UVM Theses and Dissertations
Format:
Print
Author:
Lucero, David
Dept./Program:
Biology
Year:
2013
Degree:
PhD
Abstract:
Efforts to curtail Chagas disease in the. Americas have traditionally relied on heavy pyrethroid-based insecticide use. While successful in some countries, Guatemala and Bolivia have experienced a reemergence of insect vectors in part due to the ineffectiveness of insecticides in peri-domestic and sylvatic ecotopes. In these ecotopes, environmental factors are able to break down the insecticides.
As a consequence, domestic ecotopes are often reinfested as little as 4 months post-insecticide use. Ecohealth sustainable interventions take advantage of local resources to plaster homes, relocate livestock and educate homeowners on the risk of Chagas disease. Chapter 2 reports an evaluation of the success of the Ecohealth approach monitored with household surveys, Geographic Information Systems (GIS) and spatial statistics over space and time, and found that house infestation remained <5% 5 years after intervantions.
Similarly in Bolivia, high rates of house infestation have been attributed to reinfestation from sylvatic ecotopes and landscape features (e.g., animal corrals, proximity to town boundary, etc.) among other factors. Therefore, in Chapter 3, we report on sylvatic Chagas vectors collected with live bait traps and determined their blood meal profiles to provide insight into their movement. We optimized sensitive taxa specific qPCR hydrolysis probes to detect feeding specifically on hosts of epidemiological importance (e.g., chicken, dog and human) and used a vertebrate DNA cloning technique to widely survey for vertebrate blood meals. In a community near the sylvatic traps, we conducted person-hour household surveys to determine infestation clustering and risk associated with livestock and landscape features (e.g., proximity to road) with GIS and spatial statistics.
As a consequence, domestic ecotopes are often reinfested as little as 4 months post-insecticide use. Ecohealth sustainable interventions take advantage of local resources to plaster homes, relocate livestock and educate homeowners on the risk of Chagas disease. Chapter 2 reports an evaluation of the success of the Ecohealth approach monitored with household surveys, Geographic Information Systems (GIS) and spatial statistics over space and time, and found that house infestation remained <5% 5 years after intervantions.
Similarly in Bolivia, high rates of house infestation have been attributed to reinfestation from sylvatic ecotopes and landscape features (e.g., animal corrals, proximity to town boundary, etc.) among other factors. Therefore, in Chapter 3, we report on sylvatic Chagas vectors collected with live bait traps and determined their blood meal profiles to provide insight into their movement. We optimized sensitive taxa specific qPCR hydrolysis probes to detect feeding specifically on hosts of epidemiological importance (e.g., chicken, dog and human) and used a vertebrate DNA cloning technique to widely survey for vertebrate blood meals. In a community near the sylvatic traps, we conducted person-hour household surveys to determine infestation clustering and risk associated with livestock and landscape features (e.g., proximity to road) with GIS and spatial statistics.