STS

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.

The tests are performed using Trueprep AUTO Sample Pre-treatment and Prep kits and Truenat micro-PCR chips.

To detect M. tuberculosis, the Truenat MTB chip amplifies a portion of the ribonucleoside-diphosphate reductase gene, nrdB with a Limit of Detection (LOD) of about 100 Colony Forming Units (CFU)/ml sputum sample.

DNA extraction and detection of M. tuberculosis takes approximately one hour.

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.

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).  

At a DMC, the STS primarily ensures that 

1. All patient services from enrolment to outcomes for a TB patient are completed optimally. This is done by monitoring information submitted by the DMC such as referral for testing, no of people tested, no of people diagnosed with TB, initiated on treatment. 

2. All the patients started on treatment are tested promptly using the appropriate follow-up testing schedule( i.e. at the end of IP and CP). 

3. Maintain profile of the DMC in the Nikshay such as tagging the PHI as DMC, name of contact person and other particulars