– PHOTOS: Documenting COVID-19 in the Pikes Peak region.

Stopping the spread of the coronavirus is difficult because up to half of the community transmission is by people who have no symptoms, the head of Colorado’s health department said in a news briefing Thursday. 

“That’s what really made it tricky” when it comes to attempting to halt the spread of the virus at nursing homes and long-term care facilities, said Jill Hunsaker Ryan, the executive director of the Colorado Department of Public Health and Environment. 

Officials also discussed what contact tracing — contacting everyone an infected person may have exposed to the disease — might look like under Gov. Jared Polis’ “safer-at-home” phase Sunday when his “stay-at-home” order expires.

The state will use a three-pronged approach to contact tracing that will include hiring “COVID navigators” to help those who have been diagnosed or who are awaiting testing stay at home safely, and using technology. State officials said earlier this month that personal data from cellphones may be collected to trace the recent movement of those diagnosed with the virus.

As of Thursday afternoon, 552 Coloradans had died of the virus — 55 of them in El Paso County, the state’s data show. More than 11,260 have tested positive for the disease, and 873 remain hospitalized, according to 88% of Colorado’s hospitals that reported to the state department. Hospitals also reported that 77 coronavirus patients have been discharged or transferred to lower-level care since Wednesday afternoon.

The additional 44 deaths reported statewide Thursday were attributed to a change in how the state records coronavirus deaths, the state department said. Colorado’s death tally will now include “probable” coronavirus deaths, too, it said.

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Additionally, Colorado’s public health department will begin providing coronavirus death data by the date of death, instead of by the day the department received the information, a statement said. Officials have reiterated for weeks that when older data is added to the state’s website, it can appear as false “spikes” in the daily number of deaths and new cases.“The state obtains death data from a variety of sources,” the department’s statement said. “Health care providers, coroners, and local public health all report directly to the state’s epidemiology and surveillance team. The state also receives data through death certificate information. After a death, the state generally receives death certificate information within three days.”

Officials warned that lag time between when a person dies and when the state receives their death certificate could still create a delay in reporting the coronavirus death toll.

Science, data and modeling, the governor said at a news conference Wednesday, is largely what motivated state officials to move Colorado into the safer-at-home phase instead of extending the stay-at-home order.

Polis tweeted Thursday morning a slide of the presentation used in his news conference explaining what a safer at home stage looks like for Colorado.

“I want to reiterate,” the governor said, “the safer-at-home phase is not going back to life as normal.”

In the next phase of Colorado’s fight against the coronavirus, vulnerable populations must still stay at home like they did during the stay-at-home order, the governor said. Group gatherings of more than 10 people are still banned, nightclubs, gyms and spas will remain closed, and personal services such as salons and personal training will reopen with strict precautions. Critical businesses will remain open, and retail businesses can open for curbside pickup, Polis said.

Restaurants and bars will remain closed to in-person dining, he said. Elective medical and dental procedures can begin with strict precautions, Polis said. Commercial offices can staff half their employees in-person, but are still encouraged to use as much telecommuting as possible.

Hunsaker Ryan also discussed options for communities that think greater or fewer restrictions are appropriate, based on local levels of disease transmission and hospital capacity.

Local officials are able to issue their own stay-at-home orders if community transmission is high, she said. Community officials who wish for fewer restrictions are able to submit a plan to the state that includes specific triggers for instituting tighter restrictions, she added.

In other news Thursday:

• Four residents and three staff members at Pikes Peak Care Center, at 2179 N. Union Blvd., tested positive for the virus, according to data from the El Paso County Public Health. No deaths at the nursing home were reported.

The nursing home is following guidelines from the CDC and Centers for Medicare and Medicaid Services to help mitigate risk to its patients and staff, said Dr. Richard Feifer, chief medical officer for the center, in a written statement.

Feifer said Pikes Peak Care Center has been “proactive” in curbing the virus among patients and staff. Last week, the Colorado National Guard tested its residents and staff, when only one resident and one employee had previously tested positive, he said. The additional testing showed that three residents, who showed no symptoms, were infected. All four infected residents are being isolated within the center.

In total, 24 residents at long-term care facilities across the county have died due to the virus, data shows.

• The state is receiving shipments of personal protective equipment every day, and those supplies are being pushed out to “partners,” said Sarah Tuneberg, director of the state’s coronavirus Innovation Response Team.

• State and local health agencies will be running coronavirus tests at the county level, with a goal of several thousand per day, said Scott Bookman, incident commander for state’s coronavirus response. He gave no further details.

Officials had previously said that the reopening of the state would involve large-scale testing involving at least one site in each county, but the governor’s safer-at-home phase does not appear to involve mass testing, per information released this week.

• Residents of Colorado are being asked not to travel outside their county unless the travel is necessary or for work, and some neighboring states are giving similar guidance, Hunsaker Ryan said. “A regional approach … is the best way to go,” she added.

Olivia Prentzel contributed to this report.