Prognosis
Omicron’s Spread Through U.S. Cities Is Shown in Wastewater Study
- Sewage tests found related mutations before human cases
- Testing could help health officials get ahead of outbreaks
A researcher processes wastewater samples in Tucson, Arizona.
Photographer: Cheney Orr/BloombergThis article is for subscribers only.
Signs of the omicron variant that’s fueling a worldwide surge in Covid-19 cases were present in the U.S. a week or more before it first appeared in California, and spread widely in the weeks afterwards, according to a study showing the power of wastewater analysis for tracking outbreaks.
Evidence of omicron appeared in U.S. sewage samples collected as early as Nov. 21, state and local health officials from California, Colorado, Houston and New York City said in a study published by the U.S. Centers for Disease Control and Prevention. The first infection in a U.S. patient was confirmed on Dec. 1 in California.