Tuberculosis is an age old disease and still continues to claim over 1000 lives every single day. Tuberculosis continues to be a major health burden and is one of the leading causes of deaths in the country. Adding to the woes is the worrisome trend of extremely drug resistance and total drug resistant strains.
TB is a contagious disease and hence complete and accurate diagnosis becomes paramount for infection control, proper disease management and better clinical outcomes.
Types of Tuberculosis:
- Mono-resistant: Resistant to a single drug
- Poly-resistant: Resistance to more than one drug but not to the combination of Isoniazid and Rifampicin
- Multi-resistant (MDR): Resistance to at least Isoniazid and Rifampicin
- Extensively Drug Resistant (XDR) : MDR plus resistance to fluoroquinolones and at least 1 of 3 injectable drugs (Amikacin, Kanamycin, Capreomycin)
- Extremely Drug Resistant (XXDR): TB which is resistant to all first and second line TB drugs
The WHO has set protocols for TB diagnosis and four tests have been approved: LED microscope, liquid culture and two molecular tests viz. Gene Xpert and Line ProbeAassay.
Liquid Culture still continues to be the gold standard and takes up to 2 weeks for a report to be produced. Liquid Culture gives complete diagnosis and indicates resistance to first line and second line of drugs.
Gene Xpert is another test that has been widely used since 2014 owing to a faster turnaround time. Results are available within 2 hours and it is possible to determine accurately the presence of tuberculosis and if it is Multi-resistant; however the GenExpert test does not give any insights on resistance to drugs other than Rifampicin or second line drugs. If the GenExpert report suggests Multi-drug resistance, the patient needs to undergo Liquid Culture test that will decide the course of treatment.
Commenting on World Tuberculosis Day, Dr Shamma Shetye, Chief of Lab Services, Metropolis Healthcare said “We offer Gene Xpert test through our tie-up with IPAQT. Of all the samples tested at our center, about 25% tested positive for tuberculosis infection and off all positive detections, 25% were resistant to Rifampicin. GenXpert is slowly becoming a standard test for tuberculosis. It is important to know if you are suffering from Primary or MDR TB before treatment is started.” We have validated Genexpert for extrapulmonary samples as per WHO guidelines and find it to be very promising. Also in the light of MDR and Pre-XDR; a strategy of combining Rapid AFB culture and Genexpert proves most efficient for better diagnosis and management.
Awareness is the first step towards good health. In infections such as Tuberculosis, it is important that patients are fully aware of the burden of the disease, the types of tests needed, the drugs used for treatment, duration of treatment, disease monitoring and treatment progression. It is heartening to note that mortality from Tuberculosis has come down in India in the past decade but the infection spread is yet to be brought under control. Health awareness on a large scale is required to tackle a burden like Tuberculosis. We have seen India take strides in tackling Polio and Leprosy; the nation now needs to take up TB control on priority.