An introduction to the history of infectious diseases, epidemics and the early phases of the long-run decline in mortality

Abstract

This article, written during the COVID-19 epidemic, provides a general introduction to the long-term history of infectious diseases, epidemics and the early phases of the spectacular long-term improvements in life expectancy since 1750, primarily with reference to English history. The story is a fundamentally optimistic one. In 2019 global life expectancy was approaching 73 years. In 1800 it was probably about 30. To understand the origins of this transition, we have to look at the historical sequence by which so many causes of premature death have been vanquished over time. In England that story begins much earlier than often supposed, in the years around 1600. The first two 'victories' were over famine and plague. However, economic changes with negative influences on mortality meant that, despite this, life expectancies were either falling or stable between the late sixteenth and mid eighteenth centuries. The late eighteenth and early nineteenth century saw major declines in deaths from smallpox, malaria and typhus and the beginnings of the long-run increases in life expectancy. The period also saw urban areas become capable of demographic growth without a constant stream of migrants from the countryside: a necessary precondition for the global urbanization of the last two centuries and for modern economic growth. Since 1840 the highest national life expectancy globally has increased by three years in every decade.

Figure 1

Estimates of long‐run life expectancy at birth in England 1543–2011 Note: The data underling this figure derive for England & Wales 1543–1868 from Wrigley et al., Population history of England; the later nationwide series is from the Human mortality database. The urban and London series are from Woods, Victorian England and Wales. [Color figure can be viewed at wileyonlinelibrary.com]

Figure 2

Cohort survival curves for England 1650 and 2016 Note: The data for 1650 are based on a sample of reconstituted parish populations in 1650–9: Wrigley et al, English population history. The 2016 data is from the Human mortality database. [Color figure can be viewed at wileyonlinelibrary.com]

Figure 3

Cohort survival curves, London and England in the 1730s Note: London data is based on a sample of Quakers in 1730–39, drawn from Landers, Death and the metropolis. The provincial data is derived from the parish reconstitutions for 1730–39 in Wrigley et al., English population history. [Color figure can be viewed at wileyonlinelibrary.com]

Figure 4

Recorded burials and baptisms in the London Bills of Mortality 1675–1830 Note: Data from Marshall, Mortality, pp. 67, 70–1. [Color figure can be viewed at wileyonlinelibrary.com]

Figure 5

Crude death rate (deaths per thousand population) 1543–1869 Note: Data from Wrigley and Schofield, Population history. [Color figure can be viewed at wileyonlinelibrary.com]

Figure 6

Major diseases that declined before 1945 in England Source: Davenport and Smith, ‘Early history of public health’. Note these death rates derive from modern epidemiological studies, not from historic outbreaks which may have been different for a variety of reasons. [Color figure can be viewed at wileyonlinelibrary.com]