LISTENING TO OUR GUTS

Can wastewater surveillance help prevent the next pandemic?

- JACKIE FLYNN MOGENSEN

ONCE THE CORONAVIRUS made its human debut, it wasn't long before scientists found the virus in our poop. Fecal samples from the earliest patients, including the first known case in America, revealed people were shedding the virus not only from their noses and mouths, but also through their excrement. This would turn out to be a pivotal discovery: If the virus was in our waste, it had to be in the sewers, too. And the sewers, scientists hoped, held information about how the virus was spreading, Guy H. Palmer, a professor of pathology and infectious diseases at Washington State University, told me. "They started saying, 'We know this is in the wastewater. Can we measure it?"

The answer was a resounding yes. By sampling sewage, scientists discovered they could estimate Covid trends across communities with stunning accuracy.

"Wastewater surveillance"-the practice of monitoring sewage for pathogens, contaminants, or drugs-has since become a game-changer in the fight against Covid, particularly as at-home testing has eclipsed testing in clinics. As Palmer and his colleagues noted in a recent 151-page report for the National Academies of Sciences, Engineering, and Medicine, dozens of cities and states across the US have used sewer data to track Covid outbreaks, identify hotspots for vaccination outreach, decide where to allocate treatments like monoclonal antibodies, and serve as an early alarm for individual communities like schools or universities. In other words, the data contained in our poop has likely saved lives.