# Case data

Georeferenced cholera case data were available for the Harare area collected by the Ministry of Health and Child Care (MoHCC) following the World Health Organization (WHO) guidelines. The first case was recorded on September 4, 2018, and the last on January 9, 2019. <mark>WHO criteria for case diagnosis state that any patient aged 5 years or more presenting with acute watery diarrhea and severe dehydration where cholera is not known to be occurring, or any patient 2 years or older presenting with acute watery diarrhea where cholera is known to be occurring can be suspected as a cholera case. Confirmation is achieved by sampling a subset of patients during the course of the epidemic.</mark><sup>2</sup> <mark>Date of diagnosis, gender, age and geo-location of the case’s dwelling are also collected.</mark> For the purpose of spatio-temporal analyses, cases were aggregated across 7-day bins from September 1, 2018. Age and gender of the patients is not taken into account in this analysis. A total of 9,890 cases were included in the analysis after cleaning.

# Population Characteristics Data

Population density data were available from Facebook HDX[27]. Small Area Estimates (SAEs) for poverty produced by the World Bank were used for ward area estimates of poverty. Household access to water, sanitation and hand washing infrastructure was taken from the DHS 2015. This was available at the cluster level for 60 clusters for Harare and the surrounding area, and 44 inside the city.

# Water and Sanitation  Infrastructure and Environment Data

Data on water and sanitation infrastructure in the city was collected from a variety of sources. The water and sanitation network shape files for the city were obtained with the support of the City of Harare’s (CoH) Water and GIS departments. Complaints data were digitized for 7,179 water network breakage reports and 24,713 sewer burst location reports from around the city with the support of Harare’s GIS department. Water quality samples for 23 sampling points, administrative boundaries for water supply (DMAs) (165 suburbs), and the location of 362 markets and public facilities were also collected and digitized by City of Harare’s GIS department. Data on 1,848 private borehole locations was provided by Manyame, Upper Mazowe and Nyagui Sub-catchment area operators, for which 1,721 were inside Harare. Finally, a groundwater vulnerability index was developed by Ziva, based on a combination of geological factors (fault index, soil permeability, depth to groundwater, topographic wetness index and fissure flow).

# Population Mobility Data

We use anonymous and aggregated call detail record (CDR) data provided by two mobile network operators in Zimbabwe covering the period of the outbreak (September 2018-February 2019). Anonymous CDR data contain information on the location of the nearest cellphone tower through which any calls or texts made or received are routed. By comparing the locations of where these

> 2 It is standard practice in epidemic response that ‘Once an outbreak is declared, there is no need to confirm all suspected cases. The clinical case definition is sufficient to monitor epidemiological trends’. [26]

4