The Beijing genotype is associated with young age and multidrug-resistant tuberculosis in rural Vietnam

Abstract

Background: Associations between multidrug resistance and the Mycobacterium tuberculosis Beijing genotype have been described mainly in populations with poor tuberculosis (TB) control such as prisons and inner cities, and may reflect shared risk factors rather than a biological association.

Objective: To study the association between genotype and drug resistance among TB patients in a population with adequate TB control.

Setting: Three rural districts in Vietnam. The study was performed at the Pham Ngoc Thach Tuberculosis and Lung Disease Hospital, Ho Chi Minh City, and the Tien Giang Provincial Tuberculosis and Lung Disease Hospital, My Tho, Vietnam.

Methods: Pretreatment sputum specimens were collected for culture, drug susceptibility testing and spoligotyping of all sputum smear-positive pulmonary TB patients consecutively diagnosed over a 3-year period.

Results: Beijing genotype infections were observed in 614 of 1744 (35%) patients. Beijing strains were more common among female (adjusted odds ratio [aOR] 1.4, P = 0.005), young (aOR 2.8, P < 0.001) and previously treated patients (aOR 2.4, P < 0.001). The Beijing genotype was associated with any resistance (aOR 3.7, P < 0.001) and multidrug resistance (aOR 6.8, P < 0.001) among new patients, and with any resistance (aOR 2.7, P = 0.005) but not with multidrug resistance (aOR 1.4, P = 0.545) among previously treated patients.

Conclusion: In Vietnam, Beijing genotype is associated with young age and in new patients with multidrug resistance despite adequate TB control, suggesting a biological association. This potentially undermines the effectiveness of TB control in countries where Beijing genotype infections are common.