DR-TB Coordinator

Culturing TB Bacilli is well known and historic method for detection/ confirmation of Tuberculosis. It is a highly sensitive and specific phenotypic test; it can detect even a few viable bacilli in the sample (Upto 10 Colony Forming Units- CFUs). TB bacilli multiply in the culture and form colonies of TB bacilli which can are easily be identified.

Based on the growth media used Culture is divided in to two types, Solid and Liquid Culture methods. Types Culture:

Line Probe Assay (LPA) is a rapid molecular test available at centralised laboratories.

The assay is based on Polymerase Chain Reaction (PCR) that can simultaneously detect Mycobacterium tuberculosis complex as well as drug sensitivity to anti-TB drugs.

Microscopy is a TB diagnostic technology that utilizes the acid-fastness property of Mycobacterium tuberculosis to visualize it under a microscope. Results of sputum smear microscopy can either be smear-negative, or smear-positive (with various grades). 

Advantages:

• It is currently the most accessible and cheapest TB diagnostic test available under National TB Elimination Programme (NTEP) in India.
• It has the shortest turnaround time for diagnosis.
• It has high specificity. 

Limitations:

Nikshay is an Integrated ICT system for TB patient management and care in India. Nikshay was launched in 2012 and since then, various improvements have been made in the system.

Nikshay provides-

National Tuberculosis Elimination Programme (NTEP) strives for all presumptive TB patients to be microbiologically confirmed. Under NTEP, the acceptable methods for microbiological diagnosis of TB are: 

Screening for active tuberculosis (TB) a process to filter out people who are less likely to have TB, from a group. Screened positive people are likely to have TB and are confirmed subsequently using a TB diagnostic test. This will allow finite diagnostic testing resources to be used on the remaining.

• TB Infection (or previously known as Latent TB infection) is a stage in between uninfected and having active TB. In this stage the person has no symptoms and can only be identified using laboratory tests.

• The vast majority of infected people may never develop TB disease. However, to achieve TB elimination, it is important to treat TB infection in people at risk of developing active TB disease.

The eligibility for TB Preventive Treatment (TPT) relies on ruling out active TB among individuals and groups who are known to have a high risk of acquiring TB. 

Prioritization of the target population for TPT is based on elevated risk of progression from infection to TB disease or increased likelihood of exposure to TB disease: At-risk populations include:  

Cartridge Based Nucleic Acid Amplification Test (CBNAAT) is a rapid molecular diagnostic test. It is used for diagnosis of Tuberculosis (TB) and Rif-resistant Tuberculosis (RR-TB) in NTEP. Results are obtained from unprocessed sputum samples in about 2hours which helps in early detection and treatment of TB patients. 

India has vast number of CBNAAT laboratories which are utilized for TB/RR-TB detection and Universal Drug Susceptibility Testing (UDST) under the National TB Elimination Program (NTEP).  

Bidirectional screening is a method to identify cases in diseases which have predisposition to each other or has a significant influence on each other. For example TB and HIV, where having HIV increases risk of developing TB and cases with TB would have poor outcomes if co-infected with HIV.

Screening for TB is done through four-symptoms complex based screening or through Chest X-ray. Screening for the linked disease is carried out as per the policies of the corresponding health program.