Researchers with the Harvard School of Public Health and seven other institutions used cell phone data from the mobile phone provider Safaricom to understand the regional incidence of malaria in Kenya and how human travel patterns impacted its spread. The 2012 study, which appeared in the journal *Science*, mapped every call or text made by 14,816,521 Kenyan mobile phone subscribers. The project also leverages a malaria prevalence map developed by the Kenya Medical Research Institute (KEMRI) and the Malaria Atlas Project to make an estimation of disease prevalence and probability of infection in residents and visitors of an area. From this analysis, researchers found malaria largely eminated from Kenya's Lake Victoria region and spread east. Researchers hope the analysis can improve understanding of the disease's spread and attempts to mitigate it.