Effects of Land Use and Land Cover Change (LULC) and Climate Change on Mosquito-Borne Disease Transmission in Colombia: An Integrated Spatiotemporal Approach

Human modification of the natural environment continues to create conditions under which mosquito-borne diseases thrive. In this project, I identify associations between environmental change and the Zika epidemic in Colombia in 2016. Colombia had the second highest number of Zika cases in the Americas after Brazil, totaling over 100,000 suspected and confirmed cases. Zika is an arboviral disease transmitted by Aedes mosquitoes. Previous work has shown that transmission of Zika depends on elevation, forest cover, urban cover, temperature, and precipitation. However, the impacts of changes in these factors, rather than their current states, have yet to be studied. I used spatiotemporal remote sensing imagery to measure the changes in forest cover, urbanization, temperature, and precipitation in Colombia and built a regression model to assess their relationship with the presence and incidence of Zika transmission. For comparison, I also observed the impacts of these variables on other mosquito-borne diseases in Colombia, including dengue and chikungunya (also transmitted by Aedes mosquitoes) and malaria (transmitted by Anopheles mosquitoes). Forest loss was positively associated with the presence of Aedes-borne diseases, whereas forest gain was negatively associated with the incidence of Aedes-borne diseases. In some cases, the environmental drivers' states across space and rates of change across time showed opposite effects on disease
presence, which highlights the importance of assessing environmental drivers spatiotemporally. As highly detailed datasets on environmental change become more accessible, more eco-epidemiological analyses like this project can help to clarify the impacts of environmental change on human health.