title: Molecular typing of Bordetella pertussis isolates recovered from Belgian children and their household members.
abstract: Recently, a moderate increase in the prevalence of pertussis, possibly contracted from adults, has been observed among unvaccinated children. During a 3-year period, we prospectively enrolled 93 index patients with a polymerase chain reaction (PCR) and/or culture result positive for Bordetella pertussis. Among 63 household contacts of 28 index patients, PCR and culture for B. pertussis identified 25 B. pertussis-positive persons. Nineteen of 25 B. pertussis-positive household contacts were asymptomatic. Isolates were available from 10 families of both index patients and household contacts for molecular typing by pulsed-field gel electrophoresis (PFGE) and for genotyping of pertactin and pertussis toxin by sequence-specific PCR and sequencing. PFGE demonstrated homogeneity among the isolates recovered from within each family but heterogeneity among the isolates recovered from different families. B. pertussis isolates recovered from index patients and their household contacts were indistinguishable by molecular typing, demonstrating that identical strains can cause full pertussis disease in children and asymptomatic infection in adults and adolescents.
authors.affiliation: Department of Pediatrics, Pediatric Respiratory Medicine and Cystic Fibrosis Clinic, Academisch Ziekenhuis-Vrije Universiteit Brussel, Brussels, Belgium.
authors.forename: Iris
authors.initials: I
authors.lastname: De Schutter
authors.forename: Anne
authors.initials: A
authors.lastname: Malfroot
authors.forename: Isidoor
authors.initials: I
authors.lastname: Dab
authors.forename: Nathalie
authors.initials: N
authors.lastname: Hoebrekx
authors.forename: Gaëtan
authors.initials: G
authors.lastname: Muyldermans
authors.forename: Denis
authors.initials: D
authors.lastname: Piérard
authors.forename: Sabine
authors.initials: S
authors.lastname: Lauwers
mesh_terms: D000293:Adolescent; D000328:Adult; D015373:Bacterial Typing Techniques; D001530:Belgium; D001886:Bordetella pertussis / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D002648:Child; D016521:Electrophoresis, Gel, Pulsed-Field; D005190:Family; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D014917:Whooping Cough / Q000382:microbiology*