................................................................................................................................... iii ACKNOWLEDGEMENTS ............................................................................................................. v TABLE OF CONTENTS ............................................................................................................... vii LIST OF TABLES ........................................................................................................................ xiv LIST OF FIGURES ..................................................................................................................... xvii LIST OF ABBREVIATIONS ..................................................................................................... xviii CHAPTER 1 REVIEW OF THE LITERATURE ........................................................................... 1 1.1 Summary ............................................................................................................................. 1 1.2 Types of Mother-to-Child Transmission of HIV ................................................................ 1 1.2.1 Intrauterine Transmission ...................................................................................... 2 1.2.2 Intrapartum Transmission ...................................................................................... 2 1.2.3 Postpartum Transmission ....................................................................................... 3 1.3 Epidemiology of HIV MTCT and High Risk Populations ................................................. 4 1.4 Environmental and Behavioral Risk Factors for HIV MTCT ............................................ 5 1.5 Genetic Risk Factors for HIV MTCT ................................................................................. 7 1.5.1 Chemokines and Chemokine Receptors ................................................................ 8 1.5.2 CCR5 ...................................................................................................................... 9 1.5.3 CXCR4 ................................................................................................................. 10 1.5.4 CCR2 .................................................................................................................... 11 1.5.5 CX3CR1 ............................................................................................................... 12 1.5.6 DCSIGN ............................................................................................................... 13