Pertusis affects which age –
In prevaccine era, and in countries where immunization is limited the peak incidence of pertussis is in children 1-5 years of age, infant accounts for < 15% of cases.
In recent years, where vaccination is employed, approximately one half of cases have occurred in infants younger than 1 year of age and one fourth in adolescent and adults.
2–3
<5
5–7
> 10 years