Presentation on theme: "QUALITY CONTROL ISSUES IN MICROBIOLOGY DR.S.K.BISWAS ASSOC.PROF. & ASST. MICROBIOLOGIST TATA MEMORIAL CENTRE,MUMBAI."— Presentation transcript:
QUALITY CONTROL ISSUES IN MICROBIOLOGY DR.S.K.BISWAS ASSOC.PROF. & ASST. MICROBIOLOGIST TATA MEMORIAL CENTRE,MUMBAI
DEFINITION : Quality assurance (QA) : Defined by WHO as total process whereby the quality of laboratory reports can be guaranteed. right result, at the right time, on the right specimen, from the right patient, with the result interpretation based on correct reference data, and at the right price.
Quality control : Primarily concerns the control of errors in the performance of tests and verification of test results. Must cover all aspects of every procedure within the department. Must be practical, achieveable, and affordable. All materials, equipment and procedures must be adequately controlled. Culture media must be tested for sterility and performance.
Pre-analytical stage : Proper filling of request form : Collection of specimens : Transport of specimens : Accession of specimens :
Unacceptable Samples: Unlabelled, incompletely labeled, mislabeled or mismatched specimen Dry faecal swab Saliva instead of sputum Eye swab that has not been freshly collected Foleys catheter tips, 24 hrs urine Grossly contaminated, leaking specimen.
Quality control of culture media : Aseptic Conditions : Laminar Hoods, Biosafety Cabinets or between burners Sterility control : 48 hrs If > 10%, discard the lot For individual media and biochemicals, positive and negative control organisms New lot of readymade / dehydrated media, BACTEC bottles tested with positive and negative ( uninoculated ) controls Staining techniques and QC of stains
Quality control of Antibiotic Discs : Procured from standard companies Cold chain is maintained New lot check with ATCC strains Weekly check for stabilty
Quality Control of Equipment : Calibration of euipments before put in service and once a year Regular cleaning, servicing and maintenance Daily temperature check with calibrated thermometer Everyday running of controls in serology Testing of retained samples for new lot verification
Quality control surveillance procedures of commonly used microbiology equipment EquipmentProceduresScheduleTolerance limits RefrigeratorsRecording of temperatureDaily2°C to 8°C FreezersRecording of temperatureDaily–8°C to –20°C –60°C to –75° C IncubatorsRecording of temperatureDaily35.5°C ± 1°C Water bathsRecording of temperatureDaily36°C to 38°C 55°C to 57°C AutoclavesTest with spore strip (Geobacillus stearothermophilus) At least weeklyNo growth of spores in sub- cultures indicate sterile run Anaerobic jarsMethylene blue indicator stripWith each useConversion of strip from blue to white indicates low O2 Serology rotorCount revolutions per minuteWith each use180 rpm ± 10 rpm CentrifugesCheck revolutions with tachometerMonthlyWithin 5% of dial indicator setting Safety hoodsMeasure air velocity across face opening Semiannually Or quarterly 50 feet airflow per minute ± 5 feet per minute
Processing of Samples : SOPs for sample processing as per text books Samples processed inside Biosafety Cabinets Minimum but proper media should be used Calibrated loops for quantitative methods Gram stain of every sample Identification, susceptibility testing and reporting of results as per CLSI guidelines QC for oxidase, coagulase, catalase tests done every day HIV testing as per NACO gudelines Positive results confirmed with confirmatory tests Interaction with clinicians about results and additional tests
QC of personnel Continuing education programme( CMEs ) and in-service training Participation in local, regional and national seminars and workshops
External quality assessment scheme (EQAS) EQA scheme for major pathogens like IAMM, CAP Should not be too complicated, costly, or time consuming. Participation in EQA schemes additional to internal QC. EQA scheme monthly or at least four times a year. Inter- laboratory comparision Internal quality assessment (IQA) Regular use of certified reference material, replicate testing, retesting of retained items