1. AIDS and Science -- 2. Politics and the Construction of Knowledge: AIDS Activism as a New Social Movement -- 3. Sponsoring Global Action: The Role of WHO -- 4. Local Action: Responding to AIDS in Brazil -- 5. Central Problems in a Peripheral Landscape: Negotiating Knowledge and Treating AIDS in Brazilian Medical Settings -- 6. War Metaphors in Germ Theory and Immunology: In Search of a New Paradigm -- 7. Conclusions