Wastewater-based surveillance for mpox: Methodological advances and surveillance performance—A systematic review

Despite the growing use of wastewater-based surveillance (WBS) for monitoring mpox outbreaks worldwide, a comprehensive understanding of the complete methodological workflow—from sampling and laboratory analysis to data interpretation—remains limited. This systematic review aimed to evaluate (i) the geographical distribution of mpox WBS studies, (ii) concordance with clinical surveillance and the potential of early-warning detection, (iii) methodological approaches, and (iv) the influence of sample type on detection sensitivity. Following PRISMA 2020 guidelines, original studies on WBS of monkeypox virus (MPXV) were identified through systematic searches of Google Scholar, PubMed, and Scopus up to January 2026. Studies that did not report original WBS data were excluded. Where applicable, methodological quality and risk of bias were assessed using predefined criteria. Due to substantial methodological heterogeneity among the included studies, findings were qualitatively synthesized using a thematic approach based on the review objectives. Thirty-five studies met the inclusion criteria. Most were conducted in the United States, Canada, China and Switzerland, highlighting limited global coverage and a notable lack of studies from low- and middle-income countries (LMICs), particularly sub-Saharan Africa. Multiple studies detected MPXV in wastewater before or despite few, clinically confirmed cases, demonstrating the value of WBS for early outbreak detection and identifying otherwise undiagnosed community transmission. MPXV concentrations were consistently higher in wastewater solids than in liquid influent, with centrifuge pellets and primary sludge providing greater analytical sensitivity than supernatant samples. However, substantial variation in sampling strategies, concentration methods, nucleic acid extraction protocols, and molecular assays limited direct comparison across studies. Overall, current evidence supports WBS as a sensitive complementary tool for mpox surveillance. Harmonized methodologies, wider implementation in LMICs, and integration with conventional public health surveillance are needed to strengthen global outbreak preparedness and One Health surveillance.