A state-of-the-art liquid tuberculosis culture testing facility is being readied at the Department of Microbiology at K.A.P Viswanatham Government Medical College.
Being set up at a cost of ₹1.2 crore from the National Health Mission, the laboratory will help screen drug-resistant TB patients, and prevent spread of the infection, doctors said.
While a lab at the medical college has been conducting solid culture tests for tuberculosis, with the new facility, set up in a bio-safety chamber constructed solely for this purpose, the technicians will be able to process tests for multi-drug resistant tuberculosis patients who were being referred to Chennai so far.
As many as 960 samples, in a liquid medium, can be tested in one go as a Mycobacteria Growth Indicator Tube (MGIT) machine has been set up at a cost of ₹50 lakh. “This is the gold standard in TB testing. A collected sample is introduced to a liquid medium and if bacteria is present, it will consume oxygen in the liquid and grow. This is the basic principle through which the test is done,” K. Lakshmi, Head, in charge, Department of Microbiology, told The Hindu.
To test for drug-resistant TB, at this stage, first-line drugs, which are the first prescribed medicines given to patients diagnosed with the infection is introduced. “In some patients, when these medicines are consumed for over six months, the body tends to become resistant to it. For them, despite treatment, the rate of recovery is slow,” she said. When the bacteria in the liquid medium continues to grow even after the drug is introduced, it indicates that it is drug-resistant TB.
Following confirmatory tests, the patient from whom the sample was lifted will be treated accordingly. Test results are uploaded to Nikshay, a unified portal for TB patient management in the country.
960 samples
As many as 960 samples can be processed in one go and results for positives can be acquired within a week. “TB is a slow-growing bacterium. Until recently, cultures were looked at individually under a microscope through an acid-fast bacteria test at various District Microscopy Centres. However, it only had a 60% accuracy rate. With the new facility, it will be near perfect,” Dr. Lakshmi said.
The entire facility, equipped with three individual bio chambers, is a fully bio-safe lab with negative pressure to ensure the droplet does not affect the technicians. It has other control measures, including a disinfectant shower. “Patients can be diagnosed quickly and treatment started to save lives,” she said.
Seven technicians - four will be recruited under National Health Mission, will soon join the team led by S. Vanathi, Assistant Professor, Department of Microbiology. Dr. Vanathi underwent special training to lead the team. “We are collecting 100 samples to run a quality control test. Once the test is completed, we will begin testing,” Dr. Lakshmi said. The facility is expected to be inaugurated by the Chief Minister soon.
