LAS VEGAS (KLAS) — A study from smart thermometer company Kinsa Health finds the spread of coronavirus across the Southwest U.S. may be attributed to visits to Las Vegas, the company wrote Tuesday.

“Travel to Las Vegas in recent months and a new coronavirus variant have likely contributed to the rapid, regional spread of cases across southern California, Arizona and Nevada,” the company wrote on its Health Weather website. “The data also shows strong correlations between the sickest counties and higher rates of travel to businesses along the Las Vegas Strip after New Year’s, as well as earlier in December, when the new variant took hold.”

The B.1.1.7 variant, first detected in the United Kingdom, was found in a sample in Nevada last week, researchers announced Monday. The variant is more contagious than the one first discovered in Wuhan, China.

Kinsa’s 2 million smart thermometers send anonymous data back to researchers to track spikes in fevers, which can help health leaders track the spread of disease.

“Generally, fever is a common symptom of COVID-19, and we can see that days or up to weeks before COVID-19 cases increase,” Kinsa’s director of communications, Jane Putnam, said. “It’s a leading indicator of where increases are going to be.”

Kinsa researchers noted a correlation between communities in southern California with high rates of COVID-19 spread and travel to Las Vegas.

“An analysis of Kinsa’s daily illness data, which shows fluctuations in fevers weeks before test results are reported and is not affected by variations in testing regimes across state lines, shows that the southern California outbreak coincided with a similar spike in the southern half of Nevada and much of Arizona,” Kinsa researchers wrote.

“Residents of the affected counties in California, Arizona and Nevada were up to twice as likely to have traveled to businesses on the Las Vegas Strip in December and January, according to an analysis of anonymized cellphone location data from SafeGraph,” Kinsa reported.

Nevada Gov. Steve Sisolak had asked Nevadans to stay in for New Year’s Eve, but hundreds ignored this, packing the Strip. While there were no fireworks on the Strip to celebrate 2021, the county did close part of the road to traffic.

Cases in Nevada appear to be dropping from mid-January highs. For the second day in a row, the state reported less than 1,000 new virus infections in the past 24 hours.