Whooping cough (pertussis) infections continue to rise in the U.S., with the Centers for Disease Control and Prevention estimating more than 17,600 cases as of Oct. 5.

The CDC had documented more than 17,600 infections as of Oct. 5—more than four times those recorded at this time last year.

Whooping cough is spreading nationwide at the highest levels since 2014. There have been about 17,500 cases this year — more than four times as many compared to the same time last year — and four confirmed deaths.