Whooping cough wave now worst in almost a decade amid back-to-school surge CBS NewsNebraskans encouraged to get the Pertussis vaccine after an increase in whooping cough KOLNMayo Clinic Minute: What is whooping cough? Mayo ClinicDHS: Wisconsin whooping cough cases increasing ‘significantly’ FOX 6 MilwaukeeState reporting ‘significant increase’ in whooping cough cases WISN Milwaukee