O-62 Streamlining Wastewater Surveillance for Viral Tracking in Underserved Communities
Author(s):
K Farmer-Diaz, M Matthew-Bernard, S Cheetham, K Mitchell, CNL Macpherson, ME Ramos-Nino
Year of Presentation:
2025
Objective: Wastewater-based epidemiology (WBE) provides a cost-effective approach to monitoring pathogen
prevalence at a community level; however, its application
in resource-limited environments, such as the Caribbean,
remains largely underexplored. This study addressed this
challenge by developing and validating a SARS-CoV-2 protocol optimized for these settings. The primary objectives of
this study include enhancing viral recovery methods from
wastewater, comparing sample collection protocols, and
improving RT-qPCR sensitivity.
Methods: (I) Enveloped and non-enveloped surrogate viruses, Pseudomonas syringgae bacteriophage (Φ6) and coliphage MS2, respectively, were added to wastewater samples in triplicate to test the efficiency of the VIRus ADsorption ELution method with two different conditions. Samples were either untreated (NT) or pre-treated with hydrochloric acid (HCl) to a pH of 3.5. The membrane filters were eluted with Tris-EDTA-NaCl buffer followed by Trizol RNA extraction and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to quantify viral particles (II) Composite samples were collected every half hour over a 12-hour and a 24-hour period, and the viral recovery concentration listed above adjusted to a pH of 3.5 and concentrated by membrane filtration, Trizol RNA extraction followed by RT-qPCR was performed to detect viral particles (III) For each RT-qPCR mastermix, 1ul of Dimethyl sulfoxide (DMSO) or Bovine serum albumin ( BSA) was added to improve the RT-qPCR reaction.
Results: This study demonstrated that acidification of wastewater to pH 3.5 improved viral recovery, with 24-hour composite sampling demonstrating greater sensitivity compared to 12-hour composite sampling. The RT-qPCR sensitivity was further enhanced by utilizing DMSO, enabling the detection of low-concentration targets.
Conclusion: These findings highlight the potential for wastewater surveillance to inform public health strategies in low-resource settings as it provides a scalable template for implementing WBE in these settings. Future research should expand this framework to additional pathogens and approaches to enhance scalability.