Wastewater Surveillance System Looks to Offer Early COVID Detection

By Matt Phillion

The threat of antimicrobial resistance—the ability of germs to defeat the drugs designed to kill them—continues to be a constant global health concern. Infections caused by antimicrobial-resistant germs kill more than 35,000 people in the U.S. every year. To combat this, the CDC invests in the public health response to antimicrobial resistance, transforming how the U.S. and the world at large work to slow its spread.

In fiscal year 2022, the CDC invested more than $120 million in annual funding and over $900 million in temporary supplemental funding to help health departments and other healthcare partners fight and prevent the wide range of infections related to antimicrobial resistance—both known and emerging threats alike.

One federally funded program is the National Wastewater Surveillance System (NWSS). Launched in September 2021, the program works to coordinate and improve the nation’s capacity to track the presence of SARS-CoV-2 (the virus causing COVID-19) in wastewater samples across the country. People infected with the virus can shed it through their waste even if they aren’t exhibiting symptoms, enabling the surveillance system to capture SARS-CoV-2’s presence in a community and allowing the community to take steps to prevent its spread.

“Wastewater surveillance has been used since the 1940s,” says Angela Coulliette-Salmond, PhD, lieutenant commander in the U.S. Public Health Service and program lead for the Healthcare-Wastewater Antimicrobial Resistance Network (H-WARN) in the CDC’s Clinical and Environmental Microbiology Branch, Division of Healthcare Quality Promotion. Historically, this type of surveillance has been used to identify poliovirus and continues today in global efforts to eradicate poliomyelitis, as well as to follow trends of opioid use.

“Due to the COVID-19 pandemic, the CDC launched the National Wastewater Surveillance System to build up the nation’s capacity to track trends for the presence of the virus, which gave us a great opportunity to apply it for healthcare facilities as well,” says Coulliette-Salmond.

H-WARN, as part of the overarching investment the CDC is making in antimicrobial resistance prevention, doesn’t just bolster existing detection systems—it kicks them up to the next level. “Part of that investment is doing innovative, novel solutions that help keep people safe from the threat of outbreaks. It’s all connected to this broader goal,” she says. “We’re focusing on wastewater surveillance to detect and track antimicrobial resistance at long-term acute care hospitals, as well as skilled nursing homes.”

Data from wastewater testing complements existing surveillance systems to provide an efficient community sample. It also provides more information about communities where timely COVID-19 clinical testing is underused or unavailable, as well as data for different communities within a county. Healthcare facilities are natural partners in this process, with at-risk patients and residents who will benefit from early detection and intervention.

In the first few years, the program has focused on data collection and the feasibility of sampling at these facilities. “CDC is building a foundation for a long-term solution to help take the burden off healthcare personnel for screening residents, but this will also complement what they’re already doing in their facilities,” says Coulliette-Salmond. “Once we better understand the circulation of antimicrobial resistance in a facility, we will be able to determine the best frequency of screening for residents.”

Getting everyone on the same page

Using this sort of surveillance is a big lift, incorporating knowledge from a range of fields: the sampling at the manhole, the engineering involved, the microbiology and lab science needed to detect the resistant genes and organisms, and the epidemiological and clinical information, not to mention the healthcare facility buy-in factor. But the silver lining to the effort is increased openness and communication, says Coulliette-Salmond.

“We’re all collaborating with each other more,” she says. “We want to do it right from the beginning. Having everyone on the same page and collaborating together really is key to this type of surveillance being successful.”

While the addition of nursing homes and other healthcare facilities is a recent development, the NWSS has already worked with other organizations, such as prisons and universities, as well as in general communities. “We want to have interventions early on to help prevent further spread of antimicrobial resistance and other public health threats,” says Judith Noble-Wang, deputy chief for the CDC’s Division of Healthcare Quality Promotion, Clinical and Environmental Microbiology Branch.

If there are any emerging resistance genes, this program wants to detect them early. “This is essential to protect patients,” says Noble-Wang. “Early detection allows you to prevent spread by implementing infection control measures in the healthcare facility.”

Longer-term goals include developing the capacity for a national network that allows different jurisdictions to conduct early detection, as well as establishing data systems that can talk to each other and analyze results in real time. “We want to have real-time data and real-time understanding of what’s going on in facilities so we can offer earlier recommendations and guidance,” says Coulliette-Salmond.

Lessons learned

The successes with wastewater surveillance for poliovirus, opioid use, and SARS-CoV-2 has the team optimistic that, in working with facilities for early detection, they can have a huge impact on patient care.

“We understand from the start what questions to ask and have a starting point for methods that work well out in the field—and we have a lot of background information and data collection to move forward with this program,” says Coulliette-Salmond. “The big dream would be to have a rapid method out in the field at nursing homes, for example, for early detection: take a sample, know what’s going on at the facility, tell the facility what we’ve found, and have an immediate impact.”

Antibiotic use is amplified in healthcare settings; particularly in long-term care, antibiotics can contribute to resistant genes mutating and circulating. “It’s always been a concern, especially in our division, to protect patients,” says Coulliette-Salmond. “How can we detect [resistance] earlier without having to screen residents on a regular basis, which is not an enjoyable process for the residents?”

The ability to test wastewater for early antimicrobial resistance detection can remove some of that invasiveness and frustration from the residents and the staff who care for them. “There’s been a lot of information shared already with the public about wastewater surveillance,” says Noble-Wang. “That’s helpful in communicating our goals here. I think that’s certainly benefitted the implementation of this kind of research.”

There is much knowledge to be gained, and the ultimate impact on community health will depend on how that information is used. “We’ll need a lot of buy-in and teamwork from the stakeholders, but we have the engagement of these facilities right now,” says Noble-Wang. “They are very engaged in combatting antimicrobial resistance. This will help us in the long term building this network to provide early signals and benefit everyone.”

The nursing home component in particular is a special opportunity because nursing homes connect to other types of facilities. Residents can be moved from a hospital to a rehabilitation facility to a skilled nursing home; meanwhile, healthcare personnel can also have multiple jobs at these facilities. Healthcare facilities are a connected network across which antimicrobial resistance can take hold.

“This is a great way to communicate how beneficial wastewater surveillance for antimicrobial resistance could be for those settings,” says Noble-Wang.

“Patients move from one facility to another,” says Coulliette-Salmond. “And because we know these genes move around, we want to be able to curtail and prevent the spread to other facility types as well.”

Matt Phillion is a freelance writer covering healthcare, cybersecurity, and more. He can be reached at matthew.phillion@gmail.com