The 2024 Paris Summer Olympics and Paralympics Games (OPG) were held predominantly in Paris and the seven surrounding Départements of Île-de-France (IdF) Région , from 26/07 to 08/09. To contextualize epidemiological findings, we estimated population denominators, accounting for vacationers’ departures and visitors’ arrivals. We used daily population estimates produced by a specialized mobile phone company, modelled using antennae-mobile phone connection data (MPD). These were available for the period 01/06-30/09 and for each IdF Département , detailing the provenance in France or 180 other countries or territories of the SIM card registration, regardless of the telephone operator. A total of 493,368,201 person-days were documented in IdF during the 45-day OPG surveillance period. Of these, 63.9% were attributed to IdF residents of any nationality, 12.8% to French non-IdF residents, 8.2% to non-French EU/UK/Swiss and 15.1% to non-EU/UK/Swiss residents. Over the entire Summer, the estimated daily IdF resident population in IdF went from a maximum of 10,636,392 on 04/06 to a minimum of 5,709,363 on 17/08 (-46.3% of baseline). Visitors from outside EU/UK/Swiss of any nationality went from a maximum of 1,834,441 on 02/08 to a minimum of 1,467,726 on 01/09. MPD-based population estimates were used to contextualize the end-of-summer rise in indicators and estimate the number of visitors from epidemic countries when influenza A virus was detected or Mpox was declared an international emergency in August, 2024. Near-real-time, MPD-based population estimates were used as denominators to effectively and usefully interpret epidemiological indicators in the 2024 summer and OPG period during which the IdF population was highly diverse and mobile. This approach is a legacy of the 2024 OPG and should be instituted routinely.
Pascal et al. (Wed,) studied this question.