Technical framework for wastewater-based epidemiology of SARS-CoV-2

Area of Science:

• Environmental science
• Public health
• Molecular biology

Background:

• Wastewater-based epidemiology (WBE) is emerging as a crucial tool for community-level disease surveillance.
• Standardized protocols for SARS-CoV-2 monitoring in wastewater are currently lacking.
• Accurate quantification is essential for reliable public health insights.

Purpose of the Study:

• To establish a comprehensive technical and theoretical framework for SARS-CoV-2 quantification in wastewater.
• To develop a method for estimating community infection ratios using wastewater data.
• To enable horizontal and vertical comparability of WBE data through a standardized approach.

Main Methods:

• Development of a relative quantification framework using quantitative polymerase chain reaction (qPCR).
• Incorporation of a human-specific biomarker as an internal reference for normalization.
• Analysis of critical factors influencing virus detectability and infection ratio estimation, including concentration methods, lag periods, shedding amounts, sewage generation rates, decay kinetics, and hydraulic retention time (HRT).

Main Results:

• Theoretical simulations identified per capita virus shedding amount and sewage generation rate as primary factors affecting virus detectability.
• SARS-CoV-2 RNA decay in wastewater was found to be a slow process with potentially limited impact on detection.
• The proposed framework demonstrates the potential to detect a single infected individual within a population of 400,000 under optimal conditions.

Conclusions:

• The developed framework provides a standardized approach for WBE of SARS-CoV-2.
• Accurate estimation of infection ratios is achievable through careful consideration of influencing factors.
• This methodology enhances the utility of WBE as a public health surveillance tool.