Wastewater surveillance for SARS-CoV-2: Lessons learnt from recent studies to define future applications.

Area of Science:

• Environmental Science
• Public Health
• Molecular Biology

Background:

• Wastewater-based epidemiology (WBE) is crucial for monitoring infectious diseases like SARS-CoV-2, especially when clinical testing is limited.
• WBE provides insights into virus transmission dynamics, lockdown impacts, and asymptomatic infections.
• The review highlights the essential role of WBE in public health surveillance.

Purpose of the Study:

• To review methods and results of SARS-CoV-2 quantification in wastewater.
• To develop a WBE framework for SARS-CoV-2 incorporating lessons learned.
• To identify challenges and propose recommendations for future WBE applications.

Main Methods:

• Comprehensive literature review of recent studies on SARS-CoV-2 quantification in wastewater.
• Analysis of various sample concentration and virus quantification techniques.
• Comparison of different primer sets used in quantitative polymerase chain reaction (qPCR).
• Correlation analysis between gene copy numbers and reported infection data, including lag periods.

Main Results:

• Multiple primer sets exist for qPCR, but no consensus on the most sensitive one.
• qPCR results, especially with a lag period for asymptomatic cases, show potential for estimating new infections.
• Key challenges in SARS-CoV-2 detection include sample processing, RNA decay, and disinfection effectiveness.

Conclusions:

• WBE is a valuable tool for SARS-CoV-2 surveillance, but standardization is needed.
• Future research should focus on occupational safety, greywater disinfection, viral RNA decay, digital PCR, and large-scale international studies.