Five times as many cases of the potentially fatal illness have been reported so far in 2024, compared with the same time last year.

Whooping cough is at its highest level in a decade for this time of year, U.S. health officials reported Thursday. There have been 18,506 cases of whooping cough reported so far, the Centers for Disease Control and Prevention said.

Whooping cough usually peaks every three to five years, and the latest numbers indicate a return to levels before the pandemic.