Epidemiology and genomics of Mycobacterium tuberculosis in TB/HIV co-infection in Vietnam

Abstract

TB and human HIV infection have mutually detrimental effects that complicate patient management and global TB control efforts. The overall aim was to improve our understanding of the TB epidemiology, drug resistance profile, and transmission dynamics among people living with HIV in Vietnam. The global epidemiology of TB, HIV and TB/HIV co-infection in low and high incidence countries with a specific focus on the Asia-Pacific region and relevant disease trends within Vietnam was described. Findings from a retrospective study with 200 M. tuberculosis isolates from TB/HIV co-infected patients in Ho Chi Minh city between 2009 and 2014, showed that TB/HIV co-infection in Vietnam was associated with high rates of drug resistant TB up to 42.0%. Beijing and Indo-Oceanic lineage strains were most common in those patients. M. tuberculosis transmission among people living with HIV appeared to be limited, with most transmission occurring within the community. There were high rates of transmitted drug resistant TB among the transmission clusters. The prospectively with 202 patients validated the findings from the retrospective study and to assess both TB and HIV risk factors among TB/HIV co-infected individuals in Vietnam. Most patients were young males, especially in Hanoi where intravenous drug use was a major risk factor for HIV acquisition. TB risk factors included delayed ART initiation, limited use of TB preventive therapy, high rates of cigarette smoking and substance abuse and possible exposure in drug rehabilitation centres. Most cases were severely immune compromised at the time of TB, and HIV, diagnosis. Beijing lineage strains predominated in Hanoi and Ho Chi Minh city. There was no indication of large scale nosocomial transmission. The findings should help to explain the dynamics of TB disease in HIV positive people, improve the care of TB/HIV co-infected patients and the control of TB transmission within Vietnam, and encourage earlier ART initiation and the use of TB preventive therapy in HIV-infected individuals according to WHO’s guidelines.