LAS VEGAS – Three new coronavirus cases in Nevada include a New York woman in her 40s who attended a large conference on the Las Vegas Strip.

The hospitalized patient attended the Women in Power Summit from March 5-8 at the Mirage. She had had been exhibiting symptoms of COVID-19 during her travels to Las Vegas, according to the Southern Nevada Health District.

The health district said it is working with the Mirage and organizers of the summit to inform attendees and identify people who came in close contact with the individual.

There were more than 1,000 registered attendees. Officials are investigating if the woman visited any other properties on the strip.

“We want to know every single detail about where she had been during those days,” said Fermin Leguen, district health officer for the Southern Nevada Health District.

On Wednesday, MGM Resorts International informed guests and employees that the Southern Nevada Health District has confirmed a COVID-19 case involving a guest at The Mirage.

"Upon learning of the individual’s symptoms, Mirage staff worked in coordination with the state health district to implement MGM Resorts’ health and safety protocol," MGM Resorts said in a statement.

Access to hotel room restricted

The company is coordinating with the Southern Nevada Health District to notify guests and employees who may have had close, prolonged contact with the patient. MGM is directing employees to follow all 14-day, self-quarantine requests.

MGM Resorts has deployed professional cleaners to sanitize the patient's room and eliminate the virus, the company said.

"Access to the room remains restricted as it undergoes this comprehensive cleaning and disinfectant process," the statement said.

Buffets to close this weekend

MGM Resorts will close buffets at seven Strip properties this weekend due to coronavirus concerns: ARIA, Bellagio, MGM Grand, Mandalay Bay, The Mirage, Luxor and Excalibur. Closures begin March 15.

"These changes are temporary and will be evaluated on a weekly basis," the company said in a statement to the USA TODAY Network.

Spread of the infection has also changed buffet procedures at Wynn Las Vegas. The buffet is now using culinary staff serve guests – eliminating the need for guests to touch serving utensils.

“In addition, we are routinely cleaning all hard surfaces and have placed hand sanitizing stations at the entrance for guests to utilize prior to entry,” Wynn spokesperson Jesse Williams said in a statement. “All of our restaurants continue to maintain the highest possible standards of cleanliness.”

Properties of Caesars Entertainment – the largest MGM competitor on the Strip – will keep buffets open.

"We are incorporating cleaning and hygiene protocols into the buffets as well as the rest of our operations across the company," the company said in a statement.

Total cases in Nevada: 7

Health officials announced three new cases of presumptive COVID-19 in Clark County Wednesday afternoon, bringing the total number of cases in Nevada to seven.

Along with the woman who stayed at the Mirage, two others tested positive after close contact with a previously reported case: A male in his 60s and a woman in her 70s both isolating at home.

As testing continues, Leguen said the testing lab in southern Nevada has capacity for about 100 tests on hand and another 800 on the way.

Where is the coronavirus?:Interactive map shows cases in Nevada and beyond