Hospitals are seeing an increase in patients suffering from respiratory illnesses, including the flu, COVID-19, and the Respiratory Syncytial Virus, or RSV, according to city, county, and state officials.

Those infections come amid holiday gatherings and travel. Health experts in the Chicago area said the illnesses are trending in the wrong direction.

COVID-19 and RSV are relatively low in Chicago and Cook County, but it's the flu that's prompting health officials to sound the alarm.

"It's spreading widely right now, with steep growth curves in many places," said Dr. Kiran Joshi.

Dr. Joshi is the chief operating officer at the Cook County Department of Public Health, and said flu activity in the county jumped to a high level, especially with patients from one age group.

"We're already seeing more hospitalizations and emergency room visits, particularly among children," He said.

Dr. Joshi said that's likely to spread to adults and older people as the season continues.

According to CDPH, tests that were positive for influenza increased from about 9% to about 17% just this past week.

At Rush University Hospital, they are in the midst of an upswing. Doctor Michael Lin explained what may be leading to this season's spike.

"This year's flu strain that is dominated by subclade K, so it's a strain that has mutated to make itself more contagious. It's not a perfect match to the vaccine, but the vaccine is still expected to be effective in preventing hospitalizations and serious illness," he said.

Doctors said it's not too late to get the flu shot, which is still the best tool to reduce the risk of needing to go to the hospital.

"This year, because we're seeing an outsize number of flu cases, the flu vaccine is especially important," Dr. Lin said. 

In addition to getting the flu shot, every day things like washing your hands, cleaning frequently touched surfaces, wearing masks, especially when sick, and avoiding crowds if sick can help reduce the spread this season as winter gatherings continue.

"If you're really sick, stay home, don't go to that New Year's Eve party, stay home until you're feeling better and fever-free," Dr. Joshi said.

Residents in Cook County and Chicago search for the clinics near them that offer free flu and COVID shots.