Indexing immunity to malaria in South Africa in the 1920s and 1930s

During the 1920s and 1930s, medical authorities, municipal officials and employers of African farm labour in the lowveld regions of the former Transvaal constructed a system for classifying Africans in terms of their susceptibility or resistance to malaria. This classification system was based on imperfect knowledge about the actual distribution of malaria risk within the country. Yet it was employed to justify public health policies regarding malaria control and the segregation of urban communities in the lowveld region.