LAFAYETTE, Colo. — A substitute teacher for Centaurus High School in Lafayette is under self-quarantine after he was informed Wednesday that he was aboard a Princess Cruise ship 12 days ago with another passenger who tested positive for coronavirus.

The male substitute teacher, who had been subbing at the school for the past five days, was at the Boulder Valley School District school Wednesday when the cruise line notified him of the infected passenger, according to a district spokesperson.

After learning of the possible exposure to the virus, he immediately returned home and will remain there for the next two days to complete the recommended 14-day self-monitoring period, the district said.

The teacher, who was not identified, isn't showing any signs or symptoms of COVID-19, the disease caused by the novel coronavirus.

MORE | Tips on how to prevent catching, spreading coronavirus

It's unclear what Princess Cruise ship the teacher was aboard.

Later Wednesday evening, the Office of Natural Resources Revenue (ONRR) in Denver reported one of its employees was also under self-quarantine after a possible exposure to COVID-19.

Gov. Jared Polis said Tuesday there are no known cases of the virus or the disease that the virus causes in Colorado but that state officials are ready to respond if any are confirmed.

As of Thursday morning, 58 people in Colorado have been tested for COVID-19 in Colorado — 37 are negative while 21 are pending, according to the Colorado Department of Public Health and Environment. No tests came back positive.