Antituberculosis Drug Resistance in the South of Vietnam: Prevalence and Trends

Abstract

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% confidenc 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 significantl ( ) since 1996; there was no increase in the prevalence of MDR. P ! .01 Conclusion. 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 drugresistant TB in this setting.

HIV Infection and Multidrug‐Resistant Tuberculosis—The Perfect Storm

“…Additionally, the mean age of patients with infectious TB has declined over time, and a higher prevalence of anti-TB drug resistance has been associated with younger patients [97,99]. Data from population-based surveys suggest that, in Ho Chi Minh City, MDR-TB prevalence is considerably higher than for the country overall among both new patients (3.8% vs. 2.3%) and previously treated patients (25.0% vs. 14.5%) with TB [97,99,100].…”

“…Additionally, the mean age of patients with infectious TB has declined over time, and a higher prevalence of anti-TB drug resistance has been associated with younger patients [97,99]. Data from population-based surveys suggest that, in Ho Chi Minh City, MDR-TB prevalence is considerably higher than for the country overall among both new patients (3.8% vs. 2.3%) and previously treated patients (25.0% vs. 14.5%) with TB [97,99,100]. Although national estimates of HIV infection prevalence among adults in general and among patients with TB are relatively low, at 0.5% and 3.6%, respectively [11,98], data from ongoing surveillance in Ho Chi Minh City indicate increases in HIV infection prevalence among antenatal clinic attendees and patients with TB, currently 1.5% and 9.8%, respectively (Vietnam Ministry of Health, unpublished data, 2005).…”

Epidemiology of Isoniazid Resistance Mutations and Their Effect on Tuberculosis Treatment Outcomes

“…There are, however, very few studies on the mutations underlying resistance to anti-TB drugs and treatment outcome. We therefore studied the epidemiology of katG and inhA mutations in M. tuberculosis isolates and the clinical characteristics of the respective patients in Vietnam, where the prevalence of smearpositive TB was 197/100,000 in 2006-2007 (24) and resistance to isoniazid is common (16 to 25% in new patients) (25). For this we assessed M. tuberculosis genotype and TB treatment outcomes in association with katG and inhA mutations in a prospective, population-based study.…”

Risk factors associated with kanamycin-resistant tuberculosis in a Beijing tuberculosis referral hospital

“…In addition to some common risk factors observed previously for drug-resistant TB, such as previous history of anti-TB treatment (Suárez-García et al, 2009;Vashakidze et al, 2009), living in an urban or densely populated area (Huong et al, 2006;Vashakidze et al, 2009), being smear-positive for acid-fast bacilli at admission (Shah et al, 2008), and having MDR-TB (Huang et al, 2005;Paramasivan et al, 2010), we further revealed that having ofloxacin-or para-aminosalicylic acidresistant TB, having MDR-TB plus ofloxacin resistance and having poly-resistant TB were also independently associated with kanamycin-resistant TB. These phenomena could be explained by the fact that fluoroquinolones (such as ofloxacin and levofloxacin) and para-aminosalicylic acid have been more frequently prescribed for treating repeat cases and suspected MDR-and poly-resistant TB cases.…”