Aedes aegypti rose to international notoriety as a host for the Zika virus, a disease linked to babies born with health issues. The mosquito is also a vector for other viral diseases, including dengue, chikungunya, and yellow fever. By ethnographically investigating the implementation of three seemingly similar projects in Brazil modifying A. aegypti to use them to control diseases, I want to explore how each project serves to produce a different model for envisioning the articulation between the state, public health, and science, between the country and the rest of the world. My research asks whether in these projects, as mosquitoes are modified to curtail the capacity to transmit diseases, there is also an effort to portray and promote Brazil as a country that can export knowledge and technology of health solutions. How are modified mosquitoes and the country itself turned into what we can call "vectors of health"? Brazil is described as the "gold standard" for these techniques: the tropical weather, the expanding urban landscapes, and the A. aegypti swarming in homes (often resistant to insecticides after generations of being sprayed on) are all pictured as characteristics increasing the challenges and, if overcome, proving the technique's success. My research builds upon, and expands, scholarship examining how scientific practices can shape and make "places," by examining how both biological (ecological, evolutionary, physiological, climatic) and anthropological theories can make "global," "Southern," or "Brazilian," came to matter in new ways. In addition, this dissertation seeks to add to scholarship on political debates about anthropogenic effects on the livable world by examining how understanding the relationship between health and the environment through the lenses of different scales (molecular, national, ecosystem, regional, global) can also shape the development and implementation to disease responses.