Whooping cough, or pertussis, is very contagious and mainly affects infants and young children. Whooping cough is caused by a bacterium called B ordetella pertussis. The illness is characterized by coughing spells that end with a characteristic "whoop" as air is inhaled. Feb 23, · Whooping cough is an infection that is more common in children, but adults can also contract it. The symptoms are usually less severe in adults than in children. This article discusses the.