Whooping cough cases in Colorado have tripled so far this year, and schools are experiencing clusters of the preventable respiratory disease, according to the state health department.
The Centers for Disease Control and Prevention reported Colorado had 333 cases of pertussis, the formal name for whooping cough, as of Aug. 3. At the same time last year, the state had 90 cases.
Nationwide, cases so far this year have more than tripled compared to last year, with the highest counts in Pennsylvania and New York.