The United States is seeing a second peak in flu cases this season. After doctor’s office visits for flu dipped early this year, they jumped past the previous season peak at the end of last month, with a 30% test positivity rate — and there are still months to go.

The U.S. winter virus season is in full force, and by one measure is the most intense in 15 years. One indicator of flu activity is the percentage of doctor’s office visits driven by flu-like symptoms.

The Centers for Disease Control and Prevention lists Illinois in the high category for flu cases, and across the Chicago area, emergency department visits, hospital admissions, and ICU admissions for the flu are currently higher than the peak of last season.

The U.S. is experiencing its most intense flu season in 15 years, with 24 million infections, 310,000 hospitalisations, and 13,000 deaths, according to the Centers for Disease Control and Prevention.