Coronavirus cases and hospitalizations have increased statewide, mirroring a rise in transmission that is taking place across the United States as immunity wanes and new variants circulate, according to public health officials.
COVID-19 cases in Colorado have gradually increased since June, but now the uptick in transmission is coming as children are heading back to school and as the cold and flu season is approaching, both of which could further spread the virus, they said.
Still, both cases and hospitalizations remain at some of the lowest levels since the pandemic began three years ago.
“Unfortunately, there’s just a lot of COVID out there so we do expect the number of hospitalizations to go up,” said state epidemiologist Dr. Rachel Herlihy.
Last week, 99 Coloradans were hospitalized with the virus – 22 more than the 77 people hospitalized the previous week, according to data from the Colorado Department of Public Health and Environment.
Despite last week’s jump, COVID-19 hospitalizations remain very low compared to previous years. Hospitalizations surpassed 1,800 and 1,600 during two of the worst waves of the pandemic in 2020 and 2022, respectively, according to the data.
By comparison, hospitalizations hit their lowest point earlier this month, with only 56 people being treated for COVID-19, according to the data.
Hospitalization data is one of the best indicators of what is happening with COVID-19, Herlihy said.
It’s difficult to understand how much the virus is spreading compared to previous years because more people are not testing or if they are, they are doing so at home, and are less likely to report their results to the health department, she said.
This has made COVID-19 data a bit murky, but the state health department has also seen test positivity rates increasing, indicating that the rise in cases is not just due to more people testing but due to wider transmission of the virus, Herlihy said.
Summer bump in cases
Colorado has previously experienced small COVID-19 upticks in the late summer and early fall, with cases dropping ahead of a larger increase in cases in the winter, Herlihy said.
It’s unclear why transmission of the virus has increased in the summer, said Beth Carlton, an associate professor of environmental and occupational health at the Colorado School of Public Health.
“We don’t fully understand why that is,” she said. “We also don’t know if those summer waves are slowly going to go away.”
One theory on why cases increase in the summer is because of waning immunity. Another theory is that people are heading inside to avoid the heat, leading to indoor crowding, Carlton said.
Public health officials attributed the current increase in transmission to waning immunity and new variants of the virus.
One of the new strains circulating is called EG.5, or Eris, and is similar to previous versions of the virus. But there are changes in the variant that is likely leading it to infect people who have previously had COVID-19 or are vaccinated, Herlihy said.
Colorado added almost 1,000 new COVID-19 cases last week, with the state reporting 1,746 new cases on Wednesday. Wastewater data also showed transmission was steadily increasing in 16 communities, including in the Denver metro, Castle Rock, Loveland, and Telluride, according to the health department.
Denver is seeing about 33 or 34 COVID-19 cases per 100,000 people right now, which is up slightly, but well below the more than 2,200 cases per 100,000 people the city saw last year, said Bob McDonald, executive director of the city’s Department of Public Health & Environment.
“It’s a fraction of what comes close to becoming a concern,” he said, adding, “It’s just that time of year we all need to recognize respiratory season is coming. These viruses do well in the winter months.”
Many COVID-19 symptoms remain the same, including fever, cough, body aches, runny noses, and congestion, according to medical experts.
For most people, getting COVID-19 will feel like a bad cold or the flu. But people with chronic illnesses, cancer and autoimmune diseases are still at a higher risk of developing more severe symptoms, said Dr. Carrie Horn, chief medical officer of National Jewish Health.
“We are seeing an increase in hospitalizations, but not a huge increase and nothing like the beginning of the pandemic,” she said. “It’s still – for most people – something you can deal with at home.”
There are multiple reasons people are having milder symptoms, including the availability of COVID-19 vaccines, they may have built up some immunity and different variants of the virus are circulating, Horn said.
People who have mild cases still have an elevated risk of developing long COVID, which occurs when symptoms persist or develop after their initial infection. These symptoms include lung problems, fatigue, and diabetes, according to a new study published in Nature Medicine.
What to do if you have COVID-19
Medical and public health experts also offered familiar advice to Coloradans who have COVID-19 symptoms: Stay home when you are sick and get vaccinated/boosted.
A new vaccine targeting some of the new variants is likely to be available in late September or early October for people looking to get another booster shot, Herlihy said.
There are also treatments, such as Paxlovid, available for people who have COVID-19 and are at a higher risk for severe symptoms, she said.
A person with COVID-19 should try to minimize transmission of the virus by staying home, Horn added.
“The bigger effect is people not going out when they are sick,” she said. “Staying home from school, staying home from work, if they can afford to – it really helps prevent everyone else from getting sick.”
If a person is not sick, then they should make sure to wash their hands. Masking is also still a good idea to prevent their exposure to the virus, especially when in crowded indoor spaces, Horn said.
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