Researchers at the University of Missouri have detected at least four “cryptic” variants of the coronavirus in samples of wastewater from New York City’s public sewer system, according to Science Daily.
The U.S. Centers for Disease Control and Prevention (CDC) says viruses such as the coronavirus can continually evolve by mutating. The highly transmissible variants, such as Delta or Omicron, may contain one or more mutations that help scientists to distinguish them from other variants of the virus.
Prof. Marc Johnson, the co-corresponding author of the study, said he believes the findings suggest the “cryptic” mutations identified in NYC could be linked to possible animal origins. These origins have not been verified yet, but he believes that rats could be one possible source, as they are found frequently in NYC’s sewer system.
“For instance, we still don’t know where the omicron variant came from, but it had to come from somewhere,” Prof. Johnson explained. “These variants are bubbling up everywhere, including omicron, which eventually spilled into the general population and wreaked havoc. We think these weird lineages could be where the next variant of concern for COVID-19 comes from.”
Prof. Johnson was reaching out to various scientists across the nation who were doing similar kinds of research with wastewater after he observed some unusual results from his analysis of wastewater in some samples from the greater St. Louis area.
He said, “When we first started with the samples from New York City, I was looking to see if they had the same virus sequences that I saw in some of my samples from St. Louis. They were different, but all of them had similar mutations in common at one particular location on the virus — Q498.”
“What’s amazing is that in most of the samples from New York City, the Q in Q498 had turned into a Y, or glutamine into tyrosine. If you look at the database, there was not, and continues to not be, a human patient who has had that mutation,” he added.
Experts have been hunting for virus mutations. The idea for this project started in March 2020. Prof. John Dennehy, a virologist at Queens College, City University of New York, started looking for different ways to analyze the impact of the COVID-19 pandemic.
He believes a possible explanation could be a biological process called convergent evolution, according to Science Daily.
He explained, “An animal in Missouri is not going to mix with the same type of animal in New York City. Therefore, the evolution of the virus in each geographic area is independent of each other, but because it’s the same animal, the virus looks the same in both places.”
“For instance, we think conditions in South Africa that gave rise to the omicron variant are the same conditions in New York City that gave rise to our cryptic variants,” Prof. Dennehy added. “As a biologist, I thought the spread of delta was menacing, but the speed in which omicron took over New York City is on another level.”
The researchers published the study, titled “Tracking cryptic SARS-CoV-2 lineages detected in NYC wastewater,” in the journal Nature Communications. The New York City Department of Environmental Protection provided the funding for the study.
