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Staff working with patient specimens and live mycobacterial cultures must operate under appropriate biosafety conditions with adequate infection control measures in place, including staff health checks.

For the safety of personnel working in TB labs, the following factors must be considered to avoid the risk associated with pathogenicity and transmission of TB bacilli.

The 4 key factors that must be considered during risk assessment of TB labs include:

Risk assessment is the process that enables the appropriate selection of microbiological practices, safety equipment, and facility safeguards that can prevent laboratory-associated infections (LAIs). 

The figure below shows a flowchart that presents the risk assessment process for a biological hazard.

Figure: Risk assessment process for a biological hazard

Risk assessments for TB laboratories should consider:

The Results for Second Line Probe Assay (SL LPA) are entered in:

• Culture and Drug Susceptibility testing (CDST) register
• Nikshay-CDST module
• Request Form for examination of biological specimen for TB
  • The fields entered are shown in Figure 1

Figure 1: Result entry for Second Line LPA
Source: TOG Annexure

Results of the First-line Line Probe Assay (FL-LPA) are entered in Nikshay and downloaded as the culture and drug susceptibility test (CDST) register.

Information on the patient, facility, reason for testing and test results are captured, and are shown in the table below.

MGIT 960 media quality control (QC) is to be done upon receipt of a new shipment or lot number. This includes checking the media visually and by growing control strains of Mycobacterium. Steps include:

• Visually check the tube for​:
  • Turbidity/contamination ​
  • Expiry date​
  • Breakage ​
  • Transport condition​

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The MGIT 960 is a sensitive instrument to be operated by trained and competent staff. To carry out the liquid culture using this instrument, following steps need to be performed.

Table: Operation of the MGIT 960 Instrument

Step 1   To load the tubes, open the desired drawer.    Once the drawer is open, select the desired workflow on the LCD display, in this case, Tube Entry.

Smear microscopy and culture play an important role in monitoring the response to TB treatment. In NTEP, smear microscopy and culture has been prescribed to monitor the treatment response and at specific time points based on different treatment regimens. The programme also explains the actions that need to be taken based on the follow-up results.

Monitoring of tuberculosis treatment is shown in the table below.

The disposable, single-use CBNAAT cartridge holds the samples and reagents to be processed in the CBNAAT System. The main cartridge components are described below, and shown in the figure below.

The CBNAAT module contains components that enable automated sample processing in the cartridge, and filling of the tube with the sample-reagent mixture for Polymerase Chain Reaction (PCR), followed by PCR amplification and detection.

The structure of the CBNAAT module is described below and shown in Figure 1:

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