Iowa has seen an increase in cases of Pertussis or Whooping Cough.  Infection Control and Employee Health Nurse Lorraine Hardt at the Washington County Hospital and Clinics says the most common symptom is a persistent and violent cough.   She says the cough usually gets worse at night and lasts approximately three weeks.  Hardt shares that children around the age of ten catch whopping cough the easiest because their immunity from vaccinations has declined.  She continues to say if you think you have whooping cough, you should see your doctor right away as you are contagious until you have completed five days of antibiotics or after three weeks.  For more information, contact your doctor or Washington County Public Health.