Laboratory Analysis of Passive Samplers Used for Wastewater-Based Epidemiology Using F-RNA Bacteriophage MS2 as a Model Organism

Wastewater-based epidemiology (WBE) is an emerging public health tool that was used worldwide in response to the COVID-19 pandemic. One of the challenges with WBE is sample collection. Many countries have used passive sampling techniques for wastewater collection for SARS-CoV-2 surveillance. Due to the urgency of implementing monitoring programs, there was a lack of laboratory analysis prior to passive samplers being deployed in wastewater systems. Consequently, there are limited studies investigating viral adsorption and recovery from electronegative membrane filters used in passive samplers. This study aimed to address this gap in knowledge by conducting a laboratory-based study investigating the impact of environmental factors, including aqueous matrix, virus concentration, pH, and deployment time, on viral adsorption characteristics. The indicator organism MS2 was used as a surrogate virus for SARS-CoV-2. An increase in virus concentration led to an increase in virus adsorption/recovery. Adsorption was lowest in alkaline matrices, with an increase in viral adsorption and recovery observed as the matrix became more acidic. Interestingly, time appeared to have no statistically significant effect on viral adsorption. Based on the results from this work, more understanding of viral adsorption kinetics to passive samplers is needed before adopting this sampling methodology as a standard procedure for wastewater sampling.