Eight cases of pertussis have been confirmed in the Wallingford-Swarthmore School District since the beginning of the school year, according to Superintendent Lisa Palmer. The diagnosed students have been from Swarthmore-Rutledge School, Strath Haven Middle School, and Strath Haven High School. The highly contagious disease, which affects the lungs, is commonly known as whooping cough because of the sound sufferers sometimes make after a long fit of coughing.