Tracking infectious disease outbreaks with satellite images of the nighttime sky

Researchers at Princeton are developing an unconventional way to use satellite images of nighttime lights to monitor seasonal population migration patterns and potentially pinpointing disease hotspots in developing nations. CNet reports:

Using nighttime images taken of Niger’s three largest cities between 2000 and 2004 by a U.S. Department of Defense satellite, and checking those images against public health records compiled by Niger’s Ministry of Health, [researchers] saw that new measles cases clearly occurred in the brightest areas.

…The team began formulating the idea when [lead author and postdoctoral researcher Nita Bharti] and colleagues published a paper in 2010 finding that measles epidemics most often occur during Niger’s dry season, when many farmers migrate to urban centers. The severity of outbreak, they concluded, must be linked to shifts in population density, not lower rainfall or other environmental factors. Without being able to measure these population changes, though, they were stuck with an untested hypothesis.

After using spacial analysis software ArcGIS and ERDAS Imagine, the team was not only able to confirm their suspicions but is also now looking into joining the night light technique with other population trackers-such as cell phone usage-in an attempt to get the most accurate data possible.

The study is an example of how more researchers are finding ways to use satellite data to gain new insights into the relationship between land, humans and disease transmission. In a recent study, researchers at Stanford combined images from orbiting satellites with information obtained from door-to-door interviews to better understand the spread of parasitic diseases.

Previously: Stanford researchers examine parasitic diseases using satellite data