title: Epidemiological features of pertussis in hospitalized patients in Canada, 1991-1997: report of the Immunization Monitoring Program--Active (IMPACT).
abstract: To assess the morbidity associated with the continued high levels of pertussis, we studied all children <2 years of age who were admitted to the 11 Immunization Monitoring Program--Active (IMPACT) centers, which constitute 85% of Canada's tertiary care pediatric beds. In the 7 years preceding implementation of acellular pertussis vaccine, a total of 1,082 pertussis cases were reported, of which 49.1% were culture-confirmed. The median age of the patients was 12.4 weeks; 78.9% of cases were in children <6 months of age. Complications of pertussis were common: pneumonia was reported in 9.4% of cases, new seizures in 2.3%, and encephalopathy in 0.5%. There were 10 deaths (0.9%), all in children < or =6 months of age. Duration of hospitalization was longer (9.3 days vs. 4.9 days; P = .001) and intensive care was required more frequently (19.2% vs. 4.9%; P = .001) in infants under <6 months of age than in those > or =6 months. Pertussis continues to cause significant morbidity and occasional mortality in Canada, particularly in young infants.
authors.affiliation: Department of Pediatrics, Dalhousie University, IWK Grace Health Centre, Halifax, Nova Scotia, Canada. shalperin@iwkgrace.ns.ca
authors.forename: S A
authors.initials: SA
authors.lastname: Halperin
authors.forename: E E
authors.initials: EE
authors.lastname: Wang
authors.forename: B
authors.initials: B
authors.lastname: Law
authors.forename: E
authors.initials: E
authors.lastname: Mills
authors.forename: R
authors.initials: R
authors.lastname: Morris
authors.forename: P
authors.initials: P
authors.lastname: Déry
authors.forename: M
authors.initials: M
authors.lastname: Lebel
authors.forename: N
authors.initials: N
authors.lastname: MacDonald
authors.forename: T
authors.initials: T
authors.lastname: Jadavji
authors.forename: W
authors.initials: W
authors.lastname: Vaudry
authors.forename: D
authors.initials: D
authors.lastname: Scheifele
authors.forename: G
authors.initials: G
authors.lastname: Delage
authors.forename: P
authors.initials: P
authors.lastname: Duclos
mesh_terms: D002170:Canada / Q000453:epidemiology; D005260:Female; D006760:Hospitalization; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010567:Pertussis Vaccine / Q000276:immunology*; D013997:Time Factors; D014611:Vaccination; D014917:Whooping Cough / Q000453:epidemiology*
chemical_list: D010567:Pertussis Vaccine