A Minnesota professor has discovered the coronavirus in lake water—apparently the first such such find during the COVID-19 pandemic, the Pioneer Press reports. Richard Melvin of the University of Minnesota Medical School says he stumbled on SARS-CoV-2, which causes COVID-19, in samples culled from eight beaches along Lake Superior on the weekends of September 11 and 18. Oddly, he'd found no coronavirus while sampling the same beaches on other weekends following the Fourth of July. "Now we're entering a season where people are not entering the beach in the water and we're suddenly detecting traces of the virus," he tells KARE-11. "So, that's very interesting."
The discovery comes with caveats. His medical school says the virus appeared in levels of 100 to 1,000 copies per liter, or 10,000 times less than levels found in wastewater. And medical experts have found no evidence of the virus spreading via exposure to water. "At this time, the source or sources of the virus are unknown," the school says. Melvin notes that people can shed the coronavirus for a month after losing symptoms, so it might have come off swimmers' bodies. He adds that virus levels in lake water could be an indicator of coronavirus prevalence in communities—just as levels in wastewater have provided early evidence of outbreaks and case levels in Minnesota. (Read more coronavirus stories.)