The epidemiology of pertussis: a comparison of the epidemiology of the disease pertussis with the epidemiology of Bordetella pertussis infection.

In the prevaccine era pertussis epidemics followed a cyclic pattern, with peaks every 2 to 5 years. With the marked reduction of pertussis by vaccination, the same cyclic pattern still occurs. Studies relating to reported pertussis and Bordetella pertussis infection have been reviewed and analyzed. The increase in reported pertussis over the last 2 decades is mainly due to a greater awareness of pertussis and perhaps to the use of several less efficacious vaccines. Studies of prolonged cough illnesses in adolescents and adults reveal that 13% to 20% are a result of B pertussis infection. Serologic studies suggest that the rate of B pertussis infection in adolescents and adults is approximately 2.0% per year. The rate of cough illnesses (pertussis) caused by B pertussis infection in adolescents and adults is between 370 and 1500 per 100,000 population. These data suggest that there are between approximately 800,000 and 3.3 million cases per year in the United States. The coming availability of adolescent- and adult-formulated diphtheria and tetanus toxoids and acellular pertussis vaccines for adolescents and adults and their widespread use should reduce the reservoir of B pertussis disease. It is suggested that a universal program of adolescent and adult boosters would decrease the circulation of B pertussis in these age groups and possibly could lead to the elimination of the organism from the population.