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 Tuberculosis is an infectious airborne disease that majorly affects the lungs and pleurae but may also involve other parts of the body, caused by a bacterium called MYCOBACTERIUM TUBERCULOSIS. Related to mortality TB is the most common disease worldwide.

  • CAUSATIVE AGENT OF TB: TB is caused by MYCOBACTERIUM TUBERCULOSIS. It is an obligate aerobe hence causing disease in highly oxygenated tissue like the upper lobe of the lungs and kidneys. It has mycolic acid n their cell wall that make it resistant to acids, alkalis, and dehydration and therefore survives in dried expectorated sputum, hence can easily be transmitted via aerosol.
  • TRANSMISSION OF DISEASE: M.Tuberculosis transmitted from person to person by respiratory aerosol generated by coughing of smear-positive person and initially infects the lungs. It resides in the reticuloendothelial cells i.e., macrophages. Humans are the reservoir of M. Tuberculosis, and we are more likely to get an infection from the person we spend time with.
  • PATHOGENESIS OF TB: Infection is initiated when someone inhales the nuclei of tubercle bacilli, it reaches the alveoli of the lungs, it is then ingested by alveolar macrophages which inhibit most of them. Those bacilli that are left behind, multiply intracellularly and are released when the macrophages die. They spread by lymphatic route or through the bloodstream to more distant tissues and organs like regional lymph nodes, the apex of the lung, kidneys, brain, and bone). This process of distribution prepares the immune system for a systemic response. During a three-to-eight-week period, hypersensitivity occurs after infection, indicating the body’s cellular response and during that time, the skin reaction test will be positive showing the existence of latent infection.
  1. LATENT TB- here TB infection exists but the bacteria is inactive in the body. This type is not contagious but if left untreated then bacteria become active.
  2. ACTIVE TB- it is contagious and can make the person sick. The disease progress week or a year after infection.
  •  SIGN AND SYMPTOMS OF TB: Signs and symptoms include:
  1. Constant coughing for weeks
  2. Blood and mucus in cough
  3. Weight loss
  4. Tiredness
  5. Fever
  6. Chills
  7. Trouble sleeping
  8. Loss of hunger
  9. Pain in the chest while breathing and coughing etc. Tb may also affect other organs like the kidney, brain, or spine, and based on organ affected signs and symptoms vary.
  •  RISK FACTORS: HIV virus that causes AIDS is the major reason for TB because it suppresses the immune system and helps M. Tuberculosis to become active from its inactive stage. A drug-Resistant strain of this bacteria also becoming the major reason for death due to TB. This happens when antibiotic fails to destroy the targeted bacteria and make them resistant to most of the common medications used in TB. Diabetes, kidney problems, cancer, malnutrition, and certain medications are the conditions that weaken the immune system and make the person sensitive to M. Tuberculosis.
  • TREATMENT AND MEDICATIONS: PREVENTING THE SPREAD OF TB: TB disease will take weeks of treatment, till then we can’t stay in isolation, so here are some ways through which we can prevent the spread of disease.
  1. Take medications according to the doctor’s advice.
  2. Cover the mouth while coughing, sneezing, or laughing.
  3. Do not go to work or school until the doctor approves.
  4.  Avoid close contact with anyone. Sleep in a bedroom alone.
  5. Air filter room often to kill the germs.


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