Pertussis
Pertussis (whooping cough) is a highly contagious disease involving the respiratory tract. It is caused by a bacterium that is found in the mouth, nose, and throat of an infected person. Approximately 5000 to 7000 cases are typically reported annually in the U.S. It is named after the "whoop" sound some children and adults make when they try to breathe in during or after a severe coughing spell.