Noting the WHO on Wednesday released its 2013 World Malaria Report, Marketplace examines how an epidemiologist at Harvard is using cell phones to track the disease in Africa by “plotting malaria cases on a map and then overlaying data showing where people are moving, which helps make better predictions about where the disease might go next.” The news service writes, “‘The challenges are the very poorest populations, and that the density of cell towers determines how high a resolution you can get your estimates,’ Buckee says. ‘So, in some of the most rural and underserved populations, we have the hardest time'” (Johnson, 12/11).