Inferring Snails by Satellite
In the project’s early days, the research team had tried to sketch out schistosomiasis transmission patterns using relatively low-quality satellite images. But the maps were too fuzzy to correlate individual pixels with the kinds of details they were finding through their surveys on the ground.
Chamberlin, who has become an expert in applying machine learning to disease ecology, flew mapping missions by drone to bridge this gap, capturing high-quality images of water access points in which individual vegetation types could be discerned; the researchers knew that particular vegetation types, in turn, predict higher schistosomiasis infection rates year after year.
“We were able to extrapolate what we know from really fine-scale field work to these larger drone images with a high degree of accuracy,” Chamberlin says. “And then we could use that to evaluate satellite imagery over the same time period and a much broader area, which enabled us to do more regional-scale analysis and monitoring.”
The linchpin in the research, supported by the initial HAI grant, came from Liu and Bauer: A set of machine learning tools that stitched together these three streams of information, ultimately providing a picture of potential infection hotspots.
The methodology today can be used both to monitor populations for rates of schistosomiasis and to prioritize public health outreach in populations that are at risk of exposure.