The analysis is carried out by the Swedish non‑profit Flowminder, which turns the anonymous records generated when phones connect to network antennas into estimates of how people travel between different regions.

Vodacom, Congo’s largest mobile operator, provides the data free of charge. Flowminder says it receives only aggregated and anonymized records, so no individual subscriber can be identified.

This technique has never been applied in an Ebola response before, marking a shift from traditional risk assessments that focus solely on nearby hotspots.

Flowminder’s early model highlighted a significant risk to Kisangani, a major transport hub, before any cases were reported there. Olivier Le Polain, head of epidemiology and analytics for response at the WHO Health Emergencies Programme, said the data prompted the agency to strengthen operations in the city ahead of the first detections.

By revealing hidden travel links, the phone‑data approach lets authorities direct limited surveillance and treatment resources to the places most likely to see new infections.