Colorado’s COVID hospitalizations keep rising, while flu and RSV stay low

COVID-19 hospitalizations across Colorado have increased steadily since August and are nearly at their highest point of 2023, though there are indications this latest wave — which is much smaller than earlier surges — could be starting to wane.

At the same time, the season doesn’t appear to have started in earnest locally for the other major respiratory viruses.

Data from the Colorado Department of Public Health and Environment showed 257 people statewide were hospitalized with COVID-19 as of Tuesday, up from 236 a week earlier — and a nearly 360% increase since this year’s low point on Aug. 1.

Still, that’s significantly fewer than when more than 1,500 people were hospitalized with COVID-19 during each of the pandemic’s largest spikes in December 2020, November 2021 and January 2022.

It’s possible some of the current COVID-19 patients were admitted for other reasons and tested positive, but since hospitals no longer routinely test everyone for the virus, that’s likely not driving the current increase.

The number of people receiving hospital care for COVID-19 was at its highest level in 2023 during the first week of January. In the fall of 2022, COVID-19 hospitalizations peaked at 440 during a wave that crested in late November.

There is some indication that COVID-19 may have peaked for now, because emergency department visits for the virus are down somewhat from mid-October, said Dr. Thomas Campbell, a professor of medicine in the infectious diseases division at the University of Colorado’s Anschutz Medical Campus.

With new variants continuing to emerge and immunity waning, however, it’s likely we’ll see more of the virus in the coming months, he said.

“I would expect that even if this current COVID wave is declining, we’ll have another COVID wave this winter,” Campbell said.

Unlike last year, there isn’t much activity from flu and respiratory syncytial virus in Colorado yet. In the week starting Oct. 22, the state health department reported 17 hospitalizations for flu and 19 for RSV. Both were down slightly from the prior week, though that may reflect incomplete data.

In Colorado, respiratory viruses accounted for about 2.8% of emergency department visits as of Oct. 21, with the majority of those attributed to COVID-19, according to the Centers for Disease Control and Prevention. In comparison, about 11% of emergency room visits in Colorado were for respiratory viruses at the worst point last November.

Nationwide, the percentage of emergency department visits for respiratory viruses was comparable to Colorado’s, though COVID-19 accounted for a lower percentage of visits.

Last year, flu activity started unusually early. The early circulation may have contributed to a higher hospitalization rate among children and teens, because more people got infected before receiving the vaccine than in a typical year, according to the CDC. This year, it looks like the season won’t peak until December or January, Campbell said.