Molecular identity of mycobacteria isolates in new cases of pulmonary tuberculosis patients in Kisumu County, Western Kenya

Abstract

Pulmonary tuberculosis (TB) remains one of the most challenging diseases to control in the world today and it has become a major global health problem especially in immunocompromised people such as HIV/AIDS. The problem is compounded by the emergence of non-tuberculous mycobacteria (NTM) of which its treatment is not directly analogous to that of MTB. Objective: This study determined the identity of Mycobacteria isolates in new cases of human pulmonary TB patients. Methods: It was a cross-sectional study that involved 316 confirmed new cases of pulmonary TB attending JOOTRH and Kisumu County Hospital. Sputa specimen was cultured in MGIT liquid culture medium. The isolates were identified to species level using GenoType® Mycobacterium CM/AS and MTBC Assay from Hain Lifescience Germany. Results. Of the 316 culture positive isolates, 91.8% were identified as MTBC and 8.2% were NTM species. Of the 290 MTBC, three different species were identified, 97.6% were M. tuberculosis, 1.7% were M. africanum and 0.7% were M. bovis. The Fisher’s exact test was used to assess the associations between patient characteristics and MTBC species identified showed that age category of patients less than 35 years and above 35 years were statistically significant with MTBC species (p=0.020). While sex was not statistically significant with MTBC species (p=0.696). Four different NTM species were identified as 61.5% M. intracellulare, 19.2% M. abscessus, 11.5% M. kansasii and 7.7% M. fortuitum. The Fisher’s exact test done to assess the associations between patient characteristics and NTM species was identified. Age category (p=0.608) and sex (p=0.182) of patients was not statistically significant to NTM species. Conclusion: There is a need for routine speciation among members of the MTBC and NTM as it is an important prerequisite for the proper management of patients with mycobacterial infections.