The first omicron case was reported in the U.S. on Dec. 1, 2021 and since then has led to a wave of omicron cases nationwide. However, a new analysis of wastewater surveillance data suggests that omicron could have been spreading as early as Nov. 21.
The National Wastewater Surveillance System (NWSS) is funded by the Centers for Disease Control and Prevention (CDC) and is made up of 43 health departments. Four states, California, Colorado, New York and Texas, were the first of these health departments to detect potential omicron virus in community wastewater between the period of Nov. 21 and Dec. 16.
Viruses are broken down into pieces by the time they are in wastewater, so the health officials can only analyze fragments of the viral genome. But, they saw signs of omicron mutations in the viruses found in wastewater and this suggests that omicron may have been present in the population.