This thesis investigates the recent rise to dominance in international health of 'partnership', an organizational form that has become prominent, some say requisite, in infectious disease research and control efforts in low-income countries around the world. Since the late 1990s, hundreds of large-scale transnational collaborative undertakings involving 'partners' from the public and private sectors and civil society, as well as countless smaller partnerships operating on regional and national levels, have come into being. Fuelled by substantially increased donor funding for reducing the burden of communicable diseases in poor countries, the spread of partnership – a notion connoting mutuality and equity – occurs in contexts characterized by profound disparities in power and resources. These contrasts are particularly pronounced in international health, a field linking disparate people, interests, and places in the global North and South, raising the question of how partnership actually plays out in practice. This historically-grounded ethnographic examination of the partnership phenomenon poses two interrelated questions: How does partnership happen? How do we study the processes through which partnerships form and function?

I address these questions by examining a partnership engaged in malaria research and control in Tanzania. Malaria – a 'disease of poverty' that, without sufficient socioeconomic improvements, often defies technological interventions – serves as the sociohistorical frame for this study. It offers a window for exploring the changing relationships between science and governance during a century of international control efforts in tropical Africa. By tracking knowledge practices of different parties, a pivotal activity in (health) development interventions, I trace shifting contours and dynamic interactional structures of a partnership, analyzing the indeterminate, sometimes contentious processes through which disparate agents and organizations seek to create a functioning whole. Exploring the often-derided elasticity and ambiguity of partnership in social reality, I show how the term vanishes from the discursive plane yet appears to remain operative at the level of practice. Especially at the lower echelons, it becomes enmeshed into patron-client dynamics, enabling influential actors to extend their power base by controlling resources and coercing subordinates. Finally, I examine how sociocultural conventions and language practices during data collection shape, even ‘distort,’ expert knowledge about malaria.