Smoking and Tuberculosis

Tobacco smoking is injurious to health! Almost every one of us is familiar with an important disclaimer and understands it is a critical massage about your health. However, in order to satiate the never-ending bad habit, most of the people tend to ignore this important life-saving signal. Both, active and passive smoking is leading to causes of preventable death globally. Prolonged smoking can put out you at risk of tuberculosis (TB). This so-called high-status activity and as wrongly advertised marketing gimmick, severely hit young and adults of both genders. There is nothing called as ‘healthy smoking’. Electronic cigarettes loaded with vaporized chemical substances also increase the risk of cancer. They cause a serious lung condition called ‘popcorn lung’.

Effect Of Tobacco Smoking On Lungs

· When the tobacco smoke enters the lungs, it causes the release of free radicals (cell-damaging agents) in the bloodstream that leads to oxidative stress and cellular imbalance in the lungs.

· Smoking damages the linings of alveolar sacs, thereby trapping both the oxygen and carbon dioxide gas within the lungs. The trapped gas severely affects the normal functioning of the lungs. Smoking damages the lungs, incapacitating the natural defense system of the organs. It hinders the ability of alveolar macrophages (defense cells of lungs) to stop the attacking infection.

· Free radicals hamper many metabolic processes. They reduce the production of nitric oxide synthesis (defense messengers), which are responsible for instructing alveolar macrophages to attack infectious microorganisms. Thus, it is rightly said ‘A smokers’ lung is a comfortable house for many infections’.

· Mycobacterium tuberculosis to multiply at rapid growth. All these events provide an ideal condition for deadly and opportunistic pathogens liketo multiply at rapid growth.

· Bronchiolitis obliterans (BO), informally known as popcorn lung, is a disease that results in obstruction of bronchioles, the smallest airways of the lungs due to inflammation, which is a favorable condition of Mycobacterium tuberculosis.

What is Tuberculosis?

Tuberculosis (TB) is an airborne, aerosol-transmitted infectious disease. It is caused by Mycobacterium tuberculosis. Lungs are its primary site of infection. Tuberculosis transpires usually when a person inhales microscopic droplets nuclei containing viable bacteria spread via sneezing, speaking, coughing, etc. from active TB patients.

Mycobacterium tuberculosis precisely affects the lungs. Whereas TB infection spreading to the other organs such as kidney, brain, lymph, bones, spine, etc., is called as extrapulmonary TB. Pulmonary TB happens whenprecisely affects the lungs. Whereas TB infection spreading to the other organs such as kidney, brain, lymph, bones, spine, etc., is called as extrapulmonary TB.





Signs and Symptoms of Tuberculosis -

It is important to notice the early signs and symptoms which includes

Cough for more than 3 weeks

• Chest pain

• Night sweats

• Low-grade Fever

• Coughing up blood





Latent Tuberculosis

Mycobacterium tuberculosis is an opportunistic pathogen. It can remain present in the respiratory tract of a healthy person for a long period of time. This bacterium colonizes the alveolar sacs (airbags present in lungs) and remains in an inactive state (latent form) it is a non-infectious state. It becomes active upon lowering of the host's immunity





Bacterial Entry from Air

TB bacilli are omnipresent. The infection spreads through the air because TB disease primarily affects the lungs. The transmission of Mycobacterium tuberculosis can occur in spite of the minimum duration of exposure to infectious agents. TB bacilli can infect many people in densely crowded places like public transport settings, crowded slums, hospitals and clinics, schools and indoor workplaces.

A healthy, a non-tobacco smoking person is able to mount a strong immune response towards TB infection whereas the immune response of tobacco smoking person can severely struggle against attacking TB infection.





Prevention or Cure - Your Call!

The cornerstone of TB treatment is the regular dosage regimen of antibiotics against Mycobacterium tuberculosis. Antibiotics are prescribed by the doctors according to the stage of TB infection and the level of infection.

Screening and Diagnosis

1. Tuberculin Skin Test (TST) and Interferon Gamma Release assay (IGRA) for Latent TB infection only.

• In TST, the forearm of the patient is injected with a purified protein derivative (PPD) solution. TB infected person will have redness and swelling around the injected area, which is indicative of the presence of TB infection.

• In IGRA, the release of gamma interferon by white blood cells upon exposure to antigens derived from Mycobacterium tuberculosis indicates the presence of TB infection.

2. Imaging test

• Chest radiography X-rays are used to visualize lung abnormalities.

• Computed Tomography (CT) visualizes the lung abnormalities more efficiently than chest Radiology. Magnetic Resonance Imaging (MRI) is the radiation-free alternative for the detection of TB.

3. Mycobacterium Growth Indicator Tube (MGIT) and Drug Susceptibility Testing (DST)

• MGIT technique is used to detect the presence and growth of Mycobacterium tuberculosis. DST resistance of Mycobacterium tuberculosis against the anti-TB drugs.

4. TB-PCR (Polymerase Chain Reaction) –

• It is a rapid molecular technique which uses DNA amplification for the detection of Mycobacterium tuberculosis.

5. GeneXpert (Cartridge based nucleic acid amplification test) CBNAAT

• A molecular technique which rapidly and simultaneously detects Mycobacterium tuberculosis and Rifampicin resistance; a surrogate marker for MDR.

6. Line Probe Assay

• Multidrug resistance TB poses a potential threat to TB control due to its treatment challenges. Line probe assay is a novel technology for rapid detection of anti-TB drug resistance in the first line and second-line drugs.



