"All WHO-approved latest TB diagnostic tests are available free of cost in public sector laboratories across the country. The challenge was to make these WHO-approved TB diagnostic tests available and affordable in accredited private laboratories as well. What made IPAQT a good practice example is that it helped WHO approved diagnostic manufacturers and accredited private laboratories in India to come to an agreement that was important to address the issue of suboptimal diagnosis of TB in private sector. Diagnostic manufacturers agreed to provide WHO recommended TB diagnostic equipment such as Gene Xpert, Line Probe Assays (LPAs), Liquid Culture or Fluoroscent LED Microscope and requisite supplies to private accredited laboratories at public sector pricing. Private accredited laboratories that are part of IPAQT network agreed to pass on the same financial benefit to the patient who is seeking test for TB and agreed at a maximum price they can charge for such tests (which was broadly half of market price). Private laboratories also agreed to notify TB cases they were testing to the RNTCP."
As of now, 95 private laboratories across India are offering WHO approved tests at 50% lesser price at least than the market price. More than 100,000 tests have been done in the last two years in these laboratories, said Dr Pai.
Upgrade conventional microscopy to LED!
"RNTCP is heavily relying on conventional sputum smear microscopy (done by Ziehl-Neelsen staining) which is not as sensitive as LED microscopy. We need to upgrade microscopy centres across the country to at least use LED fluoroscence microscopy (done by auramine-rhodamine staining). Also we need to scale up capacity in the country to increasingly provide DST along with TB testing."
"Even if we do best job of smear microscopy we will only pick up 60-70% of TB. Its sensitivity cannot go up anymore than that. If smear microscopy has to be done then at least laboratory should be equipped with LED fluoroscence microscope, trained technician, and EQA programme also have to be in place. Studies show that LED fluoroscence microscope picked up 20% more cases than conventional microscopy done in India" said Dr Pai.
Breakthroughs in TB diagnosis
Gene Xpert, a cartridge-based nucleic acid amplification test (CB-NAAT), is indeed one of the major game changers in TB diagnostics globally. "Novelty is not that it is polymerase chain reaction (PCR) technology based test, as PCR is not new and has been around for long time. But since it is completely automated PCR, that is why it is novel and perhaps the single biggest advancement in TB diagnostics!"
Gene Xpert gives results within 100 minutes whether a person has TB or not, and if so, then whether a person is resistant (or sensitive) to Rifampicin.