MDCH STATE LABORATORY TUBERCULOSIS TESTING Specimens/Tests/Reports Dale E. Berry, B.S. TB Lab Manager (517) 335-9637 BerryD@Michigan.gov Title slide
MDCH STATE LABORATORY LANSING, MICHIGAN Picture of lab.
TYPES OF SPECIMENS SPUTUM PULMONARY ASPIRATES GASTRIC ASPIRATES BODY FLUIDS TISSUES BLOOD FECES OTHER
SPECIMEN QUALITY Three specimens on three successive days Early morning specimens (First thing out!) Adequate specimen volume (>7 ml) Sputum not saliva (epithelial cells?) Condition of specimen (pH, etc.) Appropriate specimen container Complete and accurate information Proper packaging (i.e. US Postal Service) “Prompt” delivery to MDCH
MDCH – TESTS for AFB AFB Slide Examination Direct Amplified Genetic Probe (M.tb complex) Direct Susceptibility AFB Culture and Isolation Pre-Identification (Genetic Probe/HPLC) Final Identification (Biochemical, etc.) Pre-Indirect Susceptibility (Primary Drugs(1st Line)) Final-Indirect M.tb. Susceptibility (2nd/3rd Line) MOTT Susceptibility DNA Fingerprinting
AFB Slide Examination Least Sensitive AFB Test Requires 100,000 AFB/ml Requires an adequate specimen Negative smear – Does not rule out AFB Positive smear – AFB present (viability?) AFB Positive = Mycobacterium spp., etc. Help support TB diagnosis Quantitation: Positive/Positive Few/ Negative
MTD – Direct Amplified Probe Rapid Test & Sensitive Specific – M.tuberculosis complex Not a test of viability or cure Pulmonary Specimens only Specimen processing @ MDCH only Reduces subsequent test sensitivity Delays culture & susceptibility results 97%/100% Sensitive/Specific
AFB Culture and Isolation More sensitive than slide Requires only 10 AFB/ ml of specimen AFB Growth in 1-2 weeks (Bactec) Genetic Probes and HPLC Rapid ID Fewer AFB/ml – Delayed growth “AFB Growth” required for other tests Mixed cultures require subcultures
Preliminary AFB Identification Genetic Probe/HPLC One day after culture positive Probe for M.tuberculosis complex HPLC for MOTT Helps confirm antibiotic therapy
Preliminary TB Susceptibility Approximately 1 week after pre-ID Tests “Primary” anti-Tuberculosis drugs Direct and Indirect testing Bactec methodology Confirmed by“Proportion Plate Method”
Final AFB Identification Required to differentiate M.tb complex Required to confirm HPLC ID’s Required to clarify unresolved ID’s Requires additional time (3-4 weeks) Final Report ASAP
TB Susceptibility - Additional Proportion Plate Method Requires additional 3 weeks To increases choices for therapy Performed for drug resistant TB cases Tests 2nd and 3rd line antibiotics Confirms results of “Broth Method”
MOTT Susceptibility Testing Test according to latest NCCLS Guidelines M.avium complex - Clarithromycin M.kansasii/M.marinum - Rifampin/Ethambutol M.fortuitum/M.chelonae – Refer to CDC Additional antibiotics not offered by MDCH Refer to National Jewish Hospital in Denver, Colorado
RFLP – DNA Fingerprinting For TB outbreak investigations Check for “reactivation vs re-infection Check for lab cross-contamination Performed on approved requests only
MDCH AFB TEST TIME-LINE PRE ID PROBE HPLC SPECIMEN SLIDE MTD CULTURE TB SENS FINAL ID FINAL CULT 24 HRS 48 HRS 7-10 DA 12-18 DA 3 WKS 6 WKS 8-14 DA AFB FOUND NOT FOUND MYCOBACTERIUM FOUND FINAL ID SPECIES CONFIRMATION TB complex RNA DETECTED NOT DETECTED PRELIM ID M.tb complex NOT M.tb complex MOTT SUSCEPTIBILITY PRIMARY ANTIBIOTICS MYCOBACTERIUM NOT FOUND REFERRED CULTURE 24-48 HRS 7-10 DA 2-3 WKS
QUESTIONS > CALL MDCH TB Laboratory Dale Berry Lab Manager @ (517) 335-9636 Steve Church Microbiologist Angie Schooley Microbiologist Jolene Vanneste Microbiologist
CONTACT INVESTIGATION Complete Networking TB CONTACT PRIVATE LAB SLIDE CULTURE PRELIM ID TB PATIENT SYMPTOMS HEALTH CARE PROVIDER (DR) DIAGNOSIS COUNTY HEALTH DEPARTMENT TREATMENT CONTACT INVESTIGATION STATE LAB SLIDE MTD CULTURE IDENTIFICATION DNA FINGERPRINT STATE DISEASE CONTROL