Surveillance of SARS-CoV-2 RNA in wastewater: Methods optimization and quality control are crucial for generating reliable public health information

Monitoring for SARS-CoV-2 RNA in wastewater through the process of wastewater-based epidemiology provides an additional surveillance tool, contributing to community-level screening and prevention efforts as these measurements have preceded disease cases in some instances. Numerous detections of SARS-CoV-2 RNA have been reported globally using various methods, demonstrating the technical feasibility of routine monitoring. However, to reliably interpret data produced from these efforts for informing public health interventions, additional quality control information and standardization in sampling design, sample processing, and data interpretation and reporting are needed. This review summarizes published studies of SARS-CoV-2 RNA detection in wastewater as well as available information regarding sample concentration, extraction, and detection methods. The review highlights areas for potential standardization including considerations related to sampling time and frequency relative to peak fecal loading times; inclusion of appropriate information on sample collection points; sample volume collected; transport and storage conditions; sample concentration procedures; RNA extraction process and performance; effective sample volumes; recovery efficiency testing; PCR inhibition; process controls throughout sample collection and processing; and PCR standard curve performance. Researchers are advised to follow the Minimum Information for Publication of Quantitative Real-Time PCR guidelines. Adhering to these recommendations will enable robust interpretation of wastewater monitoring results and improved inferences regarding the relationship between monitoring results and disease cases.