A systematic review investigating emerging trends between Extreme Weather Events (EWEs) and infectious disease outbreaks in South Africa

Introduction: Extreme weather events (EWEs) are increasing in frequency and intensity due to climate change, exacerbating health risks, particularly for vulnerable populations. Infectious diseases are climate-sensitive, yet microbial dynamics during and after EWEs remain poorly understood. This systematic review examines if there are emerging trends and associations in infectious disease outbreaks and health care following EWEs in South Africa.

Methods: A comprehensive search across fifteen electronic databases was conducted using Cochrane systematic review principles, including double screening and double extraction. Studies describing outbreaks of infectious diseases related to EWEs in South Africa were included, considering all study designs. A PRISMA diagram details the screening process, and quality appraisal was conducted using JBI checklist tools or a mixed-methods assessment tool.

Results: The review did not identify any primary studies that explicitly examined the presence of specific pathogens contaminating the environment in relation to EWEs in South Africa. Instead, the available literature predominantly focused on clinical symptom patterns or broader syndromic descriptions, with limited attention to pathogen-specific detection or characterisation. This highlights a significant evidence gap in microbial-level assessments of how EWEs influence environmental contamination. However, findings indicate the presence of infectious diseases post-EWEs, with three key themes emerging: (1) climate variables, (2) population vulnerabilities, and (3) policy effects. The review highlights the need for longitudinal microbiological data to improve outbreak prediction and preparedness.

Discussion: This review underscores a significant research gap and calls for an integrated approach combining environmental monitoring with pathogen diagnostics. Large-scale longitudinal studies and enhanced collaboration public health, environmental surveillance, laboratory capacity, and disaster preparedness are needed. Early Warning Systems should incorporate climate variables to predict disease outbreaks, addressing the limited diagnostics, lack of environmental microbiology, fragmented surveillance data effectively.