Bordetella pertussis is the bacteria that causes whooping cough, also known as pertussis. When a youngster coughs hard, their breathing may produce a "whooping" sound. For some people, whooping cough might result in serious illness. The most vulnerable to acquiring a major illness from the illness are infants under one year old and people with immune system or respiratory conditions. Here are the symptoms and causes of whooping cough at IMC Hospital.