El Paso County could be on its way to successfully, and sustainably, suppressing the spread of the novel coronavirus into early summer, modeling from the Children's Hospital of Philadelphia's PolicyLab suggests.
As of Friday, El Paso County was running 29 new cases per day, according to data from the El Paso County Public Health Department. If residents maintain the same level of social distancing they currently are — about 40% — researchers at PolicyLab predict the number of daily new cases could drop as low as eight per day by mid-June.
"Utilizing data from a variety of publicly available sources, the researchers built their model to observe how social distancing, population density, daily temperatures, and humidity affect the number and spread of COVID-19 infections over time across a county, accounting for population characteristics, such as age, insurance status, crowding within homes and diabetes prevalence," a PolicyLab statement said.
Even at the current rate, the spread of the virus in El Paso County still pales in comparison to hot spots across the state, including Denver, where there are roughly 704 confirmed cases per 100,000, according to data from the Colorado Department of Public Health and Environment. As of Friday, the case rate per 100,000 people in El Paso County is about 202, said county health spokeswoman Michelle Hewitt. The fatality rate is 12 per 100,000, she said.
PolicyLab's model estimated Denver County would see a plateau at about 113 daily cases by mid-June, if residents maintained their current 61% level of social distancing.
Still, "in many ways, Colorado could lead the nation" at practicing a sustainable way of living with the virus, said Dr. David Rubin, director of the PolicyLab.
"When I look at (El Paso County's) reproduction numbers and risk of resurgence, it's low right now," Rubin said. "I suspect it's because of that individual vigilance."
The organization analyzed hundreds of counties across the country, including 10 in Colorado.
"We're seeing the resurgence risk in areas that may have overreached," Rubin said. "But we're also seeing places like Colorado Springs and Denver that look like, at least for the time being, that the individual behavior and that social contact people have with each other seems to be holding up really well. You guys are finding what I think is the new normal."
But the positive outlook comes at a risk, he added. Predictive modeling has been a hot topic in the media since the novel coronavirus outbreak, and predicting a decline in new cases could cause complacency, Rubin warned.
"The message this week to Denver and Colorado Springs is: Keep up the great work and don't get complacent," he said. "You're figuring out just exactly what you need to do to contain this virus."
Modeling is notoriously tricky, and can set dangerous expectations for people who don't know how often they change. In fact, models can change on a daily basis, El Paso County public health officials said Friday.
The further out the predictions are, the weaker the data becomes, said Fadi Youkhana, an epidemiologist with county health.
"Models should not be used as a measuring stick but rather as supplemental information," Youkhana wrote in an email. "Models are not the 'end-all-be-all' but rather tools that we can utilize to stay informed. At the end of the day, the most important thing for us to do is abide by the social distancing guidelines."
Models for SARS-CoV-2 — the scientific name for the new coronavirus — are highly dependent on variables such as population density and social behaviors, said Stephen Goodwin, county public health's data guru. El Paso County is significantly less dense in population than Denver, he said.
"The fundamentals of the spread, we know about," Goodwin said. "The question is our collective behavior and people's ability to judge risk and make personal choices."
"We do know that a contributing factor is the general positive response and the adherence to our recommendations from our El Paso County residents," Youkhana added.
The first COVID-19 death in the state was in Colorado Springs, Goodwin pointed out. It's possible that changed the behavior of people in the more vulnerable age groups, he said.
There are also theories that warmer weather will help slow the spread of the virus, which can be true for any respiratory illness, said Dr. David Steinbruner, associate chief medical officer for UCHealth.
"What appears to be the case, is it doesn't do well in ultraviolet light and it doesn't do well in drier climates," Steinbruner said. That doesn't mean it won't continue to spread, he said.
Summertime also offers new opportunities for people to spread out more, county health officials said. Viruses in general are more fragile outdoors, they said.
Health care officials often feel "cautious optimism" when new models arise, Steinbruner noted.
"All of us are trying to drive this with the science," he said. "Any time we get new information we're always taking it with a bit of a grain of salt. ... We're trying to process a tremendous amount of information over a short period of time."
"Pace yourself and keep up the good work," Steinbruner said. "We're not out of the woods yet."