Louisiana State University LSU Digital Commons LSU Doctoral Dissertations Graduate School 2013 Epidemiology and molecular characterization of human and canine hookworm Ntombi B. Mudenda Louisiana State University and Agricultural and Mechanical College, [email protected] Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_dissertations Part of the Veterinary Pathology and Pathobiology Commons Recommended Citation Mudenda, Ntombi B., "Epidemiology and molecular characterization of human and canine hookworm" (2013). LSU Doctoral Dissertations. 1209. https://digitalcommons.lsu.edu/gradschool_dissertations/1209 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Doctoral Dissertations by an authorized graduate school editor of LSU Digital Commons. For more information, please [email protected]. EPIDEMIOLOGY AND MOLECULAR CHARACTERIZATION OF HUMAN AND CANINE HOOKWORM A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Veterinary Medical Sciences by Ntombi B. Mudenda BVM, University of Zambia, 2002 MS, Royal Veterinary College, 2004 December 2013 Dedicated to my sons, Penjani, Tabiso and Aiden ii ACKNOWLEDGEMENTS I would like to thank my mentor, Dr. John B. Malone for the guidance, encouragement and understanding. Many thanks to my graduate committee members, Dr. James Miller and Dr. Christopher Mores for their invaluable contribution to this work and for allowing me to use resources from their labs. I am also grateful to my Dean’s Rep, Dr. Lewis Gaston for being available and for his critic. Thanks to Dr. Wendy Wolfson, the staff and students in the shelter medicine program/rotation for the sample collection and the fruitful discussions we had. I am also grateful to the animal shelter managers for agreeing to be a part of this work. Special thanks to our collaborator at Case Western Reserve University, Dr. Ronald Blanton for helping me prepare for and organize the work in Brazil. I am very grateful to Dr. Mitermayer Reis and his laboratory staff at Oswaldo Cruz (FIOCRUZ), Salvador, Brazil for allowing me to work in their laboratory and facilitating my field work. Special mention goes to Dr. Jackson Costa for helping me organize the field work in Mutuípe, Bahia and Manuela Costa for being my very able Portuguese translator. I am grateful to the Mutuípe municipality Health Secretary for permission to work in the Central Laboratory and for the great welcome and pleasant work atmosphere from the staff in the lab. I am also grateful to Dr. Mariah Bavia for the facilitating my stay in Brazil. Thanks to Dr. Dwight Bowman and Janice Liotta for the donation of A. braziliense eggs and DNA which allowed me to complete my molecular work on canine hookworm. I am forever grateful to Dan Chisenhall for patiently teaching me PCR and giving me a better understanding of molecular techniques, for always being available to discuss my iii work and providing guidance. I am also grateful to Mr Michael Kearney for the guidance with statistics. To my fellow lab mates, past and present, Brooke Delcambre, Moara Martins, Cassan Pulaski, Ryan Avery, Paula Mischler and Patricia Smith (Miss Pat), I say thank you all for your input into my work and for creating a pleasant work environment. I also thank my fellow graduate students for willingly helping me whenever I needed it, both academically and otherwise. I could not have asked for better colleagues. This dissertation would not have been possible without funding from Pan American Health Organization, the LSU-SVM CORP grant as well as my personal sponsorship from the Fulbright Foreign Student grant and for that I am grateful. Last but definitely not least, I am eternally grateful to my supportive husband, Chewe Nkonde, my patient children, my mother for providing the American experience to our boys, my siblings, father, my whole family and friends across the globe for the encouragement, support and prayers. May God bless you all. iv TABLE OF CONTENTS ACKNOWLEDGEMENTS …………………………….…….…………………..………………… iii LIST OF TABLES ……………………………………………….…………………….. vii LIST OF FIGURES ………………………………………………………..…………… ix ABSTRACT …………………………………………………………………………………….…….... xi 1 BACKGROUND ..............................................................................................................1 1.1 Introduction ...............................................................................................................1 1.2 Ecological Niche Modeling ......................................................................................1 1.3 Soil-Transmitted Helminths ......................................................................................5 1.3.1 Biology of STHs .............................................................................................5 1.3.2 Public Health Significance ............................................................................11 1.3.3 Prevalence .....................................................................................................13 1.3.4 Diagnosis.......................................................................................................14 1.3.5 Treatment and Control ..................................................................................19 1.4 Human Hookworm Infection ..................................................................................23 1.4.1 Hookworm in Brazil .....................................................................................25 1.5 Common Intestinal Parasites of Dogs .....................................................................26 1.5.1 Biology and infection ....................................................................................27 1.5.2 Epidemiology of Canine Intestinal Parasites. ...............................................35 1.5.3 Diagnosis of Canine Gastrointestinal Parasites ............................................38 1.5.4 Treatment and control ...................................................................................40 1.6 References ...............................................................................................................41 2 MODELING THE ECOLOGICAL NICHE OF HOOKWORM IN BRAZIL BASED ON CLIMATE .............................................................................................................59 2.1 Introduction .............................................................................................................59 2.2 Materials and Methods ............................................................................................62 2.2.1 GDD ..............................................................................................................63 2.2.2 Moisture Adjusted GDD Model (MA-GDD) ...............................................64 2.2.3 GDD-Water Budget Gradient Model (GDD X WB) ....................................64 2.2.4 Calculation of Mean Transmission Time and Potential Transmission Cycles per Year ............................................................................................64 2.2.5 Model Validation ..........................................................................................65 2.2.6 Statistical Analysis ........................................................................................65 2.3 Results .....................................................................................................................66 2.4 Discussion ...............................................................................................................70 2.4.1 MA-GDD Index and Transmission Cycles ...................................................71 2.4.2 GDDxWB Index ...........................................................................................73 2.4.3 Data Validation .............................................................................................74 v 2.4.4 Other Environmental Factors ........................................................................75 2.5 References ...............................................................................................................76 3 HOOKWORM AND OTHER SOIL TRANSMITTED HELMINTHS AMONG PATIENTS IN MUTUÍPE, BRAZIL .............................................................................83 3.1 Introduction .............................................................................................................83 3.2 Materials and Methods ............................................................................................86 3.2.1 Study Area ....................................................................................................86 3.2.2 Parasitological Survey ..................................................................................86 3.2.3 Larvae Culture and Examination ..................................................................87 3.2.4 Preparation and Storage of Fecal Samples ....................................................88 3.2.5 DNA Extraction from Infective Larvae and Fecal Samples .........................89 3.2.6 PCR for N. americanus and A. duodenale Differentiation ...........................89 3.3 Results .....................................................................................................................91 3.3.1 Hookworm Infection .....................................................................................93