Putting disease on the map
Posted 6 August, 2009 13:04 by Karla Baker
Maps are ever so helpful when it comes to finding one’s way around the world. They are the obvious choice if you need to know how to get to Devon, for example, and they help to put the planet and its features into context. However, for some purposes, maps can have a much more profound usefulness. I was particularly struck by this after finding a map showing the distribution of Pulmonary Tuberculosis in Edinburgh in the Bartholomew Archive Printing Record.
1,130 copies of this map were printed on the 27 April 1892, commissioned by Oliver & Boyd, an Edinburgh-based contemporary of Bartholomew. It records the location of the homes of patients admitted to the pioneering Victoria Dispensary for Consumption and Diseases of the Chest and is an uncomfortably close-to-home example of a type of map called, unsurprisingly, a disease map.
The power that can come from mapping disease has been made famous by the story of Dr. John Snow and his 1854 cholera map of Soho. Snow’s map enabled him to recognise the relationship between cases of cholera and a specific water pump on Broad Street. In turn, through this discovery, he was able to prove that cholera was a water-borne disease and not miasmatic, as many at the time believed. However, whilst this is possibly the most widely known disease map they in fact originate as early as the late 18th century, relating to yellow fever at this time.
The map is accompanied by two graphs. The first plots the number of cases against age. As can be seen, whilst tuberculosis may well have been more dangerous to vulnerable groups it is in fact amongst the healthiest groups of society that this chronic infectious disease is most prevalent, with those in their mid 20’s worst affected of all.
The second graph mysteriously plots height against the number of cases. The black line shows height, in the range of 5 ft. to 6 ft., against cases of tuberculosis and the red line compares these with patients admitted with other illnesses. Quite how this information was deemed useful is hard to say. Nevertheless, were you to put the data from these two graphs together it shows that in Edinburgh, in 1892, if you were 25 and 5ft7 you probably didn’t stand a chance.
The map is useful in presenting, in a clear way, general trends relating to the disease. The most obvious of course being geographical trends. This map shows that the more densely populated an area the higher the number of cases. So, this area of the Old Town,
is much more affected than a similar area in the New Town.
This is clear vindication for those that believed cramped and unsavoury living conditions did nought but help to generate, and then spread, infectious diseases. Although there is no doubt that Bartholomew happily printed more or less anything for anyone, especially at this time, this map would possibly have held particular resonance for their contemporary director, John George Bartholomew (1860-1920). For most of his life, John George suffered from pulmonary tuberculosis. He was often chronically fatigued and indeed, it was arguably the long-term effects of tuberculosis that led eventually to his untimely death. There is therefore just a small possibility that one of the small red spots, on this fairly small map, represents John George himself.