February 1994

Outbreak of Pertussis in a Fully Immunized Adolescent and Adult Population

Author Affiliations

From the St Louis (Mo) University School of Medicine, Center for Vaccine Development.

Arch Pediatr Adolesc Med. 1994;148(2):153-157. doi:10.1001/archpedi.1994.02170020039006

Objective:  To evaluate the spread of pertussis in a fully immunized eighth-grade class and the household contacts of two coindex cases of pertussis.

Design:  Survey of infected subjects and their contacts was performed using culture, direct fluorescent antibody assay, and serological assays to establish the diagnosis of Bordetella pertussis.

Setting:  Middle-class parochial school.

Participants:  A volunteer sample of 15 eighth-grade students and 13 household contacts of two identified cases of B pertussis infection.

Interventions:  All participants had medical histories (including immunization status) and laboratory evaluation for B pertussis infection (including nasopharyngeal specimens and serum samples) obtained initially and 30 days later. After initial evaluation, all subjects received erythromycin ethyl succinate therapy.

Main Outcome Measures:  Assessment of B pertussis infection as defined by positive nasopharyngeal culture, direct fluorescent antibody, or serological tests.

Results:  Laboratory evidence of B pertussis infection was found in eight (47%) of 17 immunized eighth-grade classmates and in three (23%) of 13 household contacts, all of whom were 12 years of age or older.

Conclusions:  Vaccine-induced immunity wanes by early adolescence. These older age groups may be infected with B pertussis and may serve as reservoirs of infection for other susceptible individuals.(Arch Pediatr Adolesc Med. 1994;148:153-157)