Colorado’s COVID hospitalizations remain stable despite new variant taking over

Severe COVID-19 infections in Colorado are roughly stable for now, despite continued winter weather and a new variant becoming dominant.

The Colorado Department of Public Health and Environment reported 186 people were hospitalized with the virus statewide as of Tuesday afternoon — virtually unchanged from 192 a week earlier.

Viral concentrations in wastewater may be increasing slightly, which would point to increasing infections, but the overall picture is one of stability, said Dr. Jon Samet, dean of the Colorado School of Public Health. Hospitalizations are generally trending down nationwide, with a few exceptions, he said.

“We’re at some sort of point like we’ve seen before, where we’ve come to rest,” he said.

It’s good news that Colorado and the country aren’t seeing a surge like they did the last two winters, Samet said. And while much remains unknown about the XBB.1.5 variant — yet another descendant of omicron — it hasn’t produced a large wave as it has taken over, he said.

XBB.1.5 caused about 80% of cases nationwide and 75% in the region including Colorado in the most recent week, according to estimates from the Centers for Disease Control and Prevention.

The relatively low level of severe infections likely reflects that most people have immunity from vaccination, a prior infection or both, Samet said. A recent study estimated surviving a previous COVID-19 infection reduces the odds that reinfection will lead to hospitalizations by about 90% for 40 weeks. Protection from milder infection faded faster, however, particularly if a person had been infected with one of the omicron subvariants.

Data from the state health department and the CDC showed:

• 10.9% of tests came back positive over the last seven days, up marginally from 10.5% the previous week
• 3,090 new cases were reported in the week ending Sunday, down from 3,280 the previous week
• Viral concentrations were rising in 32 utilities’ wastewater, falling in 21 and stable in 13. Last week, they were rising in 24, falling in 13 and stable in 29.
• Three Colorado counties were at high risk, based on cases and hospitalizations: Alamosa, Rio Grande and Saguache. Seven others were at medium risk. Last week, four counties were at medium risk and none were at high risk.
• 45 counties had “substantial” or “high” transmission, based on cases and the positivity rate. Last week, 36 did.

The state health department reported 17 hospitalizations for respiratory syncytial virus in the week ending Saturday, down from 23 in the previous week.