Post on 15-Jan-2017
Diagnosis of Tuberculosis Current concepts
Dr A D Deshpande MD (Micro) , MD (Patho)
WHO
Int. Std. of TB Care
Std. of TB Care in India
RNTCP
India (25%)
India = 1500 deaths / day because of Tuberculosis
DiagnosisDisease
60 days
15 New cases
Robert Koch
My name is Koch
World TB day 24 March
March 24 1882 -- Dr Robert Koch discovered TB bacillus
Lab Diagnosis of Tuberculosis
Microbiology Tests
Sputum for ZN stain Culture PCR based Tests
Sputum for ZN stain
2 Samples ( Sensitivity)
• LED microscope• Fluorescent
microscope
Sputum for ZN stain
Culture L J Medium BACTEC MGIT
Culture - BACTEC MGIT
Results : 15 days 42 days
Most Sensitive Test Antibiotic Sensitivity for full 13 drugs
Sample to be sent in Saline
• LINE PROBE ASSAY PCR REC BY RNTCP
• OTHER PCR TESTS DONE BY LABS LIKE RANBAXY AND METROPOLICE
( ALL THESE METHOD NOT VALIDATED BY WHO )
PCR Based Tests
PCR based Tests
Gene Xpert - Fast (90 mins) - Easy to perform - Genotypic Drug Resistance (Rif)- Dead Bacteria can
give Test positive
WHO endorsed Test, 2010
Extra pulmonary TB
Lymphnode – PusCSF Synovial fluidEndometrial tissuePleural fluidAny Pus
•BACTEC MGIT Culture & Sensitivity • Gene Xpert
First do smear for ZN stain
Cost - Subsidized Rates ~ IPAQT (Initiative for promoting Affordable & Quality tests)
• Gene Xpert : 2000 Rs
• Line probe Assay (for Sputum Positive samples Only Via RNTCP) : 1600 Rs
• BACTEC MGIT Culture : 900 Rs
Serum IgG , IgM for TB
by Govt. of India
7 June 2012
TB is a Notifiable Disease
Don’t send patients Blood to Diagnose TB
• Not recommended in Adults by RNTCP• Useful in Children
Tuberculin Test (Mantoux Test)
Tuberculin Test in Vitro = TB GoldSame are IGRA & Quantiferon tests
NOT RECOMMENDED IN ADULTS
TB GOLD is NOT Gold
Latent TB
• Child contacts• All Immunosuppressed – HIV Patients• In US
Diagnosis of Tuberculosis in Pathology
FNAC Histopathology
>15 Days Productive cough / Doubtful Radiological finding - Sputum for ZN stain
Culture (BACTEC MGIT) - Most Sensitive Gene Xpert – Fast No role of Tuberculin Test in Adults Blood is not a sample, Serology is Banned
Take Home Message
Thank you