Two studies published Thursday by the Centers for Disease Control and Prevention show that wastewater surveillance detected measles outbreaks weeks to months before clinical diagnoses in Colorado and Oregon, adding to evidence that sewer testing is a powerful early-warning tool for public health officials — findings that arrive as a Trump administration budget proposal would cut the national program’s funding by roughly 80 percent.
The research underscores the value of a surveillance system that has tracked COVID-19, polio, mpox, and bird flu since 2020 and that state health officials say they cannot sustain without federal support.
Colorado and Oregon studies show early detection weeks ahead
In Colorado’s Mesa County, wastewater tested positive for measles about one week before two residents were diagnosed by a physician in August. Neither patient knew they had been exposed to the virus. As health officials traced 225 household and health-care contacts of the first two patients, they identified five additional cases.
Colorado health officials had begun testing wastewater for measles in May, as outbreaks were growing in Texas, New Mexico, and Utah and five cases had been confirmed in Colorado.
The Oregon study drew on preserved sewage samples from late 2024 to reconstruct what earlier detection would have looked like ahead of a 30-case outbreak spanning two counties. The outbreak hit a close-knit community with low rates of health-care use; the first case was confirmed July 11 and it took health officials 15 weeks to stop the spread.
Researchers found wastewater from the area tested positive for measles approximately 10 weeks before the first case was reported. The concentration of the virus in the sewage over the following weeks also matched the known peak of the outbreak.
“We knew that we were missing cases, and I think that’s always the case in measles outbreaks,” said Dr. Melissa Sutton of the Oregon Health Authority. “But this gave us an insight into how much silent transmission was occurring without us knowing about it and without our health care system knowing about it.”
National system covers 147 million people — and faces deep cuts
The national wastewater surveillance system has been run by the CDC since 2020. It now covers more than 1,300 treatment sites serving 147 million people and includes six regional centers of excellence — Colorado among them — that help other states expand their programs.
A Trump administration budget proposal would cut annual funding for the system from about $125 million to about $25 million.
Peggy Honein, director of the CDC’s division of infectious disease readiness and innovation, said the proposed level would “sustain some of the most critical activities” but “it would likely require some prioritization.”
Most state programs are entirely federally funded, Honein said. Congress has begun pushing back against cuts to health care broadly, and the budget proposal has not been enacted. But state health departments say they are preparing for potential federal funding loss regardless.
States say federal support is not replaceable
Colorado started its wastewater surveillance program in 2020 and has since expanded to cover more diseases, even as it narrowed its operational focus because the program is entirely federally funded. Allison Wheeler, manager of the state’s wastewater surveillance unit, said current funding runs through 2029 and her department is in talks with state leaders about what follows.
“I know that there are other states that haven’t been as fortunate as us,” Wheeler said. “They need this funding in order to sustain their program for the next year.”
In New Mexico, where 100 people contracted measles and one died in the prior year, the system provided a critical early warning. Wastewater monitoring flagged measles activity in northwestern Sandoval County while officials were focused on a separate, massive outbreak 300 miles away in the southeast, according to Kelley Plymesser of the state health department. The alert allowed officials to notify doctors and the public, lower testing thresholds, and redirect resources. That outbreak ended in September.
Utah has integrated wastewater data into a public-facing measles dashboard that allows anyone to track outbreaks in real time.
Sutton said she is hopeful federal leaders will recognize what the system offers.
“The widespread use of wastewater surveillance in the United States is one of the greatest advancements in communicable disease surveillance in a generation,” she said.