Factors Associated with Pesticide Resistance in Culex Mosquitoes

Factors Associated with Pesticide Resistance in Culex Mosquitoes by Jude Akpan BS, Walden University, 2013 Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Public HealthEpidemiology Walden University May 2019 Abstract In recent years mosquito-borne diseases have reemerged, largely because of pesticide resistance. The mosquitoes develop resistance to pesticides because of broad and repeated uses of pesticides. Preventing the development of pesticide resistance requires proper understanding of the environmental factors potentially associated with the development of the resistance. The purpose of this study was to investigate the environmental factors associated with the resistance to pesticides by the Culex mosquitoes. This correlational study included the analysis of archived data samples (N = 29,794) from the Field Cage Tests results conducted between 2013 and 2017 by a large county public health department. The compartmental model was used to help understand and interpret study findings. To examine the associations between the independent variables (i.e., wind speed, temperature, humidity, time, month, and weather conditions) and the dependent variable (i.e., pesticide resistance), chi-square and multiple logistic regression analyses were performed. The results showed that the odds of mosquitoes developing resistance were 2.1 times higher during high temperatures than at low temperatures [x(1) = 346.5, p = . 000]; the resistance was 1.5 times higher during high humidity than in low humidity [x(1) = 7.23, p = . 007]; and the odds of mosquitoes developing resistance to pesticides in August were 3 times higher than when sprayed in June or July [x (2) = 702.606, p =In recent years mosquito-borne diseases have reemerged, largely because of pesticide resistance. The mosquitoes develop resistance to pesticides because of broad and repeated uses of pesticides. Preventing the development of pesticide resistance requires proper understanding of the environmental factors potentially associated with the development of the resistance. The purpose of this study was to investigate the environmental factors associated with the resistance to pesticides by the Culex mosquitoes. This correlational study included the analysis of archived data samples (N = 29,794) from the Field Cage Tests results conducted between 2013 and 2017 by a large county public health department. The compartmental model was used to help understand and interpret study findings. To examine the associations between the independent variables (i.e., wind speed, temperature, humidity, time, month, and weather conditions) and the dependent variable (i.e., pesticide resistance), chi-square and multiple logistic regression analyses were performed. The results showed that the odds of mosquitoes developing resistance were 2.1 times higher during high temperatures than at low temperatures [x(1) = 346.5, p = . 000]; the resistance was 1.5 times higher during high humidity than in low humidity [x(1) = 7.23, p = . 007]; and the odds of mosquitoes developing resistance to pesticides in August were 3 times higher than when sprayed in June or July [x (2) = 702.606, p = . 000]. Study findings may be used to help with the development of more effective methods for vector control thereby reducing the numbers of nuisance and diseasecarrying mosquitoes along with a possible reduction in the incidence of mosquito-borne diseases and related human morbidity and mortality. Factors Associated with Pesticide Resistance in Culex Mosquitoes by Jude Akpan Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Public HealthEpidemiology Walden University May 2019 Dedication To the Almighty God is the Glory. I dedicate this dissertation to my parents: Jude Akpan Sr. (late father) and Augusta Jude Akpan (mother). Also, to my beloved children: Cardinal Jude Akpan, Alex Jude Akpan, and Gloria Jude Akpan. Acknowledgments I want to thank several persons who have made it possible for me to finish this stage of my academic and professional life: my dissertation committee chair, Dr. Ernest Ekong; my committee member, Dr. Richard Jimenez; and Dr. James Rohrer, my URR.