LAS VEGAS (AP) — Health officials in Las Vegas said Thursday that the tourist destination has its first case of coronavirus — a man in his 50s who recently returned from a trip to Washington state.

The patient has been hospitalized in an isolation unit, said Dr. Fermin Leguen, acting chief of the Southern Nevada Health District, which includes the city of 2.6 million residents that draws more than 40 million visitors a year.

He said the diagnosis was made late Wednesday based on lab results after the man sought treatment for respiratory distress.

The case puts Nevada on the list of states with cases of the virus that causes COVID-19. Washington state has been hit hardest, with 11 deaths.

Nevada Gov. Steve Sisolak urged residents and tourists to remain calm and follow guidance from health officials about ways to stem the spread of the virus.

“We must all do our part to prepare and prevent – not panic," the governor said. “Nevada and our local health authorities are taking this situation very seriously and have been preparing for weeks in anticipation of a presumptive case."

Sisolak signed an emergency order prohibiting price-gouging by state-regulated health insurers or the imposition of out-of-pocket costs for insured people who visit a doctor's office, urgent care center or emergency room to be tested for the virus. He said he doesn't want medical costs associated with COVID-19 to be a barrier to virus testing and treatment.

“Additionally, the regulation prohibits insurers from charging Nevadans for the COVID-19 test itself or an immunization as one becomes available," the governor said.

Leguen, the top public health doctor in Las Vegas, said people seeking testing or treatment should call health providers first and not go directly to hospitals or emergency rooms.

Leguen declined to describe the Nevada man’s condition. He called it “hard to say” if his illness was life-threatening. Leguen also declined to identify the hospital where the patient is being treated.

Investigators are tracking down people who had contact with the man since he returned home from Washington, including family members and a school-age child. The patient also made a recent trip to Texas.

“We have not been in touch with every single person,” said Kimberly Hertin, a district health investigator.

Leguen said it appeared the man contracted the virus elsewhere, not locally. About 200 people were being monitored statewide, he said.

State epidemiologist Melissa Peek-Bullock said authorities are aiming to “identify and contain" the outbreak.

“While the first presumptive case of novel coronavirus is concerning, it is important to remember that most Nevada residents are at low risk of contracting COVID-19 at this time,” she said.

Coronavirus is part of a family of viruses that can cause a common cold or more severe diseases such as severe acute respiratory syndrome, or SARS. COVID-19 first appeared in late 2019 in Wuhan, China.

The discovery of a case of the new coronavirus in Nevada was not a surprise, said Brian Labus, assistant professor of public health at the University of Nevada, Las Vegas, and former senior epidemiologist at the health district.

“This is a tourist hub. People bring things here all the time and take things home as well,” Labus said. “It’s likely that this virus is pretty much everywhere and it just took time to find it.”

Labus said the discovery of more cases would not be a surprise.

“Think of cards and dice," he said. “You don’t know what's on a surface that someone touched before you did."

Share prices for MGM Resorts International, Caesars Entertainment, Wynn Resorts and Las Vegas Sands closed down following the announcement.

Tourism officials with the Las Vegas Convention and Visitors Authority, the Nevada Resort Association and several large casino companies declined immediate comment.