Using Wastewater Data in Public Health
Wastewater monitoring serves as an early detection system for outbreaks, allowing public health officials to better understand and respond to public health threats. People infected with certain viruses and bacteria, including influenza and RSV, shed the pathogens when they use the restroom or bathe, even if they are asymptomatic or do not seek medical care. Public health laboratories can test untreated samples from municipal wastewater facilities and detect the presence and burden of viruses in the population. Advances in genomic sequencing capabilities in recent years, supported by the CDC's Advanced Molecular Detection program, also allow public health laboratories to identify viruses and monitor and track emerging and circulating variants.
Isaac Benowitz, M.D., MPH is the Chief Medical Officer and State Epidemiologist at the Maine Center for Disease Control and Prevention, where he works to respond to public health threats. During an ASM-sponsored Congressional briefing in May 2024, he shared that CDC support for the state's wastewater surveillance system strengthens the state's public health preparedness and response capabilities for respiratory infections, and for some other infections like mpox. He also highlighted that, as COVID-19 reporting requirements for doctors and health care facilities are lifted, wastewater surveillance allows public health agencies to track COVID-19 activity in their communities in ways that they cannot do with any other public health tools.
"Wastewater surveillance tells us more about what's happening in our communities," Benowitz said. "We don't have to rely solely on reports from clinical encounters, which only tell us part of the story."
Applications of Wastewater Surveillance Beyond COVID-19
Crystal Hepp, Ph.D., is an associate professor at the Translational Genomics Research Institute's Pathogen and Microbiome Division and the School of Informatics, Computing and Cyber Systems at Northern Arizona University, both in Flagstaff, Ariz. Before the pandemic, Hepp and her collaborators were interested in exploring wastewater surveillance for vector-borne and other viruses, but were unable to find funding for the project. When the COVID-19 pandemic started, Hepp found herself running wastewater surveillance for SARS-CoV-2 at Northern Arizona University, the City of Flagstaff and more broadly throughout Northern Arizona.
Soon after, Hepp's lab discovered that it was relatively easy and cost effective to test samples for other viruses, including norovirus, monkeypox virus (MPXV) and influenza, prompting interest from other partners, including the City of Tempe. Working with the Tempe city government, Hepp's lab has been testing wastewater for West Nile virus and other arboviruses. They've noticed that detection of West Nile virus and dengue virus in wastewater correlates with reported human cases. The city has made these surveillance data publicly available at the city level to better inform their community of potential risks. Still, Hepp stressed the importance of using wastewater along with other surveillance strategies.
"While wastewater surveillance is a way to detect human shedding of pathogens, I don't recommend swapping out mosquito surveillance for vector-borne diseases in favor of wastewater surveillance," Hepp cautioned. "Mosquito-borne viruses start peaking in mosquito populations before spilling over to people, so mosquito surveillance gives vector control and public health agencies a chance to react before a large number of humans become infected. If your area doesn't have a mosquito surveillance program in place, wastewater surveillance can be useful to detect the occurrence of human infections, which are often asymptomatic, but ideally wastewater surveillance complements mosquito surveillance."
During the 2022 global mpox outbreak, the Oh Lab of Neurogenetics and Precision Medicine at the University of Nevada, Las Vegas, run by Edwin Oh, Ph.D., collaborated with the Southern Nevada Water Authority and the Southern Nevada Health District to set up wastewater surveillance to monitor for MPXV variants within the Las Vegas Valley. Their surveillance showed that MPXV was more prevalent in certain portions of the city. Michael Moshi, a research assistant and graduate student in Oh's lab, presented the lab's work on wastewater surveillance at ASM Microbe 2024.
"Our approach enabled near-real-time monitoring of mpox viral DNA levels," Oh explained. "This empowered public health decision-makers to strategically prioritize and deploy vaccination services, such as mobile vaccination clinics."
Oh's lab is collaborating with community partners to expand wastewater monitoring programs. These programs will track a range of biomarkers, including chemical analytes (for example, high-risk substances like fentanyl) and microbial pathogens, such as SARS-CoV-2, MPXV, influenza virus and Candida auris. The lab's wastewater surveillance work is supported by a CDC grant to the Southern Nevada Health Department to address COVID-19 health disparities.
Prior to the COVID-19 pandemic, the lab was funded by an NIH R01 grant to use genomics to study mutations associated with neurodevelopmental conditions like schizophrenia. Now, the group is applying a similar model that links wastewater pathogen genomics to human infectious diseases. By combining this approach with community engagement studies, the team aims to identify new funding opportunities for wastewater monitoring programs. By combining this approach with community engagement studies, the team aims to identify new funding opportunities for wastewater monitoring programs.
Non-clinical data from wastewater surveillance is also important-the ongoing highly pathogenic avian influenza (HPAI, H5N1) outbreak has largely affected workers on dairy farms, many of whom are immigrants and face barriers to seeking health care. In August 2024, the CDC released a dashboard showing H5 wastewater detection. While wastewater cannot determine the specific source of avian influenza (human, wildlife, agriculture or animal product), it provides an additional source of data to complement and inform public health planning and response efforts, especially when there is an absence of data when sick people do not or cannot seek care.
Looking Forward
For the 2024-2025 respiratory season, the CDC announced that the National Wastewater Surveillance System will be tracking RSV, influenza A, avian influenza A (H5) and SARS-CoV-2.
ASM is advocating for robust funding for the CDC's National Wastewater Surveillance System and its continuation during and beyond FY 2025. The President's Budget Request for FY 2025 included $20 million for the National Wastewater Surveillance System. This funding level would allow the CDC to preserve some of the wastewater capacity that the agency has built and provide the only dedicated funding for wastewater surveillance in the CDC's budget. Following this request, the Senate Appropriations Committee provided $20 million for FY 2025.
In May 2024, ASM partnered with Senator Angus King's office to hold a Congressional briefing about the importance of wastewater surveillance. ASM issued a letter of support for Representatives Robert Garcia and Don Bacon's SEWER Act (H.R. 9008) after its introduction in July 2024. ASM also supported the inclusion of Senators King, Mitt Romney and Cory Booker's PREDICT Act (S. 2237) in the Senate Health, Education, Labor and Pensions Committee's 2023 draft legislation to reauthorize the Pandemic and All-Hazards Preparedness Act.
ASM is also interested in the potential of wastewater surveillance to prevent the global spread of COVID-19, mpox, vector-borne diseases and other infectious diseases. "Establishing and strengthening wastewater surveillance in low-and-middle income countries for pathogens with pandemic potential enhances global health security," explained Wes Kim, Ph.D., Director of ASM's Global Public Health Programs. "The U.S. Government and other investors should increase support for wastewater surveillance systems in low-resource settings."
The U.S. House of Representatives Committee on Appropriations proposed significant cuts for research and public health programs at the CDC, including the National Wastewater Surveillance System and the Advanced Molecular Detection Program. Tell your members of Congress to oppose these drastic cuts.
