Inaccurate Maps of the Ebola Virus Outbreak

World Health Organization

The Atlantic’s Ed Yong looks at a problem in the public health response to this month’s Ebola virus outbreak in the Democratic Republic of Congo: inaccurate maps of the areas affected by the virus.

On Thursday, the World Health Organization released a map showing parts of the Democratic Republic of the Congo that are currently being affected by Ebola. The map showed four cases in Wangata, one of three “health zones” in the large city of Mbandaka. Wangata, according to the map, lies north of the main city, in a forested area on the other side of a river.

That is not where Wangata is.

“It’s actually here, in the middle of Mbandaka city,” says Cyrus Sinai, indicating a region about 8 miles farther south, on a screen that he shares with me over Skype.

Almost all the maps of the outbreak zone that have thus far been released contain mistakes of this kind. Different health organizations all seem to use their own maps, most of which contain significant discrepancies. Things are roughly in the right place, but their exact positions can be off by miles, as can the boundaries between different regions. […]

To be clear, there’s no evidence that these problems are hampering the response to the current outbreak. It’s not like doctors are showing up in the middle of the forest, wondering why they’re in the wrong place. “Everyone on the ground knows where the health zones start and end,” says Sinai. “I don’t think this will make or break the response. But you surely want the most accurate data.”

The WHO map in question, reproduced at the top of this post, can be found here. See Virology Down Under’s roundup of maps put out by the various NGOs, which the Atlantic article refers to.

Predicting Future Malaria Outbreaks from Satellite Data

Data from NASA’s earth-observing satellites is being used to predict future malaria outbreaks in the Amazon rainforests of Peru. To be sure, as the above video shows, this is really about taking geospatial and remote sensing data from several different sources and correlating them to build a predictive model: it’s John Snow’s cholera map at large scale and for the satellite age.

Mapping the Zika Virus (and the Problems with Doing So)

Maps about the Zika virus have been cropping up lately. I’ve been reluctant to post them, initially because I didn’t want to play a role in whipping up unnecessary panic, but also because—the more I looked at them—many of the maps are problematic in and of themselves.

Some, like this CDC map of countries with active Zika virus transmission, lack useful detail. Or if they have detail, it’s not at all helpful: The Economist’s map shows the local risk of transmission and the number of travellers from Brazil; this map aggregates news stories about the virus and overlays the predicted distribution—predicted, mind—of two mosquito species. Neither map says anything about the spread of the virus itself; both could do a great job of scaring the crap out of anyone who gives either map a casual look. Finally, like these Scientific American maps, they can be extremely U.S.-centric, suggesting that the virus is only a problem insofar as it affects us. [via]

Update, 4 February: Direct Relief’s Zika virus maps, some of which taken from the above, share the problem of indirectness but lose the U.S.-centricity. [via]