Summit County Public Health is investigating an outbreak of three cases of the novel coronavirus among employees of Mountain Temp Services and Ardani Inc.

The two companies manage housekeeping services for hospitality businesses throughout the county. The three employees were providing housekeeping services at Vacasa Vacation Rentals at Main Street Station in Breckenridge when they tested positive, according to a news release from the county.

The outbreak is the fourth the county has reported since Saturday, Sept. 19. While Mountain Temp Services and Ardani, Inc. are responsible for hiring and HR duties, Vacasa was in charge of scheduling the employees. The county found that Vacasa had not been screening employees prior to work, according to the news release.

The three employees had been carpooling to work together. There was no significant exposure to vacation rental guests, according to the release.

The county’s contact tracing team is still determining close contacts of the three positive cases. According to the release, one of the people who tested positive has not been willing to share close contacts.

All three of the employees have been isolated and all close contacts that the county has identified are in quarantine.

Vacasa has been extremely cooperative with public health in discussions of sanitation procedures and implementing a system for screening employees, according to the release.