Spatial change in the risks of Plasmodium vivax and Plasmodium falciparum malaria in China, 2005–2014

Abstract

Abstract Objective Despite the declining trend of malaria incidence over the last decade, Plasmodium falciparum malaria has increased in China both in terms of the number of case and geographical coverage. Thus, to improve the control intervention, we examined the change in the risk of both Plasmodium vivax and Plasmodium falciparum malaria across China during 2005–2014. Methods We applied logistic regression model to understand change in the risk of Plasmodium vivax and Plasmodium falciparum malaria in each county across the study period, and linear regression model to examine annual change in longitude and latitude of affected areas. Results The risk of Plasmodium falciparum malaria significantly increased with latitude and longitude, indicating that the incidence rate of Plasmodium falciparum malaria increased in the northern and eastern, or decreased in south and western China. Similarly, latitude and longitude of counties with Plasmodium falciparum significantly associated with year, showing annual increase in P. falciparum affected counties within the north and east. For Plasmodium vivax, the risk increased with latitude and longitude, but the longitude significantly decreased, and no significant change in latitude. Conclusion The risk of both Plasmodium falciparum and Plasmodium vivax malaria increased in the northern and eastern China, and was more noticeable for P. falciparum. An underlying cause of the increased malaria risk needs further investigation.