Drug resistance study of Mycobacterium tuberculosis in Canada, February 1, 1993 to January 31, 1994.
OBJECTIVE
To estimate the prevalence of resistance of Mycobacterium tuberculosis to first-line antituberculosis drugs in Canada.


METHODS
M. tuberculosis isolates from one third of all culture-positive tuberculosis (TB) cases diagnosed between February 1, 1993 to January 31, 1994 in Canada were collected prospectively. Proportion of drug-resistant isolates and the factors related to drug resistance were measured.


RESULTS
Of 458 study cases, 40 (8.7%) had resistance to at least one first-line antituberculosis drug, of which 5.9% had mono-resistance, 0.7% had multidrug-resistance(MDR-TB)--i.e., resistance to at least isoniazid and rifampin--and 2.2% had other patterns. The overall prevalence of resistance among the foreign-born cases was 10.6% with the highest level among those who resided in Canada for less than four years (15.5%).


CONCLUSIONS
Canada has a relatively low prevalence of antituberculosis drug resistance and a very low prevalence of MDR-TB. Some new immigrants to Canada may be at higher risk for drug resistance and their initial treatment needs to be tailored accordingly.
Farzad
E
E
Division of Blood Borne Pathogens, LCDC, Ottawa. ezzat_farzad@hc-sc.gc.ca
Holton
D
D
Long
R
R
FitzGerald
M
M
Laszlo
A
A
Njoo
H
H
Fanning
A
A
Hershfield
E
E
Hoeppner
V
V
Allen
E
E
D000293:Adolescent; D000328:Adult; D000995:Antitubercular Agents / Q000494:pharmacology*; D002170:Canada; D019049:Developed Countries; D003906:Developing Countries; D004352:Drug Resistance, Microbial; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D018088:Tuberculosis, Multidrug-Resistant / Q000382:microbiology*
D000995:Antitubercular Agents