A high tuberculosis and human immunodeficiency virus co-infection rate and clinical significance of non-tuberculous mycobacteria in Western Kenya

Tuberculosis (TB) and human immunodeficiency virus (HIV) co-infection has a global prevalence with high morbidity and mortality rates. Non-tuberculous mycobacteria (NTM) have emerged as opportunistic pathogens among HIV/AIDS patients. Ziehl Neelsen smear microscopy initially used in the diagnosis of TB fails to differentiate between Mycobacterium tuberculosis from NTM. The aim of this study was to determine TB-HIV co-infection rate and the clinical significance of NTM in western Kenya. Sputa from 872 TB suspects underwent microscopy and culture on solid and liquid media. Isolates were identified as M. tuberculosis or species of NTM using Hain's GenoTyper Mycobacterium CM/AS Molecular Genetic Assay. Blood samples from 695 out of the 872 TB suspects enrolled into the study were screened for HIV infection using Uni-Gold rapid test and positives confirmed with enzyme linked immunosorbent assay. A questionnaire was used to collect demographic of the TB suspects. A total of 263 TB cases were among those tested for HIV and 41.8% were co-infected. The high TB-HIV co-infection rate observed in this study calls for strengthening of TB and HIV/AIDS collaborative activities to reduce morbidity and mortality among TBHIV/AIDS patients. The NTM played a significant role in causing TB-like disease which was misdiagnosed as TB. Large case-control studies are imperative to identify risk factors and determine the contribution of NTM to TB-like disease among HIV/AIDS patients.