[Quality of malaria blood smears from fever patients in Zibo City, Shandong Province from 2011 to 2018].

Objective: To analyze the quality of malaria blood smears from fever patients in Zibo City from 2011 to 2018, so as to provide the scientific evidence for the development of the malaria post-elimination surveillance strategy.

Methods: All negative malaria blood smears from fever patients reexamined in the municipal microscopic examination station and all positive blood smears in Zibo City during the period from 2011 to 2018 were reexamined, and the blood smear preparation, dyeing, cleanliness and reexamination results were analyzed.

Results: A total of 2 141 negative malaria blood smears and 39 positive blood smears were re-reviewed by the municipal microscopic examination station of Zibo City from 2011 to 2018, with a 99.44% qualification rate of negative blood smears preparation, a 97.62% qualification rate of dyeing, a 93.65% qualification rate of cleanliness, and a 100% consistence with the re-review, and no missing diagnosis was found. A total of 39 positive blood smears were re-reviewed, with a 46.15% qualification rate of blood smears preparation, a 61.54% qualification rate of dyeing, a 76.92% qualification rate of cleanliness, and a 97.44% consistence with the re-review, and a blood smear mistaking the species was found. There were significant differences in the qualification rate of blood smears preparation and dyeing among all districts (counties) in Zibo City (all values < 0.05), and no significant difference was detected in the qualification rate of blood smear cleanliness ( = 13.72, >0.05), while significant differences were seen in the qualification rate of blood smears preparation, dyeing and cleanliness each year from 2011 to 2018 (all values < 0.05).

Conclusions: The quality of malaria blood smears is high in all districts of Zibo City; however, the quality of city-level blood smears remains to be improved. Further actions to improve the training of grassroots microscopic examinations and quality control of malaria blood smears are required to ensure the capability of microscopic examinations of during the malaria post-elimination stage.