title: Culture-positive Pediatric Tuberculosis in Toronto, Ontario: Sources of Infection and Relationship of Birthplace and Mycobacterial Lineage to Phenotype.
abstract: BACKGROUND
  Few data relate Mycobacterium tuberculosis (Mtb) lineage and disease phenotype in the pediatric population or examine the contribution of travel to the tuberculosis (TB)-endemic country in North America. We examined clinical, demographic and Mtb genotype data from patients with TB who were treated in Toronto between 2002 and 2012.
  
  
  METHODS
  Consecutive Mtb culture-positive, pediatric patients were included. Clinical data were collected from a prospectively populated clinical database. Mtb case isolate genotypes were identified using Mycobacterial Interspersed Repetitive Units-Variable Number Tandem Repeat (MIRU-VNTR) and spoligotyping and were categorized into phylogeographic lineages for analysis.
  
  
  RESULTS
  The 77 patients included 30.4% of all culture-positive pediatric TB cases in Ontario from 2002 to 2012. Seventy-six (99%) patients were first or second generation Canadians. Foreign-born patients were more likely to have extrathoracic disease [odds ratios (OR) = 3.0; 95% confidence interval (CI): 1.04-8.71; P < 0.05] and less likely to have a genotype match in the Public Health Ontario Laboratories database [OR = 0.32 (95% CI: 0.11-0.90); P < 0.05] than Canadian-born patients. For those without a known TB contact, Canadian-born patients were more likely to have travelled to a TB-endemic country [OR = 13.0 (95% CI: 2.5-78.5); P < 0.001]. Extrathoracic disease was less likely in patients infected with the East Asian Mtb lineage [OR = 0.1 (95% CI: 0.01-0.9); P < 0.05] and more likely in those infected with the Indo-Oceanic Mtb lineage [OR = 5.4 (95% CI: 1.5-19.2); P < 0.05].
  
  
  CONCLUSIONS
  Travel to TB-endemic countries likely plays an important part in the etiology of pediatric TB infection and disease, especially in Canadian-born children. Mtb lineage seems to contribute to disease phenotype in children as it has been described in adults.
authors.affiliation: From the Divisions of *Respiratory Medicine and †Infectious Diseases, The Hospital For Sick Children; ‡Public Health Ontario Laboratories, Public Health Ontario; and Departments of §Laboratory Medicine and Pathobiology and ¶Pediatrics, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Jonathan H
authors.initials: JH
authors.lastname: Rayment
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Guthrie
authors.forename: Karen
authors.initials: K
authors.lastname: Lam
authors.forename: Michael
authors.initials: M
authors.lastname: Whelan
authors.forename: Brenda
authors.initials: B
authors.lastname: Lee
authors.forename: Frances B
authors.initials: FB
authors.lastname: Jamieson
authors.forename: Ian
authors.initials: I
authors.lastname: Kitai
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000995:Antitubercular Agents / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005838:Genotype; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000145:classification / Q000187:drug effects / Q000235:genetics; D016017:Odds Ratio; D009864:Ontario / Q000453:epidemiology; D062486:Public Health Surveillance; D012189:Retrospective Studies; D012307:Risk Factors; D014376:Tuberculosis / Q000453:epidemiology* / Q000382:microbiology
chemical_list: D000995:Antitubercular Agents