In early 2020, not long after COVID-19 had first gripped the world, researchers from Bangor University in the United Kingdom began testing wastewater in major cities. They hypothesized that by testing wastewater for the coronavirus, it would be possible to keep tabs on the spread of the virus as it would reflect infections in that city. Their experiment was a success, spurring British scientists to refine the methods used for detecting the virus and sequencing the virus’ genome, allowing variants to be detected as well. This culminated in a national wastewater monitoring program encompassing 270 sewage treatment plants, or 40 million people.
Now, Bangor University has expanded these efforts to monitor the coronavirus infections and general health of airplane passengers coming into the UK from other countries. The new study, published in PLOS Global Public Health, yielded disappointing results: almost all planes arriving at the three monitored UK airports—Heathrow, Edinburgh, and Bristol—between March 8 and March 31, 2022 had the virus in their wastewater. “Despite all the intervention measures that the UK had in place to try to stop people with the illness getting on flights to the UK, almost every single plane we tested contained the virus, and most of the terminal sewers, too,” said professor David Jones of Bangor University’s School of Natural Sciences. “That might have been because people developed symptoms after testing negative, or were evading the system, or for some other reason. But it showed that there was essentially a failure of border control in terms of COVID surveillance.”
Based on survey data that the research team collected along with COVID-19 shedding rates, they believe that wastewater sampling systems implemented at airports could catch between eight and 14 percent of COVID-19 cases entering the UK through air travel. Additionally, the team hopes that this wastewater sampling could extend beyond the coronavirus, allowing the UK government to establish an infectious disease transmission surveillance network that can pick up a variety of viruses.