Wastewater sampling could predict new disease outbreaks and the emergence of new variants of pathogens weeks or months before they become widespread, new research shows.
Pathogen monitoring in sewer systems, including on airplanes, can reveal which viruses and bacteria are present and cause outbreaks, two studies indicate.
Wastewater monitoring is not invasive – it does not require swabbing any people or animals – and it can detect what’s happening in places like nature reserves and farms without doing extensive monitoring at those sites, which is particularly useful during outbreaks like the H5N1 bird flu outbreak, which continues to gain speed.
Looking back at wastewater samples, researchers detected the presence of bird flu in 2022 six weeks before the virus was detected in poultry and seven weeks before it was discovered in wild bird populations, according to research published last week by the US Centers for Disease Control and Prevention (CDC).
The study analyzed 551 flu A samples detected in Oregon between September 2021 and July 2024 and found traces of bird flu in 12 communities during that time – sometimes before outbreaks were detected.
Another study, published in Nature in February, showed that analyzing the wastewater of planes at airports around the world could catch the next pandemic as much as two months earlier than current monitoring systems, the researchers said.
The researchers’ model indicated that monitoring only 20 airports serving as international and domestic hubs for flights could effectively map where new illnesses are emerging and spreading.
Testing wastewater is “more efficient than what we currently have, that is mostly testing people at the borders or trying to test in hospitals, but in a way that we are always late”, said Alessandro Vespignani, professor of computer and health sciences at Northeastern University and co-author of the Nature study.
Wastewater is faster and does not require swabbing all travelers – and it can detect new Covid variants, for example, up to two months earlier, he said.
Tracking wastewater is “definitely going to be a major improvement” for tracking ongoing and emerging outbreaks, said Marc Johnson, a professor at the University of Missouri School of Medicine and the lab lead for wastewater surveillance in Missouri.
“I envision a time when cities basically can get a report card of what’s going on in their community,” Johnson said. “If there’s something out of kilter, you’ll know. If there’s some new virus circulating, you’ll know.”
Doctors might have more specific readouts of what viruses and bacteria are circulating in their communities, so they would know what to look for in exam rooms, he said.
Among people who analyze wastewater, there has been a call to standardize how samples are collected and analyzed.
“The more it is standardized, the easier it will be to draw direct comparisons between different places,” Johnson said. “It’s going to be hard, though. We have the CDC, but really, we have 50 states that each have their own health departments that make their own decisions.”
Setting up a global system would help track pathogens as soon as they emerge. Officials can also look back at archived samples, as the CDC researchers did in the report last week, to see if a variant arrived in recent weeks or months.
Yet the Trump administration has halted federal and international funding for research and fired many employees tasked with tracking outbreaks.
Trump has also announced his intention to withdraw from the World Health Organization, which means the US would be further isolated from global experts tracking and responding to disease outbreaks.
“This kind of study is a testament to the fact that international collaboration is crucial,” Vespignani said. “There is no border for viruses, and if we want to have a good grasp on the circulation of pathogens, we need to work collaboratively in the international community. There is no other way to do that.”
Wastewater monitoring was “the next generation” approach for understanding infectious diseases, Vespignani said, before adding: “Our effort is towards not being blindsided by another pathogen in the future.”
