Even though flu season started later than usual in Maricopa County, the number of cases has increased dramatically compared to a year ago.

More than 17,000 people have been infected with the flu this season in the county. This is a 42% increase from this time last year and more than 100% higher than the average over the past five years.

Travel and virus mutations are the main drivers of spread.

Jared Berkowitz, a doctor at Honor Health Clinic, is now asking patients and staff to wear masks during appointments.

“It’s really about taking care of yourself and your fellow citizens around you. We’re just doing our best to prevent the spread, and nothing is perfect,” Berkowitz said.

Samia Qadri, a Banner Health emergency care specialist, said this year’s outbreak is stronger than in previous years and fewer people have been vaccinated.

“We’ve noticed that people are thinking, ‘I didn’t get vaccinated this year,’ and we’re seeing more severe symptoms in those patients,” Kadri said.

Kadri said his team is always preparing for the busy flu season and is encouraging people to get vaccinated this season as well. After several days of strong winds, Qadri believes there could be more cases of influenza in the coming days.

“It takes two to three weeks for the immune system to respond and build antibodies,” Kadri said. “From now on, we recommend that you get vaccinated in early October.”

Officials expect the remainder of the season, which typically runs through the end of February, to be busy. Berkowitz urges people to get their flu shots, wash their hands frequently and isolate if they’re sick.