RT Journal Article
SR Electronic
T1 Predictors of clustering of tuberculosis in Greater Vancouver: a molecular epidemiologic study
JF Canadian Medical Association Journal
JO CMAJ
FD Canadian Medical Association
SP 349
OP 352
VO 167
IS 4
A1 Eduardo Hernández-Garduño
A1 Dennis Kunimoto
A1 Lei Wang
A1 Mabel Rodrigues
A1 R. Kevin Elwood
A1 William Black
A1 Sunny Mak
A1 J. Mark FitzGerald
YR 2002
UL http://www.cmaj.ca/content/167/4/349.abstract
AB Background: The understanding of how tuberculosis is transmitted can be improved by combining DNA fingerprinting of Mycobacterium tuberculosis with conventional epidemiologic methods. We used such techniques to determine the predictors of clustering of identical isolates from tuberculosis patients in Vancouver. Methods: We used the restriction fragment length polymorphism (RFLP) technique and, if necessary, spoligotyping to determine DNA patterns of M. tuberculosis isolates from all patients with newly diagnosed tuberculosis in Greater Vancouver reported to the Division of Tuberculosis Control from January 1995 to March 1999. Isolates were considered to be part of a cluster if they had an identical DNA pattern. We also collected demographic and epidemiologic data. Predictors associated with being in a cluster were analyzed in a multivariate logistic regression model. Results: Isolates from 793 patients (430 men) were identified; 137 (17.3%) were considered to be in clusters. After adjustment for multiple potential predictors, we found that the following patients were more likely to be part of a cluster: Canadian-born Aboriginals (v. foreign-born patients) (adjusted odds ratio [OR] 6.0, 95% confidence interval [CI] 3.0–11.7), Canadian-born non-Aboriginals (v. foreign-born patients) (adjusted OR 3.6, 95% CI 2.1–6.3), and injection drug users (v. patients who did not inject drugs) (adjusted OR 3.9, 95% CI 1.9–8.1). Patients with a prior history of tuberculosis were less likely to be part of a cluster than were patients with no history of tuberculosis (adjusted OR 0.3, 95% CI 0.1–0.8). Interpretation: Our findings indicate the need to target groups at high risk of tuberculosis more aggressively to prevent transmission and to treat latent infection. DNA fingerprinting may be a useful adjunct to conventional epidemiologic methods to monitor the transmission of tuberculosis in an innter-city setting.