Epidemiological, clinical, and laboratory aspects of pertussis in adults

In populations without immunization, pertussis is a high-incidence, endemic disease with cyclic epidemic peaks occurring every 2-5 years. The universa l use of pertussis vaccines in children results in a marked reduction in in cidence, but the frequency of disease cycles does not lengthen. This indica tes that the organism (Bordetella pertussis) remains prevalent in the popul ation. Studies of prolonged cough illnesses in adolescents and adults indic ate that between 12% and 32% are the result of B. pertussis infection. Sero logical survey data indicate that all adults have been previously infected, and IgA antibody studies suggest that infections in adults are as frequent in the United States, where pertussis has been controlled, as in Germany, where pertussis has been epidemic. Because of the apparent reservoir of B. pertussis infections in adolescents and adults, I believe that B. pertussis circulation cannot be controlled by our present childhood immunization pro gram. Acellular pertussis vaccines make adolescent and adult booster immuni zation programs possible, and these could lead to a decrease in the circula tion of the organism.