Developing wastewater-based surveillance schemes for multiple pathogens: The WastPan project in Finland

Area of Science:

• Environmental microbiology
• Public health surveillance
• Infectious disease epidemiology

Background:

• Wastewater contains pathogens, offering potential for disease surveillance.
• Antimicrobial resistance (AMR) is a growing global health concern.
• Effective wastewater-based surveillance (WBS) requires robust methodologies for multiple pathogens.

Purpose of the Study:

• To establish wastewater-based pandemic preparedness for diverse pathogens and AMR in Finland.
• To outline the experiences and methodologies of the Finnish WastPan project.
• To assess the feasibility and effectiveness of WBS for public health monitoring.

Main Methods:

• Wastewater samples collected from 10 treatment plants covering 40% of Finland's population (2021-2023).
• Validation of WWTP selection against national data for specific bacterial pathogens.
• Dual workflow: culture-based analysis (bacteria, fungi) and molecular analysis (viruses, bacteria, AMR genes, parasites).
• Inter-laboratory comparison of SARS-CoV-2 monitoring using N1 and N2 assays to assess reproducibility.

Main Results:

• WastPan successfully piloted WBS for multiple pathogens, including Extended Spectrum Beta-lactamase-producing bacteria.
• Similar SARS-CoV-2 positivity trends were observed between laboratories, but the N2 assay showed higher detection rates.
• The choice of monitoring assays significantly impacts WBS sensitivity.
• Pathogen-specific characteristics should guide sampling frequency and population coverage.

Conclusions:

• Wastewater-based surveillance is a valuable tool for assessing community health and pandemic preparedness.
• The infrastructure developed for COVID-19 WBS can be leveraged for broader pathogen monitoring.
• Optimized target prioritization, legislative support, and sustained funding are crucial for future WBS implementation.