Bordetella pertussis infection in adolescents

AIMS. Over the last decade several changes occurred in the field of pretussis. B. pertussis infection and illnesses are common and endemic in adults and these infections are the reservoir for pertussis in susceptible children and infants. METHODS. In a case-control study, 50 patients more than 18 years old with paroxysmal cough lasting more than 2 weeks were compared with 50 controls without history of cough. Nasopharyngeal swab culture and IgG antibody titers to Boredetella pertussis antigens by ELASA methods were used. RESULTS. Anti-pertussis antibody was 12% positive, in control and 48% positive, in cases and this difference was statistically significant (P value < 0.001). Also the increase of mean antibody titer between acute and convalescent serum in cases after two weeks was statistically significant (P value=0.04). Patient’s culture was positive in 2% in cases and was not isolated from any of controls. CONCLUSION. Immunity after immunization and even infection is not life long. The frequent finding of asymptomatic antibody boosting in an immune person proves susceptibility for infection and probably active transmission despite protection from disease and supports of this hypothesis until pertussis in adults is universally prevented through immunization, clinicians must be on the alert of the clinical disease.