Omicron variant takes command in Southern Nevada, researchers say

Las Vegas researchers predict that most news cases of COVID-19 in Southern Nevada for at least the next three weeks will be caused by the more contagious but seemingly milder omicron variant.

The researchers predict that eight or nine of every 10 new cases will be caused by omicron, based on a genetic analysis of local wastewater, said Edwin Oh, an associate professor of neurogenetics at UNLV.

Oh said that he and researcher Dan Gerrity, a microbiologist with the Southern Nevada Water Authority, are seeing the highest levels of the new coronavirus to date in Las Vegas Valley wastewater. The researchers analyze levels and strains of the virus, which passes through the body and appears in sewage.

With coronavirus levels at “all-time highs” in wastewater, “we worry that we are also going to see case numbers that we have never seen before,” Oh said in an email.

The researcher’s analysis comes as COVID-19 case numbers are soaring locally, across the country and around the globe.

Ongoing research will show whether strains mutating from delta, which has been the dominant variant and is associated with more serious illness, will disappear as omicron becomes more prevalent. Data out of South Africa — where omicron was first identified — the U.K. and now the U.S. suggests that omicron is less likely than delta to lead to hospitalization and death.

Genetic analysis of wastewater can detect that a new variant is emerging a week or even a month before a similar analysis of samples of positive COVID-19 test results in public health laboratories, Oh said.

Omicron, first detected in a Nevada test sample on Dec. 14, had been detected in wastewater a week earlier, he said. The alpha and epsilon variants were spotted in wastewater a month before actual cases were identified.

Genetic analysis of COVID-19 test samples over the past five days by the Nevada State Public Health Laboratory in Reno found that 58 percent of cases were the omicron variant, and 38 percent the delta variant and strains that had evolved from delta. Meanwhile, at one wastewater site in Las Vegas, omicron recently accounted for 95 percent of the virus detected.

The research also will help in understanding how the virus continues to evolve.

“A question moving forward is how will omicron mutate, and wastewater surveillance will help us determine this answer,” Oh said.

Contact Mary Hynes at mhynes@reviewjournal.com or 702-383-0336. Follow @MaryHynes1 on Twitter.