title: Examining DNA fingerprinting as an epidemiology tool in the tuberculosis program in the Northwest Territories, Canada.
abstract: BACKGROUND
  Tuberculosis (TB) is an important public health problem in the Northwest Territories (NWT), particularly among Canadian Aboriginal people.
  
  
  OBJECTIVE
  To analyse the transmission patterns of tuberculosis among the population living in the NWT, a territorial jurisdiction located within Northern Canada.
  
  
  METHODS
  This population-based retrospective study examined the DNA fingerprints of all laboratory confirmed cases of TB in the NWT, Canada, between 1990 and 2009. An isolate of each lab-confirmed case had genotyping done using IS6110 Restriction Fragment Length Polymorphism. DNA patterns were assigned to each DNA fingerprint, and indistinguishable fingerprints patterns were assigned a cluster. Social network analysis (SNA) was used to examine direct linkages among cases determined through conventional contact tracing (CCT), their DNA fingerprint and home community.
  
  
  RESULTS
  Of the 225 lab-confirmed cases identified, the study was limited to 195 subjects due to DNA fingerprinting data availability. The mean age of the cases was 43.8 years (±22.6) and 120 (61.5%) males. The Dene (First Nations) encompassed 120 of the cases (87.7%), 8 cases (4.1%) were Inuit, 2 cases (1.0%) were Metis, 7 cases (3.6%) were Immigrants and 1 case had unknown ethnicity. One hundred and eighty six (95.4%) subjects were clustered, resulting in 8 clusters. Trend analysis showed significant relationships between with risk factors for unemployment (p=0.020), geographic location (p≤0.001) and homelessness (p≤0.001). Other significant risk factors included excessive alcohol consumption, prior infection with Mycobacterium tuberculosis and prior contact with a case of TB.
  
  
  CONCLUSIONS
  This study demonstrates how DNA fingerprinting and SNA can be additional epidemiological tools, along with CCT method, to determine transmission patterns of TB.
authors.affiliation: Health Sciences, University of Alaska, Anchorage, AK, USA. cheryl_case@gov.nt.ca
authors.forename: Cheryl
authors.initials: C
authors.lastname: Case
authors.forename: Kami
authors.initials: K
authors.lastname: Kandola
authors.forename: Linda
authors.initials: L
authors.lastname: Chui
authors.forename: Vincent
authors.initials: V
authors.lastname: Li
authors.forename: Nancy
authors.initials: N
authors.lastname: Nix
authors.forename: Rhonda
authors.initials: R
authors.lastname: Johnson
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D001110:Arctic Regions / Q000453:epidemiology; D016172:DNA Fingerprinting; D004269:DNA, Bacterial; D005260:Female; D015438:Health Behavior; D006703:Ill-Housed Persons; D006801:Humans; D004930:Inuit; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000235:genetics*; D015873:Northwest Territories / Q000453:epidemiology; D012150:Polymorphism, Restriction Fragment Length; D012189:Retrospective Studies; D012307:Risk Factors; D017678:Sex Distribution; D012959:Socioeconomic Factors; D014376:Tuberculosis / Q000208:ethnology* / Q000235:genetics* / Q000635:transmission; D055815:Young Adult
chemical_list: D004269:DNA, Bacterial
keywords: DNA fingerprinting; RFLP; aboriginal; contact tracing; social network analysis; tuberculosis transmission