Dr Adam Lauring, a virologist at the University of Michigan who was not involved in the study, said: “To have something in the sewer that you’re detecting, you need a little bit of it.
Dr. Johnson, a Missouri virologist, agrees. He supports the hypothesis that the chains come from animals, perhaps a few specific populations with limited territories. In May and June 2021, when the number of human Covid-19 infections in the city was low, mysterious lineages accounted for a larger proportion of viral RNA in wastewater, suggesting that they may have come from a single source. not human.
The researchers initially looked at a range of potential hosts, from squirrels to skunks. “This is a very promiscuous virus,” said Dr Johnson. “It can infect all kinds of species.”
To narrow down the possibilities, they went back to wastewater, assuming that any animal shedding the virus could also leave behind its own genetic material.
Although most of the genetic material in the water comes from humans, small amounts of RNA from dogs, cats and mice are also present, the scientists found.
Dr. Johnson looked at rats, which roam the city with millions of them. In his lab, he created pseudoviruses – harmless, non-chemical viruses – with the same mutations present in cryptic sequences. He found that the pseudovirus could infect both mouse and rat cells. The original version of the virus is unlikely to infect rodents, although some other variants, like Beta, can.
“It’s not huge data by its nature, but at least it’s consistent with the idea that it came from rodents,” Dr. Johnson said.
https://www.nytimes.com/2022/02/03/health/coronavirus-wastewater-new-york.html In New York City Sewage, a Mysterious Signal of Coronavirus