Implementation of wastewater-based epidemiology in a Northern California acute care hospital: a pilot study, June-July 2024.

AIM: The aim of this study was to evaluate the feasibility and performance of wastewater-based healthcare epidemiology for monitoring respiratory viruses and antimicrobial resistance genes.

METHODS

We conducted a pilot study at an 800-bed academic quaternary care hospital in Northern California. Composite wastewater samples were collected weekly over three timepoints (June-July 2024) from the main hospital outflow. Droplet digital polymerase chain reaction was performed to quantify nucleic acids from respiratory viruses (SARS-CoV-2, influenza A, and respiratory syncytial virus) and antimicrobial resistant genes (ARGs; mecA, vanA, KPC, NDM, OXA-48, and VIM). Viral levels were compared with hospital testing data and community wastewater trends. Antimicrobial resistance genes were compared with contemporaneous clinical cultures.

FINDINGS: Sampling was logistically feasible but constrained by equipment size and placement limitations. Viral nucleic acid levels in hospital wastewater broadly reflected hospital testing results and community wastewater trends. By contrast, ARG levels showed limited alignment with clinical culture data. mecA levels were low despite an elevated number of methicillin-resistant Staphylococcus aureus cultures, while vanA and carbapenemase genes were abundant, including during weeks with no corresponding clinical cases.

CONCLUSIONS

Wastewater-based healthcare epidemiology captured trends in hospital respiratory virus testing but showed limited concordance with culture-based detection of resistant bacteria. While not suited for case detection of resistant pathogens, it may serve as a system-level tool to assess the hospital resistome, antimicrobial pressures, and potential environmental transmission risks.