TAS TB Screening in the ART clinic 2015

A detailed understanding of where, when and how Mycobacterium tuberculosis (Mtb) transmission is occurring in communities with a high HIV/tuberculosis burden is urgently required in order to effectively implement interventions to break the transmission cycle. Antiretroviral (ART) clinics are a potential area of high transmission, with many opportunities for infectious and vulnerable individuals to come together in close proximity especially as TB and HIV services become more integrated. Although ART reduces the risk of TB, risks remain raised, and about half the newly diagnosed HIV positive TB patients are already on ART. The extent to which Mtb transmission occurs in these clinics, and how much can be prevented by active screening is not known. Active screening should detect TB at an earlier stage in the disease, improving outcome and reducing transmission. This study will be based in an HIV-prevalent rural community in Malawi as part of a long-term population-based study of tuberculosis and will complement other ongoing studies examining transmission (eg NHSRC #944). The specific objectives are to institute regular intensive screening for TB in ART clinics; to identify the extent of transmission that has led to active disease in clinic attendees and their guardians; and to estimate the proportion of TB in the area that is attributable to transmission in these clinics. Isolates from all TB patients will have mycobacterial DNA extracted and subjected to strain identification and whole genome sequencing as part of broader epidemiological studies of TB (NHSRC # 424).