Wastewater surveillance was a valuable component of the U.S. public health response in the nation’s emergency response to the COVID-19 pandemic, and is worthy of further development and continued investment, says a new report from the National Academies of Sciences, Engineering, and Medicine. The report offers recommendations to strengthen nationwide coordination and ensure a national wastewater surveillance system that is flexible, equitable, and sustainable to inform the public health response to COVID-19 and future infectious diseases.
Wastewater-based infectious disease surveillance systems detect the presence of biomarkers of infection, such as DNA or RNA, that are shed into a municipal sewer system. These surveillance systems can be used to identify changing levels of a pathogen or identify newly emergent variants in a community. The National Wastewater Surveillance System (NWSS) was launched by the Centers for Disease Control and Prevention in 2020 in response to the COVID-19 pandemic. Wastewater surveillance data proved to be useful during the pandemic to inform public health action, such as the allocation of public health and clinical resources, and will remain a critical data source in responding to the virus, says the report. As at-home COVID-19 testing rose, individual reporting of cases decreased, emphasizing the importance of other tools such as wastewater surveillance for monitoring new variants and their spread.
“Looking forward, the success of a national wastewater surveillance program for infectious diseases relies on building public trust in the system, especially when ‘surveillance’ can be such a charged term in some communities,” said Guy Palmer, Regents Professor of Pathology and Infectious Diseases at Washington State University, and chair of the committee that wrote the report. “Investment in this national system is important for strengthening public health, but sustaining that investment requires clearly communicating how wastewater surveillance benefits our communities while addressing privacy concerns.” The report also offers recommendations for developing a more representative and equitable national system of community-level wastewater surveillance.
Vision for a National Wastewater Surveillance System
The report presents a vision for a national wastewater surveillance system that would be able to track multiple pathogens simultaneously and pivot quickly to detect emerging pathogens. The system must also be fiscally and operationally sustainable and monitor populations equitably. When evaluating potential targets for future wastewater surveillance, the report says, CDC should establish a transparent process for prioritizing pathogens, and consider three criteria: the public health significance of the threat, the analytical feasibility for wastewater surveillance, and the usefulness of community-level data to inform public health action.
In addition to expanding wastewater surveillance to currently underserved geographic areas, the NWSS sampling program, including the number and distribution of sampling sites and the frequency of sampling, should be subject to intentional design based on analysis of data for prioritized pathogens. Specific “sentinel” sites should be incorporated, such as large international airports or zoos, to monitor for specific emerging pathogens at their points of entry.
Predictable and sustained federal investment
The COVID-19 pandemic emergency spurred researchers and utilities to volunteer in support of the effort, but a sustained national wastewater surveillance system necessitates a shift from volunteerism to a strategic national plan supported by federal investments. Predictable funding is essential to maintain the workforce capacity and to continue to advance sampling and analysis methods and tools, the report says.
Public communication, ethics, and partnership
The report states that although the benefits of responsibly managed wastewater surveillance outweigh the associated ethical concerns, CDC should develop and disseminate additional materials designed to inform the public about the data generated in wastewater surveillance and how these data are used. In addition, CDC should establish a standing ethics advisory committee to propose guidelines about how data may be shared and to evaluate future expansions of data collection and access, with a strong firewall to preclude use of data by law enforcement.
Close coordination among public health agencies, analytical laboratories, and wastewater utilities is essential to generating reliable data and supporting appropriate interpretation and use of data, the report says. The committee recommended CDC as the best organization to continue leading federal coordination among partners.
The report commends CDC for launching two initial Centers of Excellence for wastewater surveillance, which will help support targeted research and training. CDC should further engage the scientific community and ensure that a trained workforce can meet current and future needs of the broad national system. The second phase of the National Academies study will offer a detailed assessment of technical constraints and opportunities for the NWSS.
The study — undertaken by the Committee on Community Wastewater-Based Infectious Disease Surveillance — was sponsored by the U.S. Department of Health and Human Services.