Establishing an early warning event management system at Africa CDC

Abstract

Africa is home to hotspots of disease emergence and re-emergence. To adequately detect and respond to these health threats, early warning systems inclusive of event-based surveillance (EBS) are needed. However, data systems to manage these events are not readily available. In 2020, Africa Centres for Disease Control and Prevention developed an event management system (EMS) to meet this need. The district health information software (DHIS2), which is free and open-source software was identified as the platform for the EMS because it can support data capture and analysis and monitor and report events. The EMS was created through a collaborative and iterative prototyping process that included modifying key DHIS2 applications like Tracker Capture. Africa CDC started piloting the EMS with both signal and event data entry in June 2020. By December 2022, 416 events were captured and over 140 weekly reports, including 19 COVID-19 specific reports, were generated and distributed to inform continental awareness and response efforts. Most events detected directly impacted humans (69%), were considered moderate (50%) to high (29%) risk level and reflected both emerging and endemic infectious disease outbreaks. Highly pathogenic avian influenza, specifically H5N1, was the most frequently detected animal event and storms and flooding were most frequently detected environmental events. Both data completeness and timeliness improved over time. Country-level interest and utility resulted in four African countries adapting the EMS in 2022 and two more in 2023. This system demonstrates how integrating digital technology into health systems and utilising existing digital platforms like DHIS2 can improve early warning at the continental and country level by improving EBS workflow.

Fig 1. Timeline of key Africa CDC Event Management System development milestones, December 2019 to December 2023.

Fig 2. Event-based surveillance workflow and process in relation to the Africa CDC Event Management System.

Figure description: 1. Signals and events occurring in Africa are detected by Africa CDC staff through media scanning efforts including the use of media aggregators like EIOS and social media like WhatsApp chat groups. Relevant EWAR information detected on EIOS is pinned to a specific board within EIOS for direct import into the Africa CDC event management system (EMS) via the EIOS/EMS Importer application. Signals are created within the EMS from imported articles. Information detected by other means is directly entered into the EMS via the Tracker Capture application. 2. Signals detected are triaged to ensure no duplicate reports are entered and that those entered meet IHR and Africa CDC EWAR criteria. Signals not fulfilling the triage criteria are closed out and discarded in the EMS using the Tracker Capture application. 3. Signals undergo a verification process by consulting official sources including any reports made by the local government. Once verified, a signal is changed to an event within the EMS and the date and source of the verification is documented in the Tracker Capture application. 4. All events undergo risk assessment and characterization by staff using the Africa CDC risk algorithm (see Africa CDC EBS Framework Chapter 1, Fig 4) (13). Responses to the risk algorithm questions and the date associated with the risk assessment are entered into the Tracker Capture application. The EMS automatically determines the risk level; however, staff have the option to override this determination by providing a justification statement. Risk assessment can be periodically updated as new information is received. 5. Based on the risk level of an event, an automated alert is sent to key Africa CDC staff and EMS users via email to inform them of this event for any actions that need to take place. Weekly reports are also generated within the Standard Report application, exported, and then distributed (21) by Africa CDC staff to all stakeholders. Data entered can be analysed and visualised (e.g., dashboards, graphs, charts, maps, etc.) within the EMS through the Data Visualizer, Dashboard, Maps, Standard Reports and Event Visualiser applications. Additionally, EMS data can also be exported in CSV, CVS or XLS, JSON, HTML, and XML formats to feed external data visualisation applications. Routine monitoring, review, and updating of active signals and events is supported by the Africa CDC Event Tracking Tool with updates being made through the Tracker Capture application. Additionally, monitoring and evaluation of data accuracy and quality (not shown in figure) is supported with the use of the Event Reports, Line Listing, Standard Reports and Dashboard applications.