence rate was 87.4% and the coincidence rate of positive blood smear examinations was 98.9%. The species coincidence rates of Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, Plasmodium ovale and mixed infection were 95.4%, 33.3%, 56.0%, 76.5% and 9.1%, respectively (P < 0.05). The total coincidence rates of blood smear reexaminations in different years were 85.0%, 90.1%, 86.0%, 85.3%, 90.0% and 87.6% from 2012 to 2017, respectively, and the difference was not statistically significant (P > 0.05).

The quality of blood slides at the primary clinic inspection stations in Jiangsu Province conforms to the standard established by the provincial malaria reference laboratory; however, the ability of Plasmodium species identification is insufficient and needs to be improved.