The rate at which COVID-19 is being spread in Colorado has dropped by nearly half in the past few weeks, an encouraging sign as health officials try to stem a resurgence of the potentially fatal disease.
The average number of people who will catch the disease from a single infected person — known as the reproductive rate or R0 — was down to 1 on Friday, state health officials reported, meaning the disease had essentially been halted for the time being.
That was an improvement from mid-July when it was at 1.8, according to the University of Colorado, and a vast difference from the spring when it was between 3 and 4 and spreading rapidly.
"We are seeing a stabilization in hospitalizations occurring and a stabilization in the percentage of positives, in some ways, depending on how you look at case counts," said Dr. Rachel Herlihy, a state health department epidemiologist. "It's great news for us and reassuring to see."
Nevertheless, officials remain wary because Colorado is right on the borderline — if the rate rises above 1 again, the state will see an increase in cases as the disease resumes spreading.
Herlihy cautioned that while the rate has plateaued, the number could go either way. It's still possible to see a "rapid increase" in cases if Coloradans relax social distancing practices and stop wearing masks, she said.
It isn't possible to pinpoint any one reason for the decline in the rate, Herlihy said. But it's likely due to a combination of public health measures, including the governor's mask mandate, issued July 16; the shutting down of bars again, announced June 30; and the governor decreeing a 10 p.m. last call for serving alcohol, issued July 21.
The drop also likely means more people are adhering to social distancing recommendations, she said.
Based on cellphone data, nearly three-quarters of the state's population is following advice on staying 6 feet apart in public, up nearly 20% from earlier in July, state health officials said. It had peaked at nearly 90% during May, according to state data.