Trend and spatiotemporal distribution characteristics of malaria in mainland China – 2010 to 2017: an analysis on national registration data

  Objective  To analyze prevalence trend of malaria and its spatiotemporal distribution characteristics in China for further promoting malaria control.

  Methods  Nationwide malaria incidence data of 2010 – 2017 were collected from public health science data website of Chinese Center for Disease Control and Prevention and the population data were extracted from yearly China Statistical Yearbook of the same period. Empirical mode decomposition was adopted to identify the overall trend of malaria incidence and mathematical models were constructed to estimate variations in annual malaria incidence rate; ArcGIS 10.7 and SaTScan 9.01 software were utilized in spatial analysis of the incidence data.

  Results  Totally 29 687 malaria cases were reported in mainland China during the 8-year period, primarily with vivax malaria cases aged 0 – 20 and ≥ 55 years and falciparum malaria cases aged 21 – 54 years. The overall incidence showed a significantly downward trend (odds ratio = 0.441, 95% confidence interval: 0.375 – 0.508). The hot spots of malaria incidence were mainly concentrated in the southwest border and some coastal areas of China but no obvious clustering of cold spots was observed. Totally 5 regions with spatio-temporal clustering of malaria incidence were identified and the high incidence clusters occurred mainly before 2013. Standard deviation ellipse analysis demonstrated that the region with higher malaria incidence drifted generally from southwestern area to northeastern area and the spatial range of malaria epidemic expanded to eastern provinces during the period.

  Conclusion  From 2010 to 2017 in mainland China, the malaria incidence displayed downward trend generally and populations in southwestern and eastern regions were at a higher risk of malaria incidence.