The first patient traveled to Italy in mid-February. A travel companion of his was later diagnosed with COVID-19, the disease caused by the new coronavirus. The patient arrived at Denver International Airport on Feb. 29. He did not show symptoms while traveling, meaning there was a low chance of transmission in the plane and at the airport, state health officials said.

"Therefore there is no reason at this time to believe that other travelers were exposed per current CDC guidelines," Gov. Jared Polis said at a press conference.

The patient then traveled in a rental car to Summit County, where he met with friends from Colorado. They all stayed in the same condo in Summit County as part of a ski trip. He skied at Keystone and Vail resorts, both before experiencing symptoms, Vail Resorts said. The Coloradans are currently under quarantine orders in Denver.

Summit County has identified the condo unit and said no other guests have checked into it since the infected person's departure.

The patient first developed symptoms on March 3, and he went to St. Anthony's Summit Medical Center in Frisco. A sample was taken on March 4 and the test came back positive on March 5. The patient, wearing a mask, traveled to Jefferson County in a private vehicle to remain at a lower elevation. The patient's partner traveled with him and is also under quarantine.

Polis said the patient would likely be in isolation for at least 14 to 21 days.

"The patient's travel did not put many others at risk," said state epidemiologist Rachel Herlihy. The state is working to contact everyone who may have come in contact with the patient to quarantine them.

The Denver Department of Public Health and Environment is keeping the first patient's travel companions under a two-week quarantine order, accounting for the full 14-day incubation period of COVID-19. The two are not symptomatic and will not be tested until they display symptoms.

DDPHE says people under quarantine orders are instructed to stay at home and avoid school, work and public transportation. They are not allowed to have visitors and will get contacted by public health staff daily.