(2022-12-08) Haïti, épidémie de choléra 2022, rapport n° 6

Haiti | 2022 Cholera outbreak Report #6 08 December 2022 Population movements from cholera-affected areas in Port-au-Prince and identification of communes at potentially increased risk of new outbreaks: Situation as of 07 December Executive summary Our research1 on the 2010 cholera outbreak showed that mobility indicators derived from aggregated and anonymised Call Detail Records (CDRs) were predictive (with uncertainty) of the geographic spread of the epidemic. Here, we show mobility patterns from the Port-au-Prince metropolitan area relevant to the ongoing outbreak and replicate our analyses to identify areas potentially at increased risk of new outbreaks. In combination with other evidence, this can help identify areas to be prioritised for surveillance and interventions. Most trips are short-distance. Travel from the Port-au-Prince metropolitan area, where there are high numbers of suspected cases, is concentrated in nearby communes in the Ouest department but longer trips are also observed, particularly to the Nippes and Sud departments (Map 1). Our modelling of the estimated flows of infectious persons (Map 2) shows the frontier of the epidemic has continued to move and more areas now experience increased infectious pressure. Map 2 highlights communes across Haiti as areas at potentially increased risk of new outbreaks. Among communes with no confirmed cases in the past 30 days, infectious pressure is most elevated in Nippes and Sud departments but is also substantially elevated in communes in Nord, Centre and Artibonite departments. We also show that geographic proximity to communes with confirmed cases alone may not equate to higher risk of new outbreaks. However, our methods may overestimate risk in areas along major travel corridors (e.g. highways). The analyses have limitations and should be used in conjunction with other available evidence (see Considerations). We welcome feedback from responders to help us improve future reports and any requests for specific analyses. As new areas acquire local transmission, the risks shown in this report will change and we aim to update the analyses. Where are people in cholera-affected areas of Port-au-Prince metropolitan area travelling to? Flows of subscribers from communes most affected by cholera and lying within the Port-auPrince metropolitan area The background of Map 1 (right) shows the number of suspected cases of cholera in the past 7 days (29 Nov. – 05 Dec.) across Haiti, calculated from reports by the Ministry of Public Health and Population (MSPP). The lines indicate our estimate of the largest flows of subscribers from these cholera-affected communes within the Port-au-Prince metropolitan area to other communes across Haiti. We used CDR data from the 05 November to 05 December 2021 (see Data section for more information) to estimate the flows of people travelling from communes in the Port-au-Prince metropolitan area in which there have been more than 50 confirmed cholera cases reported (highlighted area) in the past 30 days (05 Nov – 05 Dec. 2022). Travel from the most cholera-affected areas of Port-au-Prince is mostly short distance within the Ouest department, but there are a smaller number of longer trips, including to communes in the Sud, Nippes and Artibonite departments. These mobility patterns remain consistent with our previous reports. Table 1 (page 3) ranks the communes receiving the greatest flows of subscribers from communes within the Port-au-Prince metropolitan area, according to the estimated number of incoming subscribers. Contact us: info@flowminder.org @Flowminder Map 1 Which areas are at potentially increased risk of new outbreaks of cholera? Map 2 Estimated infectious pressure on communes with no recent confirmed cases Infectious pressure is an indicator describing broadly the estimated daily number of incoming infectious persons to each commune, over the 7 days from 29 November to 05 December 2022. Our previous research1 shows that this indicator is predictive (with uncertainty) of new outbreaks in the coming 7 days for areas with no known outbreak. Map 2 (right) shows the normalised infectious pressure for each commune as of 07 December 2022 (rescaled between 0 and 1), with greater infectious pressure associated with greater risk. We estimate this from the flows of subscribers between areas and the number of suspected cases reported by MSPP. The frontier of the outbreak has continued to advance and more areas have an elevated infectious pressure. Amongst communes with no confirmed cases in the last 30 days, infectious pressure is highest in communes in the Nippes and Sud departments. However, compared to previous reports, infectious pressure is more evenly spread across the country and is also substantially elevated in Nord, Centre and Artibonite departments. Table 2 (page 3) lists the communes with no confirmed cases in the past month, which experience the greatest infectious pressure (indicative of increased risk of new outbreaks). Note: Infectious pressure is an indicator of risk of new outbreaks originating from people coming into a commune. For communes with ongoing transmission, including those with no confirmed cases, the highest risk of continued spread will likely stem from the ongoing transmission within those communes, and not from the infectious pressure shown on Map 2. About this report Data Methodology The analyses in this report use Call Detail Records (CDRs) provided by Digicel Haiti. Cholera case data are provided by Ministry of Public Health and Population of Haiti. For more information, please click here. For information on how these indicators were calculated, please click here. Data considerations The estimates shown are our best current assessment of movements. However, there are a number of uncertainties. The information should be interpreted together with other available evidence. For more information, please click here. Contact us: info@flowminder.org @Flowminder Privacy No personal data, such as an individual’s identity, demographics, location, contacts or movements, is made available to the government or any other third party at any time. All results are fully anonymised and our methodologies comply with the European Union’s General Data Protection Regulation (EU GDPR 2016/679). For more information please click here. We welcome feedback to help us improve future reports and requests for specific types of analysis This is the final weekly report that we currently have planned but please email info@flowminder.org with any feedback and suggestions, or if you have any specific analytical requirements we can support. References 1 Bengtsson, L., Gaudart, J., Lu, X., Moore, S., Wetter, E., Sallah, K., Rebaudet, S. and Piarroux, R., 2015. Using mobile phone data to predict the spatial spread of cholera. Scientific reports, 5(1), pp.1-5. Table 1 Table 2 Communes receiving the greatest flows of subscribers from communes within the Port-au-Prince metropolitan area where there are substantial confirmed cholera cases (highlighted area, Map 1). Communes with no confirmed cholera cases in the last month (05 November - 05 December 2022) which experience the highest infectious pressure. Higher infectious pressure is associated with an increased risk of new cholera outbreaks. Ranking Commune Departement Normalised Flow Ranking Commune Departement Normalised infectious pressure 1 Tabarre Ouest 1 1 Petite Rivière de Nippes Nippes 1 2 Croix-Des-Bouquets Ouest 0.6 2 Aquin Sud 0.9 3 Kenscoff Ouest 0.2 3 Arnaud Nippes 0.9 4 Gressier Ouest 0.1 4 Miragoâne Nippes 0.7 5 Cabaret Ouest 0.1 5 Anse-à-Veau Nippes 0.5 6 Léogâne Ouest 0.08 6 Cap-Haïtien Nord 0.5 7 Thomazeau Ouest 0.04 7 Thomonde Centre 0.4 8 Arcahaie Ouest 0.04 8 Fonds des Nègres Nippes 0.4 9 Petit-Goâve Ouest 0.03 9 Petite Rivière de l’Artibonite Artibonite 0.4 10 Miragoâne Nippes 0.03 10 Arcahaie Ouest 0.3 This report and its contents may only be shared with attribution to the Flowminder Foundation and Digicel Haiti. Adaptation is permitted as long as the changes are indicated and the Flowminder Foundation and Digicel Haiti are cited. Use of the report and its contents is limited to humanitarian and development purposes. Disclaimer of Warranties and Limitation of Liability: To the extent possible, Flowminder and Digicel offer this report and its contents as-is and as-available, and make no representations or warranties of any kind concerning this report and its contents, whether express, implied, statutory, or other. This includes, without limitation, warranties of title, merchantability, fitness for a particular purpose, non-infringement, absence of latent or other defects, accuracy, or the presence or absence of errors, whether or not known or discoverable. To the extent possible, in no event will Flowminder or Digicel be liable on any legal theory (including, without limitation, negligence) or otherwise for any direct, special, indirect, incidental, consequential, punitive, exemplary, or other losses, costs, expenses, or damages arising out of the use of the report or its contents, even if Flowminder or Digicel have been advised of the possibility of such losses, costs, expenses, or damages. The disclaimer of warranties and limitation of liability provided above shall be interpreted in a manner that, to the extent possible, most closely approximates an absolute disclaimer and waiver of all liability. Contact us: info@flowminder.org @Flowminder Acknowledgements This group of cholera outbreak reports has been made possible thanks to the pseudonymised Call Detail Records (CDR data) provided by Digicel Haiti on the Flowminder Foundation server hosted behind Digicel Haiti firewalls in Port-au-Prince, Haiti. The cholera case data used for the reports are from Haiti’s Directorate of Epidemiology Laboratory and Research (DELR). This work was funded by the International Organization for Migration (IOM), thanks to funding received by IOM from the Centers for Disease Control and Prevention (CDC). This work has also been possible thanks to funding by the Agence Française de Développement and the William and Flora Hewlett Foundation who support current Flowminder's activities in Haiti, where Flowminder focuses on enabling the increased access to and use of mobile operator data in ways that are ethically sound, financially viable, and sustainable. Contact us: info@flowminder.org @Flowminder