Colorado’s latest surge of coronavirus cases appears to have stabilized as a statewide mask mandate and limitations on serving alcohol take hold, state health leaders said Friday.
Jill Hunsaker Ryan, the head of the Colorado Department of Public Health and Environment, said the latest data appear to show that the reproduction value for the virus — the average number of people that an infected person passes the virus onto, also known as the R0 — has dropped to 1. If further data bear that out, it means Colorado is no longer experiencing exponential growth of cases and the horror scenario of overwhelmed hospitals will be avoided.
COVID-19 IN COLORADO
The latest from the coronavirus outbreak in Colorado:
- MAP: Cases and deaths in Colorado.
- TESTING: Here’s where to find a community testing site. The state is now encouraging anyone with symptoms to get tested.
- VACCINE HOTLINE: Get up-to-date information.
“That is absolutely great news for us and reassuring to see,” said Dr. Rachel Herlihy, the state epidemiologist at CDPHE.
As recently as a couple weeks ago, the R0 had been around 1.7 — meaning that a single case could lead to more than 280 additional infections within a month or two. But Herlihy said the latest numbers show stabilization in both the number of people hospitalized with COVID-19 and the proportion of tests that come back positive. The state also appears to be past its latest peak in newly reported coronavirus infections, she said. Last week, Colorado reported its highest-ever weekly total of new COVID-19 cases, fueled mostly by rising infections among younger adults.
“Colorado is at an interesting point,” Dr. Jonathan Samet, the dean of the Colorado School of Public Health and the leader of a team of researchers providing modeling predictions for the course of the pandemic in the state, said Thursday during a Q&A session with The Colorado Sun and the Mountain West News Bureau.
“We’re heading into August at a seeming stable point where things aren’t either going up or down. They’re either going to do one or the other as the weeks go on. … I think we’re at least at a point where we’re not on a surge as we look at schools opening in a couple of weeks.”

Herlihy said there is no single reason for the case stabilization, but it comes after Gov. Jared Polis, under increasing scrutiny for his aggressive strategy to reopen the state’s economy, issued multiple orders rolling back that reopening.
On June 30, Polis ordered bars and nightclubs to close again. On July 16, Polis issued a statewide mandate to wear face masks when indoors in public. And on July 21, with cases still rising, Polis ordered alcohol sales to cease at 10 p.m. hoping to prevent boozy late-night lapses in social distancing.
It takes about two weeks for a policy intervention to start showing results in the state’s case data, health experts have said. And, in addition to Polis’ orders, it’s also possible that attention paid to Colorado’s increasing number of infections caused more people to stay home or that other factors are at work.
“Coloradans are doing the right thing,” Polis said Thursday. “Coloradans are smart. I think we’re seeing the impact from two changes that is showing up now.”
Still, while stopping the rise in coronavirus infections is a good thing, Herlihy said the state needs to work to bring the R0 below 1 — at which point the virus would gradually peter out in the state. If Coloradans relax at this point, cases could just as easily explode upward again.
“We still are at a bit of a tenuous place,” she said.
Bob McDonald, the head of the Denver Department of Public Health and Environment, said for that reason, authorities in his city will step up enforcement of the mask mandate over the weekend.
“This thing could boil over at any point in time,” he said. “We need to be diligent.”