LAS VEGAS (AP) — The Las Vegas area has been added to places in Nevada where authorities have detected cases of a potentially worrisome strain of the coronavirus found in India.

A woman in her 20s who had not traveled recently and was not vaccinated against COVID-19 tested positive for a variant subtype officially known as B.1.617.2, the Southern Nevada Health District reported Tuesday.

No additional cases of the variant were reported Wednesday, district spokeswoman Jennifer Sizemore said.

The woman did not require hospital treatment, and an investigation aimed to identify people she came in contact with, the district said.

Eight other cases of the Indian variant have been identified in northern Nevada, including four confirmed last week in the Reno area, officials have said.

The India strain may spread more easily but testing to track and understand it has been slow, health authorities say.

COVID-19 vaccines currently used in the U.S. offer protection against most variants, officials say.

Dr. Mark Pandori, head of the state Public Health Laboratory at University of Nevada, Reno School of Medicine, told the Las Vegas Review-Journal that Nevada cases also were identified among people in Carson City and Churchill and Lyon counties.

Dr. Fermin Leguen, chief Southern Nevada Health District health officer, called identification of another COVID-19 variant a reminder that the pandemic isn’t over and people should continue to protect themselves and others.

In Washoe County, the four cases of the variant originating in India confirmed last week involved two men and two women whose ages range from 29 to 69. None had traveled, but one of them works at a place where they interact with travelers, the health district said.

Washoe County’s seven-day moving average for new daily COVID-19 cases has hovered in the 30s over the past week, the lowest level it has been since June.

But health officials remain concerned about variants, especially the one that originated in United Kingdom, which is the most prevalent in the county and is believed to have a transmissibility rate that is 50% to 60% higher than other strains, health district officer Kevin Dick said last week.

Nevada Gov. Steve Sisolak, a Democrat, has set a June 1 date for lifting coronavirus mitigation restrictions statewide, including eliminating all capacity caps, with the exception of a mask mandate.

State health officials on Wednesday reported 464 new cases of COVID-19 and six more deaths since Tuesday. The Department of Health and Human Services has reported almost 320,000 cases and 5,515 deaths since the pandemic began.

The 14-day test positivity rate, a measure of the number of people tested for coronavirus and found positive, was 5.4% in Nevada and 5.5% in the Las Vegas area. The World Health Organization goal is 5% or below to relax restrictions.

The Southern Nevada Health District administers Clark County, home to 2.3 million people including Las Vegas. It reported other variants of COVID-19 on Tuesday, including 242 cases of the B.1.1.7 strain identified in the United Kingdom, five cases of the B.1.351 South African strain, five cases of the California strain B.1.429 and 28 cases of the Brazilian strain, P.1.