Pertussis is a very contagious disease caused by the bordetella pertussis bacteria which is transmitted from person to person. Pertussis affects the lungs and airwaves of the infected person. Pertussis is also called whooping cough because of the sound of the serve cough it causes. Pertussis also interferes with breathing. Pertusssis can last several weeks and can lead to pneumonia, seizures, brain damage, and even death.