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 (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 Minnesota Department of Health released updated numbers Thursday, showing the state has reached 1,019 cases of whooping cough for the year.

A nationwide whooping cough surge has infected nearly 2,200 Pennsylvanians, outpacing every other state and putting local medical experts on high alert. The national Centers for Disease Control and Prevention have identified more than 16,

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.