The Looming Threat of Dengue Fever: The Africa Context.

In Africa, compared to 2019, dengue infections have surged ninefold by December 2023, with over 270 000 cases and 753 deaths reported across 18 African Union (AU) Member States. This commentary synthesises the context of dengue outbreaks in Africa and provides recommendations for sustainable control. In 2023, 18 African Union Member States reported outbreaks of dengue, among which seven had ongoing armed conflicts. These countries were amongst the top 15 African countries contributing to the most displaced persons on the continent and accounted for 98% of all dengue cases reported in the continent in 2023. Climate change remains an important driver, both through the displacement of people and global warming. The continent continues to face several challenges in detection, reporting and management, such as the lack of local laboratory capacity, misclassification of dengue cases and lack of medical countermeasures. Solutions targeting the strengthening of cross-border surveillance and early warning systems using a multisectoral one-health approach, local research and development for therapeutics and diagnostics and community engagement empowering communities to protect themselves and understand the gravity of the threat could help curb the spread of the disease in Africa.

Establishing an early warning event management system at Africa CDC.

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.

Evaluation of cholera surveillance systems in Africa: a systematic review.

Introduction: Despite several interventions on the control of cholera, it still remains a significant public health problem in Africa. According to the World Health Organization, 251,549 cases and 4,180 deaths (CFR: 2.9%) were reported from 19 African countries in 2023. Tools exist to enhance the surveillance of cholera but there is limited evidence on their deployment and application. There is limited evidence on the harmonization of the deployment of tools for the evaluation of cholera surveillance. We systematically reviewed available literature on the deployment of these tools in the evaluation of surveillance systems in Africa. Method: Three electronic databases (PubMed, Medline and Embase) were used to search articles published in English between January 2012 to May 2023. Grey literature was also searched using Google and Google Scholar. Only articles that addressed a framework used in cholera surveillance in Africa were included. The quality of articles was assessed using the appropriate tools. Data on the use of surveillance tools and frameworks were extracted from articles for a coherent synthesis on their deployment. Result: A total of 13 records (5 frameworks and 8 studies) were fit for use for this study. As per the time of the study, there were no surveillance frameworks specific for the evaluation of surveillance systems of cholera in Africa, however, five frameworks for communicable diseases and public health events could be adapted for cholera surveillance evaluation. None (0%) of the studies evaluated capacities on cross border surveillance, multisectoral one health approach and linkage of laboratory networks to surveillance systems. All (100%) studies assessed surveillance attributes even though there was no synergy in the attributes considered even among studies with similar objectives. There is therefore the need for stakeholders to harmoniously identify a spectrum of critical parameters and attributes to guide the assessment of cholera surveillance system performance.

An indicator framework for the monitoring and evaluation of event-based surveillance systems.

Event-based surveillance (EBS) systems have been implemented globally to support early warning surveillance across human, animal, and environmental health in diverse settings, including at the community level, within health facilities, at border points of entry, and through media monitoring of internet-based sources. EBS systems should be evaluated periodically to ensure that they meet the objectives related to the early detection of health threats and to identify areas for improvement in the quality, efficiency, and usefulness of the systems. However, to date, there has been no comprehensive framework to guide the monitoring and evaluation of EBS systems; this absence of standardisation has hindered progress in the field. The Africa Centres for Disease Control and Prevention and US Centers for Disease Control and Prevention have collaborated to develop an EBS monitoring and evaluation indicator framework, adaptable to specific country contexts, that uses measures relating to input, activity, output, outcome, and impact to map the processes and expected results of EBS systems. Through the implementation and continued refinement of these indicators, countries can ensure the early detection of health threats and improve their ability to measure and describe the impacts of EBS systems, thus filling the current evidence gap regarding their effectiveness.

Africa CDC's blueprint to enhance early warning surveillance: accelerating implementation of event-based surveillance in Africa.

Event-based surveillance (EBS) is a core component of early warning surveillance. In 2018, Africa CDC developed the first edition of an event-based surveillance framework to guide African Union Member States in implementing EBS. Country experiences during the COVID-19 pandemic demonstrated the value of data from non-traditional sources for real time situational awareness; at the same time revealed the huge gaps in strengthening this arm of surveillance. Learning from these lessons and to begin to close those gaps, Africa CDC convened subject matter experts from African Union Member States and technical partners to develop the second edition of the EBS framework, 2023 and its training materials. The revised version includes additional sections such as, the multi-sectoral one health collaboration in EBS, monitoring and evaluation, cross border EBS, and use of event management systems. The current manuscript provides an overview of the 2023 Africa CDC EBS framework and highlights experience in two countries that have successfully employed this resource in their implementation efforts.