Highlights ■ Patients gave informed consent to share GPS history from their smartphones. ■ Anonymized GPS data revealed stay points and malaria infection hotspots in Manaus. ■ Hotspots guided health agents to mosquito breeding sites,  aiding malaria control. ABSTRACT Objective: To leverage passively collected retrospective smartphone location data to accurately identify malaria transmission hotspots through the development of a novel tool, the Sickness Positioning System. Methods: We collected anonymized location history data from over 200 malaria-infected individuals using Google Takeout. […]