Mycobacterium tuberculosis and non-tuberculous mycobacteria isolates from HIV-infected patients in Guangxi, China.

BACKGROUND: Tuberculosis (TB) remains the leading cause of death among human immunodeficiency virus (HIV) infected persons. The prevalence of infection with Mycobacterium tuberculosis and non-tuberculous mycobacteria (NTM) in HIV-infected patients in China is unknown.

OBJECTIVE: To estimate the prevalence of M. tuberculosis and NTM in HIV-infected patients in Guangxi Province, determine their drug resistance profiles, and evaluate the genotype patterns of M. tuberculosis strains.

DESIGN: Samples were collected from two HIV designated hospitals in Guangxi Province between 2005 and 2008. HIV-infected patients who were culture-positive for mycobacteria were included. Drug susceptibility testing was performed for mycobacterial isolates. NTM species was identified by sequencing, and M. tuberculosis isolates were genotyped using the variable number of tandem repeats method.

RESULTS: M. tuberculosis and NTM were identified in respectively 117 (53%) and 102 (47%) HIV-infected patients. Drug resistance was found in 27% and multi-drug-resistant TB (MDR-TB) in 11% of the patients with TB. Previous treatment for TB was significantly associated with MDR-TB. Twenty (17%) TB patients belonged to eight VNTR-defined clusters.

CONCLUSION: The high frequency of NTM among HIV-infected patients raises concerns about accurate species identification before the determination of appropriate treatment. The potential for TB transmission exists among HIV-infected patients. Intensified screening and effective treatment of TB-HIV co-infected patients is urgently needed.