Medical and environmental social scientists have recently become interested in how health brings human and nonhuman animals together. Th is article discusses historical approaches to this question. It then explores applied disease ecology, which examines how anthropogenic landscape change leads to "disease emergence. " Th e article goes on to review two critical approaches to the question. Critics of biosecurity concern themselves with the ways in which animal and human lives are regulated in the context of "emerging diseases" such as avian infl uenza and foot and mouth disease. Scholarship on human-animal "entanglement" focuses on the ways in which disease, instead of alienating humans from other life forms, brings their intimate relationships into sharper relief. Th e article argues that health is one terrain for developing a critical environmental analysis of the production of life, where life is the ongoing, dynamic result of human and nonhuman interactions over time.

This introductory article maps out the parameters of an emerging field of medical anthropology, human animal health, and its potential for reorienting the discipline. Ethnographic explorations of how animals are implicated in health, well‐being, and pathogenicity allow us to revisit theorizations of central topics in medical anthropology, notably ecology, biopolitics, and care. Meanwhile, the conditions of the Anthropocene force us to develop new tools to think about human animal entanglement. Anthropogenic change reorients debates around health and disease, but it also requires us to move beyond what some consider the traditional boundaries of the discipline. Zoonotic diseases, veterinary medicine, animal therapeutics, and food and farming are examples of topics that force such movement.

Drawing on participant‐observation in Nicaraguan dengue prevention campaigns and a series of semistructured interviews with Nicaraguan health ministry personnel, this article shows how community health workers (CHWs) balanced two kinds of “medical citizenship.” In some situations, CHWs acted as professional monitors and models of hygienic behavior. At other times, CHWs acted as compassionate advocates for their poor neighbors. In 2008, Nicaragua's Sandinista government moved to end a long‐standing policy of paying CHWs, recasting them as citizen–volunteers in a “popular struggle” against dengue. Although CHWs approved of the revival of grassroots advocacy, they were hostile to the elimination of compensation. Framing this ambivalence as part of CHWs’ desire to serve as “brokers” between the poor and the state, I suggest that attention to medical citizenship provides insight into the sometimes contradictory ways in which CHWs engage the participatory health policies now taking hold in Latin America and elsewhere.

While the proliferation of industrial toxic substances over the past century has had drastic environmental and bodily effects, conventional methods of measuring and mitigating those effects continue to produce uncertainty. The project of living in a toxic world entails ethical, technical, and aesthetic efforts to understand toxicity as a contingent encounter among beings, systems, and things, rather than as a fundamental characteristic of particular substances. Anthropologists do not just observe such encounters; they live and work within them. This review examines recent anthropological research on toxicity, proposing that responses to toxic disaster and occupational exposure, as well as acts of familial, state, or corporate care, are all modes of “toxic worlding.” The review concludes with a summary of recent research in collaborative and engaged anthropology, suggesting that such approaches are essential not so much for purifying or detoxifying the world as for making it otherwise. Expected final online publication date for the Annual Review of Anthropology, Volume 49 is October 21, 2020. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Nicaraguan Ministry of Health protocols for the control of Aedes aegypti, the mosquito that transmits dengue fever, hinge on an aesthetic ordering of the urban household, one in which mosquitoes, like garbage and dirt, do not belong. Management regimes such as this appear to rely on an alienation of people—and in the case of dengue, women in particular—from the urban natures in which they live. In this article, I draw on 18 months of research with Nicaraguan community health workers (brigadistas) for whom mosquito abatement involved an opening, rather than a closing, of the landscape. Brigadistas, especially female brigadistas, took deep pleasure in learning about mosquito–human lifeworlds, a pleasure I call “ecological aesthetic.” Ecological aesthetics—patterns of connection that are identifiable only through performance—contrasted to the more familiar aesthetics identifiable in the ministry's ordering of the household. Although the latter aesthetic has human control over life at its core, the former emphasizes entanglement, a relational knowledge of life. I suggest some implications of this idea for future anthropological studies of “the politics of life.”