LAS VEGAS (KLAS) — Data from what the Las Vegas Valley is flushing shows a deep decline in omicron, but a spike in the so-called “stealth omicron” variant, scientists at UNLV tell the 8 News Now I-Team.

Southern Nevada Water Authority scientists take samples from wastewater to see how much coronavirus is in our sewer system. Dr. Edwin Oh, an associate professor at the school’s Neurogenetics and Precision Medicine Lab, and other researchers analyze the samples, which help public health leaders find spikes and clusters before they can be identified through traditional testing methods.

In early January, data from wastewater treatment plants across southern Nevada showed coronavirus levels at all-time highs.

Scientists at UNLV first found the omicron variant in samples of wastewater in December, Oh said.

Coronavirus primarily affects our lungs, but the virus also causes secondary infections of the gastrointestinal tract. As the virus duplicates and is shed out of our bodies, some identifiable factors show up in our waste.

Recent data shows a steep decline in omicron in wastewater, but a rise in its variant. Stealth omicron has mutations that could make it more contagious and harder to detect, giving it its “stealth” name.

Leaders at the Southern Nevada Health District (SNHD) confirmed the first stealth omicron case in Clark County on Jan. 28. The woman in her 40s was fully vaccinated.

As of this week, Oh said he estimated 5% to 10% of the infected population has the stealth variant.

The good news is initial research shows no difference in hospitalization between the two variants, Oh said.

“Based on current information about the BA.2 variant, there is no evidence that it causes more severe disease than the original Omicron variant,” SNHD officials said late last month. “It is expected that new variants will occur. Reducing disease transmission through vaccination is one of the best ways to slow the emergence of new variants.”

COVID-19 cases stayed under 900 in Clark County, but 43 deaths were reported in data released Tuesday.

Clark County’s 884 new cases accounted for about 55% of the state’s total — 1,588. But the county’s 43 deaths made up 86% of the state’s total of 50 deaths.