Antituberculosis drug resistance in the south of Vietnam: prevalence and trends.
BACKGROUND
There is limited evidence that the DOTS (directly observed therapy, short course) strategy for tuberculosis (TB) control can contain the emergence and spread of drug resistance in the absence of second-line treatment. We compared drug-resistance levels between 1996 and 2001 in the south of Vietnam, an area with a well-functioning DOTS program.


METHODS
Sputum specimens were collected from consecutively diagnosed patients with smear-positive TB at 40 randomly selected public TB clinics. Mycobacterium tuberculosis isolates were tested for susceptibility to first-line drugs.


RESULTS
Among 888 new patients in 2001, resistance to any drug was observed in 238 (26.3%), resistance to isoniazid was observed in 154 (16.6%), resistance to rifampin was observed in 22 (2.0%), resistance to ethambutol was observed in 12 (1.1%), resistance to streptomycin was observed in 173 (19.4%), and resistance to both isoniazid and rifampicin (multidrug resistance [MDR]) was observed in 20 (1.8% [95% confidence interval, 1.0%-3.3%]). Among 136 previously treated patients in 2001, any resistance was observed in 89 (62.9%), and MDR was observed in 35 (23.2%). The prevalence of any drug resistance and of streptomycin resistance among new patients had decreased significantly (P<.01) since 1996; there was no increase in the prevalence of MDR.


CONCLUSIONS
The prevalence of drug resistance decreased despite high initial levels of resistance to isoniazid and streptomycin and despite the absence of second-line treatment. Therefore, a DOTS program can contain drug-resistant TB in this setting.
Huong
Nguyen T
NT
National Hospital of Tuberculosis and Respiratory Diseases, Hanoi, Vietnam.
Lan
Nguyen T N
NT
Cobelens
Frank G J
FG
Duong
Bui D
BD
Co
Nguyen V
NV
Bosman
Maarten C
MC
Kim
Sang-Jae
SJ
van Soolingen
Dick
D
Borgdorff
Martien W
MW
D000293:Adolescent; D000328:Adult; D000368:Aged; D000995:Antitubercular Agents / Q000494:pharmacology*; D003625:Data Collection; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D015995:Prevalence; D012307:Risk Factors; D012424:Rural Population; D014376:Tuberculosis / Q000188:drug therapy* / Q000382:microbiology*; D014505:Urban Population; D014744:Vietnam / Q000453:epidemiology
D000995:Antitubercular Agents