{"id":13818,"date":"2020-02-23T20:56:03","date_gmt":"2020-02-23T20:56:03","guid":{"rendered":"http:\/\/evaggelatos.com\/?p=13818"},"modified":"2020-02-23T21:24:50","modified_gmt":"2020-02-23T21:24:50","slug":"how-we-map-epidemics","status":"publish","type":"post","link":"https:\/\/evaggelatos.com\/?p=13818","title":{"rendered":"How We Map Epidemics?"},"content":{"rendered":"

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Cartographers are mapping the coronavirus in more sophisticated ways than past epidemics. But visualizing outbreaks dates back to cholera and yellow fever.<\/h2>\n
As coronavirus cases multiply, interactive maps are helping us understand the spread of the disease\u2014and panic about it.One of the best examples is the dashboard<\/a> built by Johns Hopkins University\u2019s Center for Systems Science and Engineering with a striking red-on-black design. Using tools from mapping software company Esri<\/a>, Johns Hopkins aggregates data from health officials worldwide in real time.<\/strong> The bigger a red bubble gets, the more cases are identified in a given geographical area. The death toll from the outbreak topped 1,000 this week, making it more deadly than the 2003 SARS epidemic<\/a>.<\/p>\n
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The online dashboard Johns Hopkins built to track the 2019-nCoV outbreak had racked up 52 million views as of Jan. 31, according to Esri.<\/figcaption><\/figure>\n

Metabiota<\/a>, a company specializing in pandemic threat management, added the coronavirus to its list of over 130 pathogens it is already tracking globally.<\/a> The resulting map uses a tamer color palette\u2014except for the blinking orange dots that signal the presence of the virus in a country.<\/p>\n

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Metabiota structures data from multiple health organizations to track ongoing epidemics. It has also on-boarded and cleaned information about thousands of previous outbreaks. (Metabiota, Epidemic Tracker<\/a>)<\/figcaption><\/figure>\n

But is this really new?<\/p>\n<\/section>\n

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Spatially visualizing outbreaks goes back ages: There have been attempts at doing so since the 17th century. But in the past decades, medical cartography has taken off and democratized because of technological advances made possible by computers. On top of increasingly powerful devices, the internet enables rapid access to data-gathering and sharing.For centuries, geographers and health-care officials have used so-called geographic information systems (GIS) mapping to craft theories<\/a> on why a particular outbreak occurred based on the clustering of casualties. Now they can also project how an ongoing epidemic might evolve\u2014in real time\u2014and set policy based on those models.\u201cThe underlying goal of using a GIS in the past was to develop a greater understanding of what happened, and of some of the root causes,\u201d said Este Geraghty, chief medical officer and health solutions director at Esri. \u201cBut today, GIS has evolved, so we can do so much more.\u201d<\/p>\n

Maps in the time of cholera<\/strong><\/h4>\n
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In the earliest documented disease map, Fillipo Arrieta visualized the strategy for containing the spread of disease in the region of Bari, Italy 1690-92. (Controlling the Geographical Spread of Infectious Disease: Plague in Italy, 1347-1851<\/a>)<\/em><\/figcaption><\/figure>\n

The first occurrence of disease mapping can be traced back to 1692, according to Tom Koch, professor of geography at the University of British Columbia and author of the book Cartographies of Diseases<\/u><\/a><\/em>. At the time, plague was wreaking havoc throughout Europe, and Fillippo Arrieta, an Italian royal auditor, spatially visualized the strategy<\/a> for containing the spread of the disease in the region of Bari, Italy. On Arrieta\u2019s map, Bari is separated from the rest of the country by a dashed line that represents a \u201ccordon sanitaire.\u201d Within the cordoned-off province are two smaller areas, separated from the rest by a thicker line. The observant reader can see large \u201cD\u201d letters in the top right area, meaning that the province is infected by the plague.<\/p>\n<\/section>\n

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However, according to Koch\u2019s research<\/a>, the first truly detailed spatial study of an epidemic did not appear before 1797 (approximately) and the publication in the Medical Repository<\/em> of Valentine Seaman\u2019s maps of the yellow fever outbreak in New York City. Seaman overlaid<\/a> the location of yellow fever cases\u2014 dots on the map below\u2014with the position of\u00a0 dumping areas and sewage sites in lower Manhattan. He marked these sites with a thick letter \u201cS.\u201d Reflecting upon his observations, Seaman concluded that the deadly outbreak was linked to those areas and their putrid emanations.<\/p>\n
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Valentine Seaman, An Inquiry Into the Cause of the Prevalence of the Yellow Fever in New York, in the Medical Repository, 1797. (Brian Altonen<\/a>)<\/figcaption><\/figure>\n

Even if Seaman\u2019s theory was not quite right\u2014yellow fever is carried by the mosquitoes that were breeding in these waste sites\u2014disease mapping was born. Over time, technology improved and disease-related data became more available, according to Koch. However, it was only when an epidemic of cholera massively hit Europe, and especially the U.K., in the mid-19th century that disease maps exploded.<\/p>\n