Seasonal prediction of the distribution of three major malaria vectors in China: Based on an ecological niche model

Against the backdrop of a global malaria epidemic that remains severe, China has eradicated indigenous malaria but still has to be alert to the risk of external importation. Understanding the distribution of vectors can provide an adequate and reliable basis for the development and implementation of vector control strategies. However, with the decline of malaria prevalence in recent years, the capacity of vector monitoring and identification has been greatly weakened. Here we have used new sampling records, climatic data, and topographic data to establish ecological niche models of the three main malaria vectors in China. The model results accurately identified the current habitat suitability areas for the three species of Anopheles and revealed that in addition to precipitation and temperature as important variables affecting the distribution of Anopheles mosquitoes, topographic variables also influenced the distribution of Anopheles mosquitoes. Anopheles sinensis is the most widespread malaria vector in China, with a wide region from the northeast (Heilongjiang Province) to the southwest (Yunnan Province) suitable for its survival. Suitable habitat areas for Anopheles lesteri are concentrated in the central, eastern, and southern regions of China. The suitable habitat areas of Anopheles minimus are the smallest and are only distributed in the border provinces of southern China. On this basis, we further assessed the seasonal variation in habitat suitability areas for these three major malaria vectors in China. The results of this study provide new and more detailed evidence for vector monitoring. In this new era of imported malaria prevention in China, regular reassessment of the risk of vector transmission is recommended. Malaria, as one of the most important insect-borne infectious diseases in tropical and subtropical regions, poses a serious disease burden worldwide. Malaria has been prevalent in China for more than 4,000 years, seriously endangering the health of the Chinese people and restricting socio-economic development. Nowadays, there are three major species of malaria transmission in China, Anopheles sinensis, Anopheles lesteri, and Anopheles minimus. Due to vector control and climate change in recent years, the distribution range of these Anopheles mosquitoes has changed. Here, we applied an ecological niche model to simulate the potential distribution as well as seasonal variation of three species of Anopheles and to identify the factors affecting their survival. The results revealed that precipitation, temperature, and topographic variables were important influences on the distribution of Anopheles mosquitoes. A wide region from the northeast (Heilongjiang Province) to the southwest (Yunnan Province) is suitable for An. sinensis. Suitable habitat areas for An. lesteri are concentrated in the central, eastern, and southern regions of China. The suitable habitat areas of An. minimus are the smallest, which are only distributed in the border provinces of southern China. This study provides new information for policymakers to develop vector control measures.