Dengue in Sub-Saharan Africa: integrated surveillance, disease burden, diagnostic and care

"Dengue, transmitted by Aedes mosquitoes, poses a significant global health challenge, with an unprecedented number of more than 6.5 million cases of dengue fever and more than 7,300 dengue-related deaths reported in 2023. Sub-Saharan Africa (SSA) faces numerous upheavals, including climate change and urbanization, which foster dengue emergence. Of 200, 000 suspected dengue cases (45% confirmed, 900 deaths, case fatality rate [CFR] ≈0.5%) reported from more than 30 countries of the WHO Afro region between 2013 and 2023, more than 170, 000 (750 deaths) were recorded in 2023. Despite increasing dengue virus (DENV) circulation in SSA, data regarding dengue in the region remains fragmentary, limiting understanding of the disease's true burden. Key gaps include insufficient diagnostic capacities, frequent asymptomatic infections, limited disease awareness, inadequate entomological investigations, and lack of robust surveillance systems. DENGAFRICA aims to address some of these gaps and improve our understanding of dengue fever as a global health threat in SSA, through an integrated, interdisciplinary, and multinational research approach. It seeks to decipher the burden of human disease, factors influencing DENV transmission by local vectors, and the diversity of DENV strains through genomics. DENGAFRICA addresses several research questions related to human disease, vectors, and viral genomics. For human disease, it aims to determine dengue prevalence in patients with acute undifferentiated febrile illness (AUFI), evaluate diagnostic performances of point-of-care tests and WHO case definitions, assess the risk of severe dengue in individuals with comorbid conditions, with a focus on sickle cell disease (SCD), and explore perceptions, beliefs and behaviours about dengue, vector protection and dengue vaccines. For vectors, it investigates the utility of immature stage surveillance, temporal dynamics of vectors, performance of monitoring technologies, vector competence, and the impact of landscape and climate on vector distribution and resistance. For viral genomics, it seeks to identify circulating serotypes and genotypes, their introduction and replacement dynamics, and potential associations with clinical phenotypes. DENGAFRICA is organized into six work packages (WPs): Project coordination, governance and data: Ensures project execution, data collection, and integration. Clinical Epidemiology: Focuses on dengue screening in outpatients, establishing cohorts of dengue cases, and studying hospitalised cases. Entomology: Reviews vector transmission data, conducts systematic monitoring of Aedes mosquitoes, and assesses vector competence. Virology and viral genomics: Provides DENV detection solutions, conducts external quality assessments, isolates DENV strains, and performs genomic and phylogenetic studies. Human and Social Sciences: Studies dengue perceptions and beliefs, protective behaviours, and vaccination acceptability. Training, engagement, communication and dissemination: Trains healthcare workers, builds capacity through technology transfer, engages communities, and disseminates results. Expected Outcomes: DENGAFRICA aims to produce key indicators on dengue in SSA, improve disease detection and surveillance, enhance awareness and clinical management, and provide evidence for innovative vector monitoring and risk prediction approaches. The project will contribute to technological innovation, capacity building, and the structuration of a research network in arboviral sciences in SSA."