# P-1146. Wastewater-Based Epidemiology for Emerging Pathogens in a Northern California Community Hospital, November 2024 to April 2025

## TL;DR

This study used wastewater testing to detect emerging pathogens in a Northern California hospital, finding viruses like Influenza A and Measles even without clinical cases.

## Contribution

The study explores wastewater-based epidemiology in a hospital setting to detect emerging pathogens with high sensitivity.

## Key findings

- Influenza A was consistently detected in wastewater samples.
- Measles and Influenza A subtype H5 genetic material was found despite no clinical cases.
- Candida auris was detected in one sample, suggesting a possible undetected case.

## Abstract

Emerging infections can lead to hospital outbreaks, and have the potential to cross borders and impact global health. While wastewater-based epidemiology (WBE) has been effectively utilized to monitor respiratory viral circulation at the community level, its application in hospital settings remains largely unexplored. We used WBE to gain insights into emerging pathogen circulation within a hospital environment.Emerging Pathogens detected in Wastewater from Tri-valley Hospital

Emerging Pathogens detected in Wastewater from Tri-valley Hospital

We collected 500 ml weekly composite wastewater samples using a Teledyne ISCO 5800™ autosampler from Tri-Valley Hospital, which is a 200-bed community hospital in Northern California. Samples were processed within 48 hours, with solids separated through centrifugation. Nucleic acids were extracted using column-based kit Zymo R2002. Droplet digital PCR was performed to detect viral nucleic acid using assays for viral genes detection developed and tested by the WastewaterSCAN program. We tested the hospital wastewater samples for presence of SARS-CoV-2, Respiratory syncytial virus (RSV), Measles, Influenza A, Influenza A subtype H5, and Candida auris. Data was analyzed using the QX Manager Software Version 2.2 (BioRad, #168032).

Influenza A virus was consistently detected during the observation period, while SARS-CoV-2 and RSV had more variability and less concentration (Figure). Interestingly, the presence of measles virus and Influenza A subtype H5 genetic material was detected in at least three samples. Candida auris was absent in most samples tested, except one week. No human cases of Measles, Influenza A subtype H5 or Candida auris were detected in Tri-valley Hospital during the observation period.

WBE was reflective of classical epidemiology for SARS-CoV-2, RSV and Influenza A. The detection of Measles and Influenza A subtype H5 despite lack of clinical cases may signify this strategy has a high sensitivity and may yield viral shedding post vaccination (measles) or consumption of dairy products (Influenza A subtype H5). The detection of Candida auris in wastewater may represent an undetected case in the hospital.

All Authors: No reported disclosures