Fenland ague in the nineteenth century.

Ague was central to the local construct of health and mortality for both the lay and the medically trained nineteenth-century Fenlanders. The disease was endemic in the marshes of Lincolnshire, Norfolk, Suffolk and Cambridgeshire for the greater part of the century, reaching epidemic proportions between 1826 and 1829, and 1857 and 1860. Mortality from ague was minimal and sporadic, but the disease precipitated a chronic state of ill-health and co-morbidity with other infectious and water-borne diseases of the nineteenth century, a state which profoundly affected the social and economic structures of the area. This paper examines the prevalence of ague, and its effect on mortality and morbidity in the Fens during the nineteenth century. In particular, it focuses on the Fenlanders' perception of ague. Local synonyms for the disease reflect their understanding of the way it was contracted-paludal fever, marsh fever, autumnal fever; and its effects and behaviour-intermittent fever, periodical fever, the quakes. They even reflect the character of the disease, personifying it as a familiar figure and suggesting a degree of intimacy-the Bailiff of the Marshes, Lord John's fever, Old Johnny Axey. Nineteenth-century authors believed ague to be malaria and often used the terms interchangeably. The high morbidity and low mortality from the disease and the seasonal pattern of primary infection and relapse suggest a benign, tertian malaria, caused by Plasmodium vivax (rather than the more fatal tertian, P falciparum). Yet, without clinical evidence of plasmodial infection in Fenlanders, the suggestion is still speculative.' Similarly, there is sparse historical evidence for the distribution of Anopheles mosquitoes, the vector for the parasite, in the Fens.2 However, local