A systematic review of the effects of climate change on childhood diarrhoeal disease burden in low and middle income countries

Abstract Background and objective Climate change significantly impacts human health, particularly worsening diarrhoeal disease burden in low- and middle-income countries (LMICs). While children under five experience the highest disease burden, climate-health relationships affect all age groups. This systematic review examined how climate change variables (temperature, precipitation, extreme weather events) impact diarrhoeal disease burden in LMICs. Methods We conducted a comprehensive literature search from January 2010 to December 2024, using Medical Subject Headings (MeSH) terms and keywords related to climate change, diarrhoeal diseases, and geographical locations in middle- and low-income countries. We descriptively synthesized the extracted data. Key findings The systematic search identified 39 studies meeting inclusion criteria, of which 34 studies (87.2%) reported statistically significant positive associations between climate variables and diarrhoeal disease outcomes. Temperature effects were examined in 28 studies (71.8%), with 25 studies (89.3%) finding significant positive associations and consistent effect sizes of 3–5% increased diarrhoea risk per 1 °C temperature rise across diverse settings. Rainfall showed bidirectional patterns: 14 studies (63.6%) found increased disease with heavy rainfall in monsoon regions, while 8 studies (36.4%) found increased disease during rainfall shortage in semi-arid settings. Regional vulnerabilities included Nepal showing 4.4% increased diarrhoea per 1 °C in mountain regions, and South/Southeast Asia experiencing 39% increased probability at 30–40 °C. Infrastructure analysis (12 studies) revealed household water improvements reduced climate-associated risk by 15–35%, while community-level interventions showed 40–85% protection. Conclusions The review demonstrates clear evidence of climate-disease relationships mediated by environmental, social, and infrastructural factors. Consistent temperature-disease relationships exist across regions, with quantifiable disease burden increases corresponding to rising temperatures and rainfall patterns. The findings highlight the importance of limiting global warming below 2 °C, preferably 1.5 °C above pre-industrial levels, as outlined in the Paris Climate Agreement, to minimize future diarrhoeal disease burden.