University of Miami Scholarly Repository Open Access Dissertations Electronic Theses and Dissertations 2007-12-21 Analyses of Dengue Fever and Aedes aegypti (Diptera: Culicidae) Larval Habitats in a Tropical Urban Environment of Costa Rica using Geospatial and Mosquito Surveillance Technologies Adriana Troyo University of Miami, [email protected] Follow this and additional works at:https://scholarlyrepository.miami.edu/oa_dissertations Recommended Citation Troyo, Adriana, "Analyses of Dengue Fever and Aedes aegypti (Diptera: Culicidae) Larval Habitats in a Tropical Urban Environment of Costa Rica using Geospatial and Mosquito Surveillance Technologies" (2007).Open Access Dissertations. 18. https://scholarlyrepository.miami.edu/oa_dissertations/18 This Open access is brought to you for free and open access by the Electronic Theses and Dissertations at Scholarly Repository. It has been accepted for inclusion in Open Access Dissertations by an authorized administrator of Scholarly Repository. For more information, please contact [email protected]. UNIVERSITY OF MIAMI ANALYSES OF DENGUE FEVER AND AEDES AEGYPTI (DIPTERA: CULICIDAE) LARVAL HABITATS IN A TROPICAL URBAN ENVIRONMENT OF COSTA RICA USING GEOSPATIAL AND MOSQUITO SURVEILLANCE TECHNOLOGIES By Adriana Troyo A DISSERTATION Submitted to the Faculty of the University of Miami in partial fulfillment of the requirements for the degree of Doctor of Philosophy Coral Gables, Florida December 2007 UNIVERSITY OF MIAMI A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy ANALYSES OF DENGUE FEVER AND AEDES AEGYPTI (DIPTERA: CULICIDAE) LARVAL HABITATS IN A TROPICAL URBAN ENVIRONMENT OF COSTA RICA USING GEOSPATIAL AND MOSQUITO SURVEILLANCE TECHNOLOGIES Adriana Troyo Approved: ________________ _________________ Dr. John C. Beier Dr. Terri A. Scandura Professor of Medical Entomology Dean of the Graduate School ________________ _________________ Dr. Douglas O. Fuller Dr. Arba Ager Professor of Geography Professor of Microbiology ________________ _________________ Dr. Kristopher L. Arheart Dr. Clyde B. McCoy Professor of Statistics Professor of Epidemiology ________________ Dr. Dave D. Chadee Professor of Medical Entomology University of the West Indies TROYO, ADRIANA (Ph.D., Interdepartmental Studies) Analyses of dengue fever and Aedes aegypti (December 2007) (Diptera: Culicidae) larval habitats in a tropical urban environment of Costa Rica using geospatial and mosquito surveillance technologies Abstract of a dissertation at the University of Miami. Dissertation supervised by Professor John C. Beier. No. of pages in text. (142) Dengue is currently the most important arboviral disease globally and is usually associated with built environments in tropical areas. Control measures are currently focused on community participation in control of the vector Aedes aegypti and larval source reduction. In Costa Rica, dengue fever is a relatively recent re-emerging disease and has become a serious public health problem. Remotely sensed information can facilitate the study of urban mosquito-borne diseases like dengue by providing multiple temporal and spatial resolutions appropriate to investigate urban structure and ecological characteristics associated with infectious disease. Initial studies showed that although dengue is a serious public health problem in Costa Rica, there is a need for interdisciplinary scientific research to guide vector control. Therefore, the dengue situation in Puntarenas, Costa Rica, and applications of remote sensing to study infectious diseases like dengue within urban environments was analyzed. Satellite imagery of high and medium spatial resolution was obtained to evaluate relationships between urban structure and incidence of dengue fever at the locality level. Using the satellite imagery, a geographical sampling method was developed and applied for seasonal entomological field surveys in Puntarenas. Very high resolution imagery from QuickBird was utilized to determine the relationships between Ae. aegypti larval habitat abundance and tree cover or built areas. Results showed that the most relevant Ae. aegypti larval habitats in Puntarenas were outdoor miscellaneous containers, cans and plastic food containers that fill with rain water in the wet season, while washtubs were the most productive habitats in the dry season. Dengue incidence and abundance of larval habitats in the urban environment were directly associated with tree cover and inversely associated with built areas. Environmental conditions and urban structure, as well as human behavior were related in different ways to dengue incidence and Ae. aegypti larval habitats. Overall, remotely sensed information was useful in developing sampling strategies for field surveys and determining factors within the urban environment that may promote persistence of mosquito larval habitats and increased dengue risk. The geographical methods and relationships revealed will be useful in determining target areas for more efficient vector control. Dedication: To my parents and grandparents, my greatest teachers along this journey. iii Acknowledgements: I would like to express my most sincere gratitude to colleagues at the University of Costa Rica, Facultad de Microbiologia, especially to Olger, Mayra, Adrian and everyone in the Department of Parasitology. A special thanks to Dr. Beier, Dr. Calderon, and Dr. Fuller for their continued guidance and unconditional collaboration throughout the entire research and writing process. I thank the people of Puntarenas, the local Ministry of Health, Dr. Velit, Dr. Sanchez. Also, to Lissette, Nelson, Iván, Adriana, Julio, and Christian for their extensive efforts in performing the field surveys. Thanks to everyone in the Global Public Health Program, University of Miami, for their helpful discussions and suggestions, especially Sherri Porcelain, Dave Chadee, Shouraseni Sen Roy, Daniel Impoinvil, Joseph Keating, and Tina Collazo. Lastly, I would like to show my appreciation to Drs. Beatriz Rodriguez, Patrick Lammie, and Barney Cline whose initial support and enthusiasm lead me to embark in this adventure. This research was supported by Grant Number P20 RR020770 from the National Center for Research Resources (NCRR), a component of the National Institutes of Health (NIH), and its contents are solely the responsibility of the author and do not necessarily represent the official view of NCRR or NIH. Research was also supported in part by University of Costa Rica, projects VI-803-A6-401 and VI 803-A6-039, and the University of Miami’s Graduate School, Medical Graduate School, and Department of Geography, College of Arts and Sciences. iv Table of Contents Page Introduction 1 Chapter I Remote Sensing and its applications in the Epidemiology of Vector-Borne Diseases: The Urban Challenge 4 Remote sensing in vector-borne diseases of medical importance 7 Tick-borne diseases 8 Trypanosomiasis 8 Leishmaniasis 9 Onchocerciasis 10 Mosquito-borne diseases 10 Remote sensing applications and urban vector-borne diseases 12 Concluding remarks 15 II Dengue in Costa Rica: the gap in local scientific research 17 Dengue and dengue hemorrhagic fever 18 Dengue and scientific research in Costa Rica 21 Scientific research related to dengue in Costa Rica 25 Possible reasons for the gap in local scientific research 30 Lessons from other countries in the region of the Americas 34 Additional benefits and possible negative consequences of local scientific research 37 Conclusions and recommendations 38 III Urban structure and dengue fever in Puntarenas, Costa Rica 42 Methods 45 Study site 45 Local data 47 Satellite imagery and data 48 Data analyses 53 Results 54 Meteorological influences on timing of dengue incidence 54 Seasonal dynamics of vegetation indices 56 Image classification and correlations with dengue incidence 57 Discussion 62 Conclusions 69 v IV A geographical sampling method for surveys of mosquito larvae in an urban area using high-resolution satellite imagery 71 Materials and methods 72 Results 79 Discussion 81 V Seasonal profiles of Aedes aegypti (Diptera: Culicidae) larval habitats in an urban area of Costa Rica with history of mosquito control 85 Materials and methods 87 Analyses 90 Results 92 Wet season 92 Dry season 98 Discussion 102 VI Urban structure and Aedes aegypti larval habitats in Puntarenas, Costa Rica 109 Materials and methods 111 Study site 111 Entomological data 111 Satellite imagery and image classification 112 Statistical analyses 114 Results 114 Discussion 117 Conclusions 120 References 127 vi