This is kinda cool, as a possible means to track human migration and perhaps infectious disease risk — satellite tracking of light emissions.
The disease outbreak idea here seems like a bit of a stretch, I have to say.
What these researchers are tracking are population levels based on light output. From the population density, they infer the risk of disease outbreaks. I would think a more reliable diagnosis will still be best obtained by health workers on the ground. But who knows? Read for yourself.
From Princteon University:
Princeton University-led researchers report in the journal Science Dec. 9 that nighttime-lights imagery presents a new tool for pinpointing disease hotspots in developing nations by revealing the population boom that typically coincides with seasonal epidemics. In urban areas with migratory populations, the images can indicate where people are clustering by capturing the expansion and increasing brightness of lighted areas. The researchers found the technique accurately indicates fluctuations in population density — and thus the risk of epidemic — that can elude current methods of monitoring outbreaks.