As TB is an airborne infection, TB bacteria are released into the air when someone with infectious TB coughs or sneezes. The risk of infection can be reduced by taking simple precautions:
Figure: Measures for control and prevention of tuberculosis
Extrapulmonary TB (EPTB) is TB involving any part of the body other than the lungs, e.g., pleura, lymph nodes, abdomen, genitourinary tract, skin, joints, bones, meninges and other sites. A case of Presumptive Extra Pulmonary TB is identified when they exhibit symptoms and signs suggestive of EP TB.
Symptoms of EP TB are dependent on the site of TB as illustrated below.
Pulmonary TB(PTB) is primarily involves lungs. Screening should be done for the following symptoms:
Figure: Signs and Symptoms of active TB
Regular screening of Presumptive TB cases with unexplained cough of any duration should be done and checked for:
Health Volunteers
Figure: Role of Health Volunteers
Resources:
After exposure to infective droplets containing M.TB, only a small proportion gets infected and further progresses to active TB disease.
Presumptive TB case refers to a patient who presents with symptoms or signs suggestive of TB disease (previously known as a TB suspect) and where further diagnostic workup including bacteriological investigation is required.
Presumptive TB can be categorized into
Presumptive Pulmonary TB (P TB) - Symptoms are directly related to lungs (Cough, hemoptysis)
Presumptive Extra Pulmonary TB (EP TB) - Symptoms/ signs are specific to an extra pulmonary site (example: Lymph node swelling)
The National Tuberculosis (TB) Elimination Program (NTEP) has a network of Nucleic Acid Amplification Tests (NAAT) laboratories coupled with Designated Microscopy Centers (DMCs) to form the backbone of the diagnostic component of TB services.
Nucleic Acid Amplification Tests (NAAT) laboratories includes Cartridge-based NAAT (CBNAAT) and TrueNat tests. These tests detect tuberculosis as well as rifampicin resistance and are more sensitive than smear microscopy.
NTEP laboratory network is comprising of National Reference Laboratories (NRLs), state level Intermediate reference laboratories (IRLs), Culture & Drug Susceptibility Testing (C & DST) laboratories and peripheral level laboratories. Peripheral level laboratories consist of designated microscopy centres (DMCs) and NAAT labs.
NTEP has a quality assured laboratory network for bacteriological examination of sputum in a 3-tiered system.
Culture Drug Susceptibility Testing (CDST) is a growth-based phenotypic method used to check the susceptibility of Mycobacterium tuberculosis strains to various first and second line anti-TB drugs. Mycobacterial resistance to a particular drug is identified if there is growth observed in culture in presence of that drug.
