This book presents an overview of paratransgenesis, an innovative approach to the control of infectious disease. In paratransgenic interventions, an arthropod vector’s bacterial symbiont is transformed to express molecules directed against a target pathogen. The vector is inoculated with the transformed bacterium via a bait formulation. The bacteria replicate in the vector and export antipathogen molecules, resulting in interruption of disease transmission. Paratransgenesis offers a sustainable, environmentally friendly alternative to vector eradication using pesticides, which is limited by environmental toxicity, cost, and development of vector resistance.