Systematic evaluation of wastewater surveillance of infectious diseases in low- and middle-income countries during the COVID-19 pandemic

Wastewater-based surveillance (WBS) has emerged as an important complementary tool for infectious disease monitoring during COVID-19 pandemic, especially in high-income countries. In contrast, adoption of WBS in low- and middle-income countries (LMICs) remains constrained by resource limitations, inadequate infrastructure, and technical challenges, while methodological practices are insufficiently documented to guide future preparedness. This systematic review (January 2020–January 2025) synthesizes WHO-guided WBS methodologies applied to six priority pathogens: SARS-CoV-2, Influenza, RSV, MPXV, Salmonella, and Poliovirus across LMICs. Following PRISMA guidelines, 2,370 records were screened, and 180 studies from 37 LMICs were included. Our analysis indicates that WBS of infectious diseases has been implemented across centralized and decentralized settings using diverse sampling and analytical methods. Despite methodological variability, WBS confirmed the presence of viral signals (i.e., SARS-CoV-2) days to weeks before clinical surges, underscoring its early warning potential. Future research in LMICs should prioritize pathogen-specific protocol development, investment in WBS, and integration with national surveillance frameworks to strengthen preparedness, global health equity, and pandemic response. • This review evaluates methodological approaches used for WHO-guided WBS pathogens across LMICs. • WBS of infectious diseases has been implemented in both centralized and decentralized wastewater settings. • Studies employed diverse methodological workflows for WBS in LMICs. • Evidence from LMICs demonstrates the early warning potential of WBS for tracking infectious disease dynamics.