A Geospatial Assessment of Environmental Variability in Puerto Rico and Its Relation to Confirmed Dengue Fever Cases

Vector-borne diseases such as dengue fever, chikungunya, and Zika pose a major threat to the health of Caribbean communities. Aedes aegypti (Ae. aegypti), the primary vector of these viruses, is dependent on humans for reproduction, and has been detected in populated areas within Puerto Rico. The vector's lifecycle and its transmission of dengue in Puerto Rico have been connected to specific environmental conditions. This study examined environmental conditions related to Confirmed Dengue Fever Cases (CDFC) for Puerto Rico from January 2009 - December 2013 by modeling the distribution of dengue-infected Ae. aegypti and its relationship to a suite of environmental variables. This project used monthly National Aeronautics and Space Administration (NASA) Terra/ Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Water Index (NDWI), along with day and night land surface temperature (DLST / NLST) products, Geostationary Operational Environmental Satellite system Puerto Rico Water Energy Balance (GOES-PRWEB) humidity products, and Climate Hazards Group InfraRed Precipitation and Satellite (CHIRPS) total precipitation (TP) modeled data. A Maximum Entropy Species Distribution Model and Earth Trends Modeler within Clark Labs' TerrSet were used to spatially delineate monthly Ae. aegypti habitat suitability, determine the permutation importance of the environmental conditions, and quantify island-wide environmental trends. TP and DLST had the highest mean relative importance of the dynamic environmental variables, agreeing with several studies that climatic environmental conditions play a significant role in disease transmission.

Location

NASA Ames Research center

Term

Spring 2016

Partner(s)

University of Puerto Rico, Medical Sciences Campus
US Centers for Disease Control and Prevention (CDC) Dengue Branch
Puerto Rico Department of Health
El Colegio de la Frontera Sur (ECOSUR)

NASA Earth Observations

Aqua, MODIS
Terra, MODIS
TRMM, PR
Polar Orbiting Environmental Satellites, AVHRR

Team

Andrew Nguyen (Project Lead)
Martha Sayre

Advisor(s)

Dr. Juan Torres-Pérez (Bay Area Environmental Research Institute)

Project Video