Potential distribution of mosquito vector species in a primary malaria endemic region of Colombia

Altamiranda Saavedra, Mariano Augusto | 2017

Rapid transformation of natural ecosystems changes ecological conditions for important human disease vector species; therefore, an essential task is to identify and understand the variables that shape distributions of these species to optimize efforts toward control and mit- igation. Ecological niche modeling was used to estimate the potential distribution and to assess hypotheses of niche similarity among the three main malaria vector species in north- ern Colombia: Anopheles nuneztovari, An. albimanus, and An. darlingi. Georeferenced point collection data and remotely sensed, fine-resolution satellite imagery were integrated across the Urabá –Bajo Cauca–Alto Sinú malaria endemic area using a maximum entropy algorithm. Results showed that An. nuneztovari has the widest geographic distribution, occupying almost the entire study region; this niche breadth is probably related to the ability of this species to colonize both, natural and disturbed environments. The model for An. dar- lingi showed that most suitable localities for this species in Bajo Cauca were along the Cauca and Nechı́ river. The riparian ecosystems in this region and the potential for rapid adaptation by this species to novel environments, may favor the establishment of popula- tions of this species. Apparently, the three main Colombian Anopheles vector species in this endemic area do not occupy environments either with high seasonality, or with low season- ality and high NDVI values. Estimated overlap in geographic space between An. nuneztovari and An. albimanus indicated broad spatial and environmental similarity between these spe- cies. An. nuneztovari has a broader niche and potential distribution. Dispersal ability of these species and their ability to occupy diverse environmental situations may facilitate sym- patry across many environmental and geographic contexts. These model results may be useful for the design and implementation of malaria species-specific vector control interven- tions optimized for this important malaria region.