Tracking microbes through a malodorous network of sewer lines led virologist Marc Johnson to the source of unusual coronavirus mutants.
After months of sampling effluent, the University of Missouri School of Medicine microbiologist found exactly where the mutants originated: from a regular user of restrooms at a specific Wisconsin business. Although unable to identify that individual, Johnson could still see from genetic data that viral particles were being freshly made and expelled for more than a year — many times longer than a typical two-week COVID-19 infection.
And during that time, the mutations showed the virus was "running like hell,” trying to evade the person’s immune system, Johnson said. Laboratory analysis of his sewer samples exposed the battleground inside the patient’s body, where the virus was quickly evolving to maintain a stronghold.