Early colonialism took shape in efforts to control trade routes, replacing hongo polities with its own stations. But at the end of the nineteenth century, new forms of logistical power emerged that would allow for a radical intensification of colonial control, a connection so tight I propose we need to approach it as ‘infrastructural empire’. Whereas much ink was spilled in colonial metropoles hailing the unlimited possibilities afforded by railways and motorable roads, the reach of colonial control in the Congo Basin actually proved quite limited. Across most of Central Africa, it was restricted to the slender lines of individual transport routes, and new forms of resistance beset the advancing logistical machinery. Whereas before colonization Africans had moved to the trade routes to impose taxation, now that these pathways became vehicles of colonial violence, they systematically moved away from them to avoid it. From the cover of the bush and at crucial nodes in the transport system, Africans started to sabotage the logistics on which the new colonial order relied. Such forms of resistance precipitated a colonial obsession with mastering unruly and impenetrable landscapes beyond the logistical reach of the colonial state.

Chapter 9 looks at the history of colonial medicine in French Africa. Eugène Jamot, the most famous French military doctor, spearheaded efforts in the 1920s to control sleeping sickness. These interventions were later extended to other endemic diseases such as yaws, syphilis and leprosy. Case-finding activities in every village, with on-the-spot treatment of infected patients with injectable drugs administered using unsterilised syringes and needles, led to massive infection with the hepatitis C virus of as many as half of some birth cohorts. Obviously, this could have resulted in the concurrent iatrogenic transmission of HIV, in the very parts of central Africa inhabited by the chimpanzee source of the virus.

Chapter 5 sets the stage for the rest of the story. While several infectious agents were exported from Africa to the Americas and the Caribbean during the slave trade, this was not the case with HIV, which indirectly confirms its relatively recent emergence in central African populations. This chapter briefly tells the story of the European colonisation of central Africa by France and Belgium. It explains how the Franco-Belgian incursion in south-east Cameroon during World War I (1914–16) created much greater intermingling of populations and may have provided a route for HIV to reach the Stanley Pool.

Chapter 6 explains how the process of colonisation profoundly altered the ways of life of peoples in the Belgian Congo, Moyen-Congo and Cameroon, through accelerated urbanisation and the pronounced gender imbalance in the cities that resulted from colonial policies. It focuses on Léopoldville, which for a few decades was essentially a labour camp. The chapter ends with a review of how the Stanley Pool, where Léopoldville and Brazzaville were located, has always been the natural terminus for all traffic in the huge River Congo basin, and thus a melting pot of dozens of ethnic groups.