Influenza pandemics during the Eighteenth Century

The medical profession of the eighteenth century was ill equipped to deal with influenza at any level. For most doctors, especially in the first six or seven decades of the century, influenza seemed to be spread or 'created' by atmospheric factors. Such theories could be complex. They usually invoked an unknown poison or spores carried in the air and/or specific winds, temperature changes, barometric pressures, or other meteorological factors to explain the appearance and spread of endemic diseases like influenza. To that extent, most eighteenth and early nineteenth-century articles on influenza are much more likely to contain elaborate meteorological tables than geographical reconstructions or statistics on morbidity or mortality.

Of course, we don't know the exact subtypes, but Influenza pandemics occurred at least three times in the eighteenth century: 1729-1730, 1732-1733, and 1781-1782. In addition there were two major epidemics that could possibly be considered pandemics, in 1761-1762 and 1788-1789. Of these, two warrant further discussion: the pandemic of 1729-1730 and the great pandemic of 1781-1782.

The 1729-1730 pandemic was the first recorded pandemic, most likely fostered by the age of discovery. Influenza apparently did not break out in North America until October 1732, when the disease was discovered widespread along the New England coast from Boston to southern Maine. Although the origins and termination of the 1729-1730 outbreak are unclear, it obviously was a pandemic, the first of a series that western European observers perceived as coming from Russia. An origin in Russia seems plausible, but there is no documentation of this. Initial reports were of substantial outbreaks in two widely separated Russian cities, Moscow and Astrakhan, on the Caspian Sea, in April, 1729. There were no further reports during the summer, but Influenza prevailed in Sweden in September and in Vienna in October. During November, Influenza was prevalent in Hungary and Poland, swept deep into Germany and appeared in London, Plymouth, York and Durham England, as well in Dublin, Ireland.

While quantitative evidence is lacking, the 1729-1730 pandemic caused sickness but relatively few deaths. Morbidity was extensive, but mortality was generally low, although the case-fatality rate was considered serious in northern Italy. Persons of all ages were stricken, but deaths were most numerous among the elderly and pregnant women.

The pandemic of 1781-1782 ranks with those of 1889-1890 and 1918-1919 as amongst the most widespread and dramatic outbreaks of disease in history. Unlike other pandemics of the eighteenth century, the pandemic of 1781-1782 had some interesting features that can be compared to the epidemics of the 20th century. A few general characteristics of this pandemic were noticed.
1. Eevidence of a spring wave in North Africa and North America in 1781
2. Diffusion of Influenza into the Eastern Hemisphere in 1781
3. Widespread outbreaks occurred within China and British-occupied India during the autumn of 1781
4. The pandemic started in China and spread westward in 1782.

It caused tens of millions of cases, spread as rapidly as existing transportation systems permitted, and not surprisingly, elicited volumes of medical writings.