Influenza is hitting Routt County earlier this year than last flu season, according to Routt County Public Health, and the number of positive flu cases is 71% higher now than the same time last year, according to UCHealth Yampa Valley Medical Cetner.
“We are a couple of weeks earlier than last year in detecting it in the wastewater,” Routt County Public Health Director Roberta Smith said Wednesday.
This fall/winter season, influenza A was first reported via Steamboat Springs Wastewater Plant monitoring on Nov. 19 and has been consistently detected since then with a spike on Dec. 15, Smith said.
“Every day for the last week, I have thought this is exponential growth,” Lauren Bryan, infection prevention program manager at UCHealth YVMC, said of flu cases. “The epidemiologic curve is not curved. It looks like an arrow going upward.”
“Flu is particularly severe for the very young, people 65 or older, pregnant women and people with chronic illnesses,” Bryan noted. “Flu is contagious for one day prior to symptoms and seven days after symptom onset. Flu can live on hard, dry surfaces for 24-48 hours.”
In early 2025, the high spike of influenza found during monitoring at the wastewater plant occurred on Jan. 15, so Smith said that is another warning sign that should encourage residents to come into a medical clinic or the Public Health Office soon for a flu shot. The public health office at Oak and Sixth streets in downtown Steamboat offers free flu shots for people who are uninsured or if their health insurance does not cover flu shots.
“While the vaccine is not a perfect match, the evidence does show that it has reduced flu severity, reducing ER visits for flu by 72-75% in children and by 32-39% in adults,” Bryan said.
Bryan said 90% of flu cases in the past two weeks have been influenza A, which “tends to be more severe.” She noted a person requires two weeks for their body to develop antibodies after getting the flu vaccine and that only 28% of Routt residents received a flu vaccine in 2025.
“Stay home if you are not feeling well,” Bryan advised. “Avoid people who are coughing, snotting/snorting. Wash your hands. Disinfect common surfaces — think the grocery cart handle.”
“This is a particularly bad time of the year for flu to be hitting as people are gathering for Christmas/New Year’s, and that always increases the spread with the compounding factor of an immune-evading viral mutation,” Bryan noted.
Cases of flu are spiking statewide, according to Colorado public health officials.
“If you look at the numbers from past years, there’s been an acceleration in cases statewide, and we are starting off with a bang statewide,” Smith said. “We are seeing an increase in hospitalizations statewide.”
UCHealth YVMC Communications Manager Lindsey Reznicek said the hospital has documented positive cases of flu in people from age 9 months to 90 years and has seen “related hospitalizations of Routt County residents, other Coloradoans and individuals from out of state.”
Reznicek said UCHealth Urgent Care on Mid Valley Drive experienced its busiest day on record with 82 patients on Dec. 26, after the clinic was closed for its only “down day” of the year on Christmas Day. Top symptoms from patients on the day after the holiday were cough, sore throat and fever, including some positive flu tests.
Positive flu tests processed through the hospital lab have shown that 42% of individuals with the flu are from Colorado, with 78% of those from Routt County. Of the 58% of flu victims from outside Colorado, top states, in descending order, were Texas, New York, Illinois, Florida, Tennessee, Mississippi and Ohio, Reznicek said.
The Colorado Department of Public Health and Environment’s Viral Respiratory Diseases Data webpage shows one pediatric patient death from influenza so far since Oct. 1 this flu season.
Flu patients usually begin to feel symptoms two days after exposure, but symptom onset can range from one to four days, according to the CDPHE. Flu victims often may experience fever, cough, sore throat, runny or stuffy nose, muscle or body aches, headaches or fatigue. Some patients may experience vomiting and diarrhea, though this is more common in children, according to the CDPHE.
Smith said she cannot predict the severity of the flu season in Routt County this winter with “so many different variables from year to year,” adding that “tourism is probably the biggest fluctuation.”
Sheli Steele, marketing and communications director at Memorial Regional Health in Craig, said year-over-year data comparing 2024 to 2025 showed positive flu cases tested through MRH increased by 9%. Two flu patients were admitted to the Craig hospital this month.
The Steamboat wastewater plant staff monitors for the presence of six viruses found in sewage that comes from residents, commuting employees, visitors and travelers.
