Malarial immunities in nineteenth-century west Africa and the Caribbean.

Military records make it possible to study the cause of death of British and French soldiers in West Africa and the Caribbean between about 1819 and 1914. These records are significant because they trace the quantitative pattern of immunity, or lack of it, among soldiers recruited in one region and serving in another. In the Caribbean, a childhood Caribbean disease environment produced no greater immunity to malaria than childhood in the British isles did. Childhood in West Africa, however, produced a degree of immunity to malaria is the Caribbean. For soldiers whose childhood disease environment was in Europe, increased deaths in the tropics were greater in West Africa than they were in the West Indies. The relative importance of malaria as a cause of death increased over this century, largely because death from other causes in the tropics declined faster than malaria deaths did. The greatest improvement in malaria death rates took place between the 1840s and 1870s as a result of empirical public health measures-not after the discovery of the mosquito vector at the end of the century.