Spatial Distribution of <i>Anopheles sinensis</i>and Its Relationship with Natural Environmental Factors in Wanning County on Hainan Island, China

Anopheles sinensis is widely distributed in Wanning County, it is necessary to understand the spatial distribution characteristics of Anopheles sinensis in order to maintain the elimination of malaria in Wanning. During May and October 2009, we sampled adult mosquitoes at 36 villages within Wanning County on Hainan island, and collected meteorological and geographical data at each sampling site. We used these data to analyze the spatial distribution of adult Anopheles sinensis mosquitoes, and logistic regression analysis was applied to explore the association of the spatial distribution of Anopheles sinensis with the geographical and meteorological factors. We found that the density of Anopheles sinensis showed a significant positive spatial correlation. From May to October, on the whole, the high-density area was located in the central part of Wanning County. But each month there was a relatively high-density cluster, and their location and range were not exactly the same. From east to west, the density of Anopheles sinensis increased initially and then decreased, but from south to north, there were different trends in the periods of May to August and September to October. Logistic regression analysis showed that the main environmental factors related with the distribution of Anopheles sinensis were land use type, soil type, distance to road, air pressure and relative humidity. These analysis results showed that the distribution of Anopheles sinensis had obvious spatial heterogeneity in Wanning County, which was related with geographical and meteorological factors. The mechanism of these environmental factors on the distribution of Anopheles sinensis needs to be further studied.