Quality assessment of sputum for Acid Fast Bacilli(AFB) test in microbiology laboratories before and after implementation of Standard Operating Procedure (SOP): a comparative study

Aims: To evaluate the present status of microbiology laboratory by comparing the test results of investigator with that of laboratory staff for sputum for Acid Fast Bacilli (AFB) withZiehl-NeelsenStaining (Z-N Staining) at primary and secondary level andto assess the present status of a microbiology laboratory for sputum for Acid Fast Bacilli (AFB) withZiehl-NeelsenStaining (Z-N Staining) at tertiary level.Material and Methods:Type of study : Cross sectional, descriptive type of study.Place of study: Department of Microbiology of Dhaka Medical College,Narsingdi Sadar Hospital,Narsingdi,PolashUpzilla Health Complex ,Polash, Narsingdi andDOTS centers.Duration of study: From July, 2007 to June,2008Method of sampling: Non probability, purposive and convenient samplingSample Size: Sputum for AFB: 300 sputum samples were collected for detection of AFB by direct Z-N staining, Z-N staining after bleach centrifugation and Auramine phenol staining before implementing SOP. After following SOP 150 sputum samples were collected and tested in direct Z-N method.Results: In the present study, before SOP out of 100 sputum smear at each level, discrepancy was found in 3% cases at primary level, 2% cases at secondary level and 1% case at tertiary level.After following SOP out of 50 sputum smear at each level, discrepancy was reduced to 2% cases at primary level and no discrepancy was found at secondary and tertiary level.Conclusion: Each laboratory must have SOP for laboratory testing to set the minimum acceptable standard for every test in order to improve and maintain the quality of laboratory services