Effect of Bleach on the Diagnosis of <i>Mycobacterium tuberculosis</i>

Abstract

Direct smears microscopy for acid-fast bacilli (AFB) is one of the easily applied laboratory techniques for diagnosis of tuberculosis in most medical laboratories especially in developing countries. Bleach microscopy techniques has been assessed in different settings as a potential alternative for the diagnosis of tuberculosis. This study investigated the effect of bleach on the diagnosis of Mycobacterium tuberculosis in a hospital (Direct Observation Therapy centre in Central Hospital, Benin City, Edo State, Nigeria). Sixty (60) sputum samples were collected from individuals that showed symptom of tuberculosis which comprises of new and follow up cases among patients with age >15 regardless of gender. The sputa samples were analyzed by two techniques using direct smear microscopy and bleach commonly used in household. Result revealed that of the 60 sputum samples 32 (representing 53.3%) were positive to AFB (for direct microscopy techniques) and 32 were also positive to AFB when household bleach techniques were applied. Of the 32 positive result, 7 (21.9%) smears graded as + when direct microscopy techniques were applied appeared scanty and 10 (31.3%) graded as ++ were decreased to +. Furthermore, 15 (46.9%) smears graded as +++ decreased to ++. The bleach technique for the diagnosis of Mycobacterium tuberculosis improves the field view. Hence there is need for more research on the use of bleach for the detection of Mycobacterium tuberculosis .