Projecting Future Distributions of Triatoma gerstaeckeri in the Southwestern United States and Northern Mexico

Abstract

Chagas disease, caused by the Trypanosoma cruzi parasite, is heavily present in Latin America, where it is the most important vector-borne disease. While not as common in Mexico and the United States, it is classified as endemic in parts of these countries. The vectors of Chagas disease are kissing bugs, belonging to the Triatominae subfamily. One of the kissing bug species, Triatoma gerstaeckeri, is native to parts of northern Mexico and the southern United States. This species has also been found to have an innate capability of carrying the T. cruzi parasite, making it of high epidemiological importance. This study assesses the current and future consequences of climate change and land use. Climatic projections up to 2060 and land use maps are used to show the possible geographic distributions of Triatoma gerstaeckeri in the coming years.

Using these parameters, a maximum entropy approach featured in the Maxent software package was utilized to predict future species distributions in northern Mexico and the southern US. A total of 10 models for each time period were created and evaluated with cross-validation, and the final map was included averages from all 10 models. The results show strong model robustness and validated the Maxent results. The final maps showed a northern and western distribution shift for T. gerstaeckeri from its current known range due to climate change and land use. While factors such as predator prevalence and in-depth habitat suitability were not used in this study, the findings provide a solid basis to monitor population shifts and possibly Chagas disease risk, in the future.