Associations between biotic and abiotic factors and Chagas disease vector abundance in palm trees across different habitat types

Jason Soriano, a freshman from University of California Berkeley, worked with Dr. Nicole Gottdenker and Christina Varian to investigate the factors influencing the abundance of an important disease vector.

Abstract:  In the Americas, an estimated 8 million people are infected with Chagas disease, a tropical, vector-borne infectious disease that can be life threatening if not properly treated. It is caused by the protozoan Trypanosoma cruzi which is transmitted by triatomine insect vectors called Rhodnius pallescens , reduviid bugs that are more commonly referred to as “kissing bugs” for their characteristic bites proximal to the lips and eyelids of humans. In Panama, sylvatic transmission of T. cruzi commonly occurs in the crown of the Attalea butyracea palm, the region of the palm tree where kissing bugs live. However, transmission can often spillover into human populations when infected vectors come into contact with humans. Previous studies have proven that land use change (e.g. deforestation) increase R. pallescens abundance, but the underlying mechanisms as to why this pattern occurs are largely unknown. Therefore, this research serves to shed some light on potential biotic and abiotic factors associated with vector abundance in A. butyracea palm trees across different habitat types. Through data visualization and statistical analysis of field data collected from four sites in central Panama, we show that microenvironment factors (primarily dead organic matter, relative humidity, and number of connected trees) are significantly correlated with R. pallescens abundance. Evaluating mechanisms as potential targets of palm management strategies aiming to control R. pallescens abundance will ultimately minimize disease risk and uphold the health, safety, and welfare of vulnerable communities.

Download (PDF, 4.69MB)