One of Patrick Green’s first tasks every day is to turn on the faucet and fill the bottle with sludge.

Modesto, a city of nearly 250,000 people in California’s San Joaquin Valley, is a utility plant operator, and Green helps keep the city’s sewers open and treats wastewater to acceptable levels of safety. But in recent months, he and his colleagues have added COVID-19 detection to their job descriptions.

Larger items, from baby wipes that shouldn’t be flushed to car parts, are filtered out at the treatment plant at Modesto’s sewer confluence. The rest is directed into a huge bucket, where the solids settle at the bottom. When researchers looked for SARS-CoV-2, the virus that causes COVID, they took samples from 3 feet of black sludge.

Across the country, academics, private companies, public health authorities and wastewater treatment plant operators have been working to develop a new public health tool that could have uses well beyond COVID. Wastewater monitoring is not a new concept, but the scale and scope of the current pandemic has pushed the technology beyond the narrow walls of academic research into wider public use as a key tool for tracking COVID surges and variability at the community level.

Sewage monitoring has proven so useful that many researchers and public health officials say it should become standard practice for tracking infectious diseases, as in many other countriesBut whether that happens — and which communities have access to it — depends on the country’s ability to significantly scale up the approach and make it viable in both rich and poor communities.

Like many other public health tools, wastewater testing initially took off in big cities and college towns, where research expertise, equipment and funding were available. The Modesto project provides a glimpse into the challenges and opportunities of using this technology in resource-constrained communities.

“You should be injecting more resources into underserved places because of their high disease burden,” said Colleen Naughton, a professor of engineering at the University of California, Merced. Valley Farm Town.

Modesto Utilities Director William Wong oversees the water supply and sewerage operations. From the early days of the pandemic, he wanted to monitor SARS-CoV-2 in urban sewage. This is a natural extension of his work; the safe disposal of feces is fundamental to public health and modern society. “We’ve always thought that what we’re doing is protecting public health,” Wong said.

For COVID surveillance, wastewater is not subject to the tricky inconsistencies that come with human coronavirus testing. Shortages of COVID testing have been an ongoing problem throughout the pandemic, stemming both from supply chain shortages and wide disparities in local government responses. Long delays in test results could leave health officials weeks behind in testing and monitoring infection trends.

Recently, there has been an increasing number of home tests, the results of which are rarely found by public health authorities. For people living in under-resourced communities, there is an incentive not to get tested at all, said Dr. Julie Vashapayan, health officer for Stanislaus County, where Modesto is located. Positive tests can be a big problem for people who can’t take time off or keep their kids out of school.

In contrast, wastewater monitoring is an efficient and relatively low-budget business that relies less on human whims. As the saying goes, everyone poops, and about 80 percent of Americans drain their solids into the sewer system.

Dozens of research projects across the country have shown that the method can be used to accurately track COVID trends over time. And because people shed Covid-19 in their feces before they developed symptoms, the rise and fall of infections at the neighborhood and community level could show up in the sludge days before testing.

Not a Modern Healthcare subscriber? Register today.

Other health problems can also leave their marks in poop.Wastewater monitoring is a reliable method, recent research finds monitor flu and Common Respiratory Disease RSV. The Centers for Disease Control and Prevention told KHN that it will soon launch a pilot study to see if sewage can reveal antibiotic-resistant infections, food-borne illnesses and Candida aurisfungal infection.

In some places, sewage may not be a good way to keep an eye on COVID. This includes communities without sewers; areas with industrial sewage, where treatment technologies can mask the virus; and communities with more volatile populations, such as ski towns.

But where available, the data has proven to be powerful.During the winter surge caused by omicron, California, Colorado, New York and Texas first detected Via sewage variant. Central Valley health officials said sewage monitoring reassured them that the drop in COVID cases was real and not a distorted reflection of the drop in reported testing.

In Modesto, wastewater also showed that the delta variant remained the dominant strain until January, weeks after omicron took over elsewhere. That’s important, Vaishampayan said, because some of the available treatments that don’t work with omicron work with delta. Her department told local doctors to keep using a variety of drugs, even after other regions had shrunk their treatment arsenal.

Getting academic researchers up and running with the program made the effort possible, said Kristynn Sullivan, chief epidemiologist for Merced County, which is building two testing sites. “We’re theoretically interested in it, but have absolutely no resources to pursue it,” Sullivan said. “What this allows us to do is step into the cutting edge, which is exciting, with fairly limited participation.”

Sullivan said it was the first time in her public health career that money was not the department’s limit. What it lacks most is people: In addition to being understaffed after years of budget cuts, Sullivan said the region is also struggling to recruit workers, a problem common to rural health departments across the country.

Norton, an engineering professor who helped set up a surveillance program in the northern Central Valley, said the setup required considerable effort. It involves coordinating sampling equipment; arranging refrigerators, coolers and ice cubes to hold samples; navigating paperwork gridlock; coordinating couriers; and the complex analysis needed to translate sludge sampling results into population infection data.

in a Recently published papers, Naughton and colleagues found that urban areas in California are more likely to have wastewater monitoring than rural communities. Through a surveillance network she has built with colleagues at UC Davis, including eight new Central Valley sites, Norton hopes to help change that. cooperate Paid by state and federal grants, CARES Act funds and charitable contributions.

Nearly 700 sites in three-quarters of states are reporting data to the government National Wastewater Monitoring System Established by the CDC and includes more than 30 California sites. However, in many states, the data is sparse and sporadic.Experts worry CDC dashboard could be misinterpreted because it only reflects percent change in virus testing limited context.

Still, having the national network will be crucial, health officials said, as researchers turn raw data into usable information and compare trends across regions. But it takes continued public will and some upgrades to keep it useful, a reality that keeps them from getting too excited about its prospects.

Funding support for the CDC program through 2025. The Central Valley program has one year of funding, although researchers hope the project will continue until at least 2023.

In Modesto, utility workers say they’re happy to tap into poop supplies as long as money flows. “I love seeing the data in use,” said Ben Koehler, the city’s water quality control supervisor and chief plant operator. “People want to know that their work has a purpose.”

Kaiser Health News is a national health policy news service. It is an independent editorial project of the Henry J. Kaiser Family Foundation, which is not affiliated with Kaiser Permanente.