Assessment of Malaria Microscopy Competency at Primary Health Institutions in the Chongqing Municipality

Background: In April 2019, Chongqing passed the national malaria elimination assessment. However, around 30 imported malaria cases are still being reported every year, and Anopheles sinensis was widely distributed in Chongqing, meaning the risk of malaria resurgence still exists. Early diagnosis and treatment for malaria cases are effective measures to prevent malaria resurgence. The primary health institutions are the first station where potential malaria cases may seek treatment. The competency with which primary health institutions diagnose malaria will directly affect the timeliness of malaria diagnosis. Nowadays, most primary health institutions in Chongqing use microscopy to confirm malaria cases. This study assessed the microscopy competence of primary health institutions, studied and analyzed the results, and provided a scientific basis for malaria prevention and control after malaria elimination in Chongqing. Methods: According to the stratified sampling principle, four plasmodium microscopy technicians (156 in total) were selected from each of the 39 districts/counties of Chongqing to test the plasmodium microscopy competence. Descriptive statistical analysis, correlation analysis, spatial self-correlation analysis, and ROC curve analysis were carried out on the test results. Result: The average of the technicians' test scores was 4.33 ± 0.47 (min: 3, mid: 4.5, max: 5); The spatial clustering of the scores was significant (MoranI = 0.338, Z = 3.618, P < 0.01). The test scores were positively correlated with the "level of work institutions" (R = 0.21, P < 0.01) but were negatively correlated with "age" (R = -0.31, P < 0.01). The highest Sensitivity of the technicians' microscopy was in qualitative diagnosis (98.92%, CI: 98.00-99.69%). The Delong's test showed that the diagnostic efficiency of the technicians' microscopy to P. falciparum was the best (P < 0.01), however to P. ovale was the worst (P < 0.01). Conclusion: The microscopy technicians in primary health institutions in Chongqing have good microscopy competency in qualitative diagnosis, but there were deficiencies in the identification of plasmodium species. Township level health institutions in Central China have weaker microscopy than those in other areas.