An Evaluation of the Presence and Persistence of Viruses in Varying Water Matrices

A majority of sewage worldwide enters the environment untreated, creating a global health problem. Understanding and characterizing the presence and persistence of enteric viruses is critical to preserve public health, inform mitigation techniques, and feed risk assessment analyses. The main motivation of the work described in this dissertation is to characterize the inactivation kinetics under different conditions, specifically for human norovirus and Lassa virus. This dissertation investigates the presence and persistence of pathogenic viruses in water to inform best practices for water quality management. The four main objectives addressed in this dissertation were to (1) determine the persistence of viable human norovirus and associated RNA in different water sources, (2) understand the heat inactivation kinetics of human norovirus compared to surrogate MS2 bacteriophage, (3) evaluate the stability of infectious Lassa virus in wastewater and surfaces and chlorine inactivation, and (4) characterize the concentration efficacy of novel Nanotrap Microbiome Particles. Ultimately, the results from this research will improve risk assessments to protect public health and better wastewater-based epidemiology methods to track viral pathogens of interest. The research presented in this dissertation addresses critical gaps in viral persistence, inactivation, and detection in various water environments and treatment scenarios, offering significant implications for public health. The work with viable human norovirus provides the first robust assessment of the persistence in different water matrices, filling a historical gap that was due to a lack of cell culture systems. This study, along with the results from the heat inactivation study, emphasizes the limitations of molecular methods in representing viable virus decay, and therefore, the associated infectious risk, which will guide future efforts in developing more accurate risk assessment models. Furthermore, the environmental persistence of Lassa virus results are the first of their kind, which will inform future strategies to mitigate environmental transmission in real-world scenarios. The heat inactivation work for viable human norovirus and MS2 bacteriophage and the chemical disinfectant treatment with Lassa virus highlight effective treatment strategies for both viruses. These results can inform treatment protocols for heat inactivation and disinfection to safeguard public health. Using Nanotrap Microbiome Particles in wastewater as a viral concentration method underscores the potential of advanced concentration technologies in future wastewater surveillance workflows. The results provides a pathway for optimizing surveillance pipelines, ultimately improving our ability to monitor and respond to viral pathogen spread throughout our communities. Together, the findings of this dissertation offers a comprehensive framework to improve environmental monitoring, public health interventions, and viral risk assessments and management strategies.