Safeguarding Public Health through the Wastewater Program(s)
Environmental monitoring is a cornerstone of modern public health. From detecting emerging pathogens to tracking community-level disease trends, wastewater disease surveillance has become an essential part of the public health toolbox. To ensure laboratories generate accurate and reliable results, laboratory proficiency testing programs play a critical role.
Why Wastewater Surveillance Matters
Wastewater surveillance provides an efficient, non-invasive and relatively unbiased way to monitor pathogens circulating in a population, often demonstrating a spike in cases days or even weeks earlier than traditional case reporting. Launched in September of 2020, the Wisconsin Wastewater Monitoring Program (WWMP) has been reporting to the Wisconsin DHS and the Centers for Disease Control and Prevention (CDC) wastewater levels of SARS-CoV-2. This reporting has since been expended to include influenza (A, B, H5N1), respiratory syncytial virus, norovirus, mpox virus and most recently measles. These data help to fill in some of the existing clinical surveillance gaps, aiding public health agencies in anticipating outbreaks, making timely and effective policy decisions, allocating resources, and conducting appropriate public messaging campaigns.
In just a few years, through the CDC’s National Wastewater Surveillance System (NWSS), the United States has established a robust network of laboratories reporting pathogen concentrations in wastewater. Though impressive, this rapid expansion of the network has outpaced the development of standardized laboratory and data analysis protocols, resulting in substantial data variability, and making cross-network comparability more difficult. In July 2023, the CDC named the Wisconsin Wastewater Monitoring Program a National Center of Excellence for wastewater surveillance in recognition of its achievements and leadership within the NWSS network.
Wisconsin’s Wastewater Surveillance Laboratory PT
Recognizing the urgent need for cross-network data standardization, WWMP has established and implemented a Wastewater Surveillance Laboratory Proficiency Testing (PT) Program with the following goals:
- Identify key methodological factors that contribute to inter-laboratory variability
- Help identify calculation and reporting data errors
- Identify low and high-performing protocols
- Identify under-performing laboratories and assist with troubleshooting and method optimization
The Wastewater PT Program has conducted three rounds of testing to date, focusing primarily on respiratory pathogens. Participating laboratories received blinded wastewater samples and were instructed to perform their routine wastewater pathogen protocols, and to submit a metadata report describing all the pertinent details of their process. These metadata were then used for quality assurance and to gain insights into the methodological factors that may influence performance. In return, participants were issued comprehensive summary reports, laboratory support, and assessment of qualitative outcomes via follow-up surveys. The survey outcomes to date suggest that the participating laboratories have found the exercises valuable, and a large proportion of newly participating labs were able to correct a reporting mistake. “I’m looking forward to continued guidance on method optimization” wrote one recent participant.
The Wisconsin Wastewater Monitoring Team at WSLH is currently conducting PT exercises at a twice-yearly cadence. WWMP is proud to help advance nationwide laboratory competency in wastewater monitoring—protecting communities today and preparing for tomorrow’s challenges. For more information about this program or to enroll in the future PT exercises, you can contact WSLH at WastewaterTesting@slh.wisc.edu.
