Abstract:
Objectives: To determine and document the role of non-tuberculous mycobacteria
(NTM) in TB-like disease morbidity and demonstrate the confusion they cause in the
diagnosis of TB in western Kenya.
Design: A cross-sectional study.
Setting: One provincial and nine District hospitals in western Kenya.
Subjects: Tuberculosis suspects.
Interventions: Sputa from 872 tuberculosis suspects underwent microscopy and culture
on solid and liquid media. The growth was identified using the Hain’s GenoType ®
Mycobacterium CM and GenoType ® Mycobacterium AS kits. Consenting clients were
screened for HIV infection using Trinity Biotech Uni-Gold TM test and positive cases
were confirmed with the enzyme linked immunosorbent assay. A questionnaire was
used to obtain demographic data.
Main outcome measures: ZN smear positivity / negativity; Culture positivity or negativity;
Mycobacterium species isolates (tuberculous or non-tuberculous); HIV status.
Results: Sputa from 39.1% (341/872) of the participants were ZN smear positive,
of these 53.1% (181/341) were culture positive. Only 3.8% (20/531) of the ZN smear
negatives were culture positive. In total 41.4% (361/872) participants were infected
with mycobacteria, of which 44.3% (160/361) were culture negative and 55.7% (201/361)
were culture positive. The culture positives yielded 92.5% M. tuberculosis complex
and 7.5% NTM. The overall prevalence of the NTM disease was 1.72% (15/872).
Conclusion: A low prevalence of NTM pulmonary disease in western Kenya is reported
in this study, but some the NTM disease cases could have been misdiagnosed as TB
cases.
