DENVER — Colorado officials have said for weeks that COVID-19 case numbers in the state are in a good place, with daily cases leveling off and testing positivity rates well below the state's benchmark of 5%.
But with Labor Day coming up, and with schools back in session, health officials on Wednesday emphasized the need to be cautious to avoid a similar bump in cases that the state saw following Fourth of July.
Officials described the July bump as Colorado's second wave of COVID-19, though more testing was in place in July than during the initial peak in April. Still, officials said Wednesday that the July rise in cases and hospitalizations showed what could happen if social distancing decreases and more large gatherings occur.
Dr. Rachel Herlihy, the state epidemiologist, and Dr. Jonathan Samet, dean of the Colorado School of Public Health, presented several modeling graphs, showing the potential effect of a Labor Day bump, coupled with in-person classes at schools and universities.
The Labor Day scenario presented Wednesday mirrored the data from the Fourth of July, with projected levels of 42% social distancing beginning now through Sept. 21. Colorado's current social distancing is at levels of 79%, officials said.
A decrease in social distancing to 42% over the Labor Day weekend and in the weeks following would cause COVID-19 cases to rise into October before leveling off again. The bump in cases would be slightly less than the July increase, and much less than the initial peak in April.
But Labor Day gatherings aren't the only risk of an increase in cases, officials said.
Another modeling graph presented Wednesday showed how a reduction in social distancing among young people could lead to more COVID-19 transmission.
At the current social distancing rate of 79%, cases would continue to drop. A 10% decrease in social distancing would still see cases generally plateau. A 20% decrease in social distancing would see cases increase slightly, and a 30% decrease in social distancing would see a large rise in cases.
Samet emphasized that the effect from a large dip in social distancing "represents an extreme value," as there's still uncertainty as to how much social distancing will be taken place in schools and how students interacts with adults, both at school and at home.
"But these kinds of projections are useful to anticipate and consider what could happen," Samet said.
A concern from the combined effect of Labor Day gatherings and schools reopening would be a rise in hospitalizations. The data presented Wednesday showed how hospitalization rates could also increase if social distancing decreases.
Herlihy and Samet said Colorado is in a better position to contain COVID-1`9, even with a decrease in social distancing, than the state was in March and April and June, when cases were already beginning to rise ahead of Fourth of July. Mask-wearing is more widespread and testing positivity rates are lower.
"We would be starting at a better place," Samet said.
Many Colorado school districts started classes over the past week. Some larger districts, such Denver Public Schools, have started the year with remote classes, while others are doing a hybrid model of in-person and remote learning.
At the college level, Colorado universities have held in-person classes, though some issues have popped up. At CU Boulder, university officials are cracking down on parties and other large gatherings.
In Colorado Springs, 10 positive cases at Colorado College led to the school this week going fully remote for at least the next several weeks and possible for the rest of the fall semester.