Prognosis of Pertussis Pertussis, commonly known as whooping cough, commonly occurs in infants. It is a serious respiratory condition which leads to hospitalization and development of respiratory distress. 50% of paediatric patients have apnea, 20% have pneumonia, 1% has seizures, and 0.3% have encephalopathy. The fatality rate is only 1%. The prognosis of pertussis requires time and attention to every symptom. Patients usually recover completely within few weeks. However, malaise and paroxysms of coughing persist for several weeks.