Communicable Disease Surveillance in South Africa and LMICs: A Systematic Review of Systems, Challenges, and Integration with Environmental Health.

Communicable disease surveillance systems are crucial for global health security, particularly in low- and middle-income countries (LMICs) where infectious disease burdens remain high. Despite disease surveillance systems being in place, the evidence on their implementation, challenges, and integration with environmental health remains fragmented. This systematic review assesses the design, implementation, and challenges of these systems across LMICs, with a focus on South Africa and the broader Sub-Saharan African region. Using PRISMA guidelines and the PICOS framework, searches across four databases identified 325 articles published between 2010 and 2025, of which 56 (17%) were included for analysis. Thematic synthesis revealed key trends, disease priorities, and surveillance tools. South Africa contributed the highest number of articles (25%), while Sub-Saharan Africa accounted for 54% overall. COVID-19 was the most frequently studied disease (20%), followed by cholera, typhoid, and measles. The Integrated Disease Surveillance and Response (IDSR) framework appeared in 25% of articles, while District Health Information Systems 2 (DHIS2) was referenced in 11%, reflecting modest adoption of digital platforms. Reported challenges included underreporting, inconsistent case definitions, limited digital infrastructure, and weak feedback mechanisms. Although integration of environmental health was widely recommended, it was marginally implemented. Overall, LMICs surveillance systems remain constrained by operational and structural limitations, underscoring the need for digital investment, environmental indicators integration, and community-based approaches to strengthen epidemic preparedness.