Local cases of whooping cough have quadrupled since May, the Snohomish County Health Department reported this week. So far this year, the county has seen at least 41 cases of pertussis, the highly contagious respiratory illness known as whooping cough,

Health officials in Snohomish County are sounding the alarm over a spike in whooping cough cases, a highly contagious respiratory infection also known as pertussis.

Whooping cough is on the rise in Snohomish County, with the health department confirming more than 40 cases of pertussis so far this year.