Mobile phone data tracks Ebola spread in Congo for first time

Health officials fighting the Ebola outbreak in eastern Democratic Republic of Congo have begun using anonymized mobile phone data to map population movements and predict where the virus could appear next — a technique never before deployed in an Ebola response. The World Health Organization and Swedish non-profit Flowminder described the effort on Wednesday.reuters+1

The approach comes as authorities struggle to contain what the WHO has called the fastest-growing Ebola outbreak on record. More than 6,250 people have been infected and 3,039 have died since the outbreak was declared on May 15, according to Congolese government data as of September 1.cdc+1

How the Tracking Works

Flowminder receives aggregated, anonymized records generated when mobile phones connect to network antennas operated by Vodacom, Congo's largest telecommunications provider, which supplies the data free of charge. Researchers use those records to estimate how populations travel between different areas, producing what Flowminder founder Linus Bengtsson described as "a predictor of how infectious people move."reuters

Traditional risk assessments assume a virus spreads outward to surrounding areas. The mobility data reveals which places are actually connected by travel patterns, even if geographically distant. "It gives us a more nuanced understanding of risk," said Olivier Le Polain, head of epidemiology and analytics for the WHO Health Emergencies Programme, citing heavy population movements in Ituri province driven by mining and trade.medicaldaily+1

Early Results and the Kinshasa Risk

Flowminder's first analysis, published in early June, tracked where people who had spent time in the three initial outbreak areas — Bunia, Mongbwalu, and Rwampara — later traveled. By the end of June, all 10 destinations receiving the largest flows of travelers from those areas had reported confirmed Ebola cases.flowminder+1

The method drew particular attention to Kisangani, a major transport hub on the Congo River connecting eastern and western Congo. Le Polain said the data showed by mid-June that the outbreak could reach Kisangani faster than initially expected, and operations were strengthened before the first cases were detected there.reuters+1

More recent analyses have flagged links between Kisangani and Kinshasa, Congo's capital. Fifteen of the 50 areas most connected to Kisangani were in Kinshasa province. In a modeling exercise presented in late June, the WHO estimated a 70 percent probability of a case being detected in Kinshasa by the end of September.who+1

Gaps in Coverage

The method has clear limitations. It draws only on Congolese networks, providing a partial picture of cross-border movement — precisely where the risk of international spread is highest. It also relies on a single operator; Vodacom holds a market share of nearly 35 percent, leaving movements on rival networks invisible to the analysis. Flowminder and U.N. officials say efforts are underway to secure agreements with additional operators.reuters+1

The outbreak, Congo's 17th, is caused by the Bundibugyo species of Ebola, for which no approved vaccines or treatments exist — a critical difference from previous outbreaks driven by the Zaire species.doctorswithoutborders+1