A historical database is being constructed within the HEALTHY FUTURES project to investigate past outbreaks and incidences of malaria, schistosomiasis and RVF in eastern Africa in relation to possible environmental, social, economic and political factors. Primarily drawing on documentary archival sources, the period under consideration covers the past one hundred years or so, when documented history began in eastern Africa with the arrival of European missionaries and colonialism. To this effect, a wide range of archives in eastern Africa and the United Kingdom have been visited and a wide range of sources consulted, including ministry files, private papers, colonial reports and the accounts of intrepid missionaries describing the ‘dark continent’.
Image 1: Lake Albert: A study site
Documentary evidence is more recently receiving attention as a valuable method of reconstructing past climates, particularly for the pre-instrumental period. Historical climatology is the study of such evidence, primarily in relation to the effects of environmental and climate changes on historical human society and development. In addition to reconstructing temporal and spatial patterns of weather and climate, historical climatology explores the vulnerability of past societies to climate variations and climate events, and considers past narratives and social representations of climate.
Documentary sources are also an important tool in examining the historical patterns of disease. Written records tell of infectious disease outbreaks triggered by consequences of both higher and lower temperatures. Warmer climates tend to favour the propagation of bacteria, parasites, mosquitoes and other host vectors or animals, leading to increased incidence of disease, while the potential social response of population growth and movement may facilitate the spread of disease. In cooler climates, on the other hand, outbreaks may result from the biological impacts suffered by societies, such as under-nutrition and weakened immunity, and from social adaptations such as hunger-related mobility, crowding and shared indoors-living with animals. For example, analysis of the Chinese imperial archives over the past 8 centuries indicates 35% more occurrences of major epidemics during colder periods than during warmer periods.
Based on such historical analysis of written records, the historical database of the HEALTHY FUTURES project will contribute to building knowledge on disease outbreaks and epidemics in eastern Africa and their possible links with environmental, social, cultural and political influencing factors. Archival documentary sources can provide a wealth of information otherwise unobtainable and can strengthen examination of the environment-disease relationship through providing historical insights into possible mechanisms of the relationship, thereby also contributing to current debates on the impacts of environmental change on health.