A global war against wild rodents: sanitary tensions, anti-rodent measures, and the spectre of sylvatic plague (1927–1950s)

The first half of the twentieth century witnessed debates on the part played by wild rodents on “conserving” the plague bacillus and eventually spreading it within national borders, and even beyond. This condition was christened by the Portuguese doctor Ricardo Jorge as sylvatic plague in 1926–1927. In the following years, sylvatic plague began to be seen as an important risk in places where an independent cycle of plague infection among wild rodents did not yet exist. This chapter examines three contexts where the spectre of sylvatic plague haunted health officers. Firstly, Angola, where the new concept framed a plague invasion by migratory gerbils coming from South Africa in 1932 and justified measures to destroy these animals. Secondly, the UK, where quarantine measures were applied in 1938–1939 against imported rodents to be exposed in zoos over the risks they could spread the sylvatic plague among local rodents. Finally, Brazil, where the menace of sylvatic plague appearing in the backlands and in the Amazon justified the creation of the Brazilian Plague National Service in 1941, and the deployment of anti-rat and anti-rodent measures in the 1940s and 1950s. Taken together, these contexts suggests that a truly global war against wild rodents unfolded in the second quarter of the twentieth century.