In which stage of the illness does the whooping cough associated with pertussis occur?

The paroxysmal stage is characterized by intense and severe coughing fits, which are a hallmark of whooping cough caused by Bordetella pertussis. During this phase, individuals experience sudden, uncontrollable episodes of coughing, which can be followed by a "whoop" sound as they struggle to breathe in. These coughing paroxysms can be distressing and may occur in rapid succession, leading to exhaustion and potential complications.

In contrast, the initial stage involves mild respiratory symptoms, resembling those of a common cold. The catarrhal stage precedes the paroxysmal phase and is marked by symptoms such as runny nose, sneezing, and mild cough, but without the characteristic severe coughing fits. Lastly, the convalescence stage follows the paroxysmal stage, during which the coughing gradually decreases and recovery begins. Understanding the progression of pertussis symptoms helps in timely diagnosis and management of the illness.