Incubation period of pertussis is –

Pertussis After an incubation period of about 1-2 weeks, the disease takes a protracted course comprising three stages, - the catarrhal, paroxysmal and Convalescent - each lasting approximately two weeks. B. pertussis infection               ↓ Incubation period (1-2 weeks)              ↓ Catarrhal stage (1-2 weeks)              ↓ Paroxysmal stage (2-4 weeks)             ↓ Convalescent stage (1-2 weeks but may last 1 to 3 months) Remember Catarrhal stage is the stage of maximum infectivity. Maximum complications occur in Paroxysmal stage.