John Snow's mapping of the Broad Street Pump cholera outbreak
BY DAVID BISHAI, PROFESSOR, JOHNS HOPKINS BLOOMBERG SCHOOL OF PUBLIC HEALTH
We all know the story of John Snow and the Broad Street pump. During the 1854 cholera epidemic in London Dr. Snow painstakingly produced a map of the cases and determined that the infamous pump was the origin of the outbreak. He used his evidence to persuade city officials and the pump handle was removed terminating the epidemic.
Now consider the counterfactual. Suppose the good doctor had taken an online course on global health systems a few months before the outbreak. Dr. Snow’s data would have been an excel spreadsheet repeatedly forwarded until it reached the desk of a global disease burden specialist. Disibility Adjusted Life Years (DALYs) lost would be calculated. Tree diagrams would be produced. The incremental cost-effectiveness ratio of various strategies would be tabulated. With luck, the evidence would be sufficient to host a global summit at which donors would pledge millions to launch a “Decade of Action” against cholera. With much fanfare a fleet of carriages emblazoned with “The Cholera Project” and a highly vetted logo would be parked next to project headquarters ready to avert cholera DALYS across the globe. No doubt there would be a research institute to develop biomedical solutions — an amazing vaccine, or special rehydration liquid that would require an army of doctors, nurses, and health workers to aid the stricken. John Snow would be promoted to head the corps of do-gooders, and his picture would be featured prominently in The Lancet as a global health hero.
Nightmare over. History did not turn out that way—at least not for 19th century England. Fortunately due to an enlightenment era faith in the responsibility and capacity of local government to improve the wellbeing of humanity, the people of England institutionalized the local solution of local public health problems. Despite tremendous economic growth in the 19th century, health in the UK did not improve until the English invented public health. More money was not enough to improve health and life expectancy did not top 40 years until 1870. Throughout the 1840s, 50s, and 60s England passed a series of laws that created local health boards, empowered local health officers, and developed local health codes that could be locally enforced. Political resistance to health reforms occurred locally and was overcome locally. Public health reforms prevailed with much more success after voting reforms in 1867 enfranchised the working men whose families stood to gain the most from transforming pestilent crowded slums into livable cities. The John Snow strategy worked and England’s life expectancy began to climb from 40 years in 1867 to 65 by 1945 — before antibiotics and most modern 'cures' were discovered. Other countries around the world had the same success with the same strategy. Prior to the 1950s, economic growth alone wouldn’t bump a country’s health statistics; doctors and universal coverage offered weak remedies. Public health strategies helped translate growing prosperity into hygienic living conditions and this was the route to good health. It still is.
This week the world will gather at the 2nd Global Symposium on Health Systems Research in Beijing meeting to collectively forget everything that John Snow stood for. Almost all the programming is about improving the delivery and financing of medical services. Attendees will forget that the best solutions are local solutions based on local data used by local health advocates in harmony with their local community. Few presenters seem to notice that the best and most important part of any health system is not the gleaming hospitals and ICUs. The part that of the health system that creates health changes the social and physical determinants of health through good old fashioned public health practice. Most participants are content to sway to the siren’s song of universal coverage and pretend that doctors are the solution to every malady.
James Joyce speaks in Ulysses of the “ineluctable modality of the visible” – what can be seen with the eye becomes the mode and draws our mind with no escape. The unseen forces in the world may be much more powerful than the visible, but even the most well-intentioned and wise will be drawn to what they can see. The whole world sees doctors and nurses so deploying them and fixing their business problems has become the business of global health. Public health officers stay out of sight by preventing problems before they occur. Who has ever seen a public health officer? What Broad Street survivor would recognize or remember that their life was saved by John Snow?
The good news is that at least one woman in Beijing remembers John Snow. Dr. Afisah Zakariah is Director of Policy, Planning, Monitoring, and Evaluation for the Ministry of Health in Ghana. At the Thursday session of the conference she described Ghana’s plans to strengthen its essential public health functions. Building on a World Bank measurement tool, Ghana will audit the performance of district health management teams. The audits will give each district health official a same-day report card and form a foundation for a personalized performance improvement plan with regular follow up coaching visits. The essential public health functions that will be graded and improved in Ghana are the essence of what John Snow did on Broad Street — collecting and using local surveillance data, mobilizing the community around the data, and collaboratively implementing local public health measures. Lucky for Ghana that Dr. Zakariah is on board. This is potentially lucky for Dr. Zakariah’s audience. Maybe they won’t forget John Snow and the spirit of 1854.