Please refer to the attached file.
Since the publication of the first version of this report, a number of health zones which then had no confirmed cases, but were listed in the report as at very high risk, now have confirmed cases. This strengthens the argument for prioritising areas high on the list (Table 1 and Annex A) for surveillance activities. Among the top ten recipient health zones, only two have not yet had confirmed cases as of 1 June (Tchomia, ranked 6th, and Drodro, 9th, both in Ituri), and among the top twenty health zones only six have yet to confirm cases.
This report provides data on travel patterns out of Bunia, Mongbwalu and Rwampara health zones. These health zones have seen the vast majority of confirmed and suspected cases and therefore currently confer the largest known exportation risk to other health zones. Additional analyses and data releases are planned.
The data is based on anonymised data on the movements of hundreds of thousands of subscribers on the Vodacom Congo (DRC) network in Ituri. Further details on methods and analytical choices are provided in the methods section.
We follow the movements of all anonymised subscribers who were registered at least once in any of the three health zones of Bunia, Mongbwalu and Rwampara during the three weeks immediately preceding the death of the presumed index case on 24 April 2026. We then follow their movements out of the three health zones.
We compute, at successive days from the end of the reference period at 23 April (+1 day, +7 days, etc.), how many cohort members have been observed in each health zone, capturing the progressive spread of the study cohort day by day (Fig. 1 and Table 1). Each subscriber is counted in a health zone from the first day they are observed there, regardless of how many times they appear subsequently in that health zone. A subscriber observed in multiple health zones is counted in each of those health zones.