Pertussis epidemiology and demographics

Overview
This disease results in high morbidity and mortality in many countries every year. In the United States, 5000-7000 cases are reported each year. Incidence of pertussis has increased steadily since the 1980s. The incidence in 2002 was 3.01/100,000 when 8,296 cases of pertussis were reported.

Trends in Pertussis Disease in the United States
In the United States, the highest recorded annual incidence of pertussis occurred in 1934 when greater than 260,000 cases were reported. The incidence of reported pertussis disease declined substantially as use of whole-cell DTP vaccines became widespread. By 1970, the reported incidence had declined greater than 99%; the fewest cases (1,010) were reported in 1976. However, since the early 1980s reported pertussis incidence has increased steadily. Cyclical peaks in incidence occurred in 1983, 1986, 1990, and in 1993 when 6,586 cases were reported -- more than in any year since 1976. The number of reported cases has increased in all age groups, but the increase is greatest among persons aged greater than or equal to 5 years. Nevertheless, infants and young children continue to have the highest risk for pertussis and its complications.