Tracking a nation's health can be a painstaking business. But now, a team of researchers from the University of Pittsburgh have brought together and digitized all the weekly surveillance reports of diseases in the US since 1888 into one database.
The researchers collated all weekly notifiable disease surveillance tables published between 1888 and 2013 - approximately 6,500 tables. Because of their age, many of these tables were available only in paper format or as PDF scans in online repositories that could not be read by computers and had to be hand-entered.
With an estimated 200 million keystrokes, the data - including death counts, reporting locations, time periods and diseases - were digitized. A total of 56 diseases were reported for at least some period of time during the 125-year time span, with no single disease reported continuously.
Tracing the path of epidemics
Named Project Tycho after Tycho Brahe, a 16th century nobleman whose detailed astronomical observations helped Johannes Kepler derive the laws of planetary motion, the database is free to use and is publicly available.
Dean of the Graduate School of Public Health Dr. Donald Burke explains the significance of the choice:
"Tycho Brahe's data were essential to Kepler's discovery of the laws of planetary motion. Similarly, we hope that our Project Tycho disease database will help spur new, life-saving research on patterns of epidemic infectious disease and the effects of vaccines. Open access to disease surveillance records should be standard practice, and we are working to establish this as the norm worldwide."
The database enables researchers to track the spread of diseases and also chronicle the impact that vaccines have had in controlling communicable diseases.
Dr. Burke continues:
"Historical records are a precious yet undervalued resource. As Danish philosopher Soren Kierkegaard said, we live forward but understand backward. By 'rescuing' these historical disease data and combining them into a single, open-access, computable system, we now can better understand the devastating impact of epidemic diseases, and the remarkable value of vaccines in preventing illness and death."
By overlaying the reported outbreaks with the year of vaccine licensure, the researchers are able to give a clear, visual representation of the effect that vaccines have in controlling communicable diseases.
The results showed that despite a pertussis vaccine being available since the 1920s, the largest outbreak since 1959 was recorded in the US last year. Recurrences of measles, mumps and rubella have also been noticable since the 1980s.
Lead author Dr. Willem G. van Panhuis, assistant professor of epidemiology at the university, notes:
"Using this database, we estimate that more than 100 million cases of serious childhood contagious diseases have been prevented, thanks to the introduction of vaccines. But we also are able to see a resurgence of some of these diseases in the past several decades as people forget how devastating they can be and start refusing vaccines."
Steven Buchsbaum, deputy director of Discovery and Translational Sciences for the Bill & Melinda Gates Foundation, which partly funded the research, concludes:
"We anticipate this will not only prove to be an invaluable tool permitting researchers around the globe to develop, test and validate epidemiological models, but also has the potential to serve as a model for how other organizations could make similar sets of critical public health data more broadly, publicly available."