U. FLORIDA (US) — Phone calls and text messages from 15 million mobile phones may help track the spread of malaria in sub-Saharan Africa, new research shows.
Mosquitoes that carry malaria have a limited flight range, but that doesn’t stop the disease from traveling long distance—people infected can carry it anywhere a car or plane can reach.
Eliminating it can be challenging, because available resources for health care and mosquito control are limited and need to cover a large geographic region. In Kenya, researchers are using cell phone records to identify which regions should be targeted first to maximize the benefit of control and elimination efforts.
“Over 30 countries around the world have stated a national goal of eliminating malaria,” says Andy Tatem, associate professor of geography at the Emerging Pathogens Institute at the University of Florida and a co-author of the study that is published in the journal Science.
“But it’s difficult to eliminate the disease when new cases are constantly being imported.”
It is also impossible to pin down how a disease is spreading without accurate information about where people live, says senior author Caroline Buckee, assistant professor of epidemiology at the Harvard University School of Public Health. “Figuring out where people live sounds trivial, but it’s actually a very difficult thing to do in sub-Saharan Africa.”
Tatem provided the needed population maps through the AfriPop Project that uses satellite imagery, census data, and land cover maps to create detailed population distribution maps of sub-Saharan Africa.
The team then used records provided by a Kenyan cell phone company to identify popular travel routes between population centers. The records gave the team a year’s worth of data on 15 million anonymous cell phone users’ movements around Kenya.
“Researchers have used GPS trackers, surveys, and traffic flow on highways to try to understand how people are moving, but that gave us information about a few hundred people at best,” Buckee says. “Using cell phone records gave us billions of data points.”
The next step was to apply the population and movement information to a simple malaria transmission model that predicts risks of infection using probability mathematics. The result was a new map that shows how malaria is most likely to move between different regions in Kenya and which locations, if targeted for malaria control or elimination, would yield the biggest benefit nationally.
“Malaria control programs have very effective tools today to prevent transmission, but unfortunately, resources for implementing them are quite constrained,” says Justin Cohen, the senior technical adviser from the Clinton Health Access Initiative Malaria Control Team.
“The technique used in this study gives us a way to optimize the impact of our limited resources.”
Source: University of Florida