Tuberculosis: Definition, Causes, Symptoms, and Treatment

Definition and Causes

• TB (Tuberculosis) is a bacterial infection caused by Mycobacterium tuberculosis
• Primarily affects the lungs, but can also affect other parts of the body

Transmission

• Spread through the air when an infected person talks, coughs, or sneezes
• Can also be spread through infected milk or improperly pasteurized dairy products
• Not spread through casual contact, touching, or sharing food and drinks

Symptoms

• Coughing for three or more weeks
• Chest pain or coughing up blood
• Fatigue, weight loss, and loss of appetite
• Chills, fever, and night sweats
• Coughing up mucus or phlegm

Types of TB

• Latent TB infection: The bacteria remain dormant in the body, but the person is not infectious
• Active TB disease: The bacteria are multiplying and the person is infectious
• Drug-resistant TB: The bacteria are resistant to one or more anti-TB drugs
• Multidrug-resistant TB (MDR-TB): Resistant to at least isoniazid and rifampicin
• Extensively drug-resistant TB (XDR-TB): Resistant to isoniazid, rifampicin, fluoroquinolones, and at least one injectable second-line drug

Diagnosis

• Tuberculin skin test (Mantoux test): A small amount of TB antigen is injected under the skin to test for a reaction
• Interferon-gamma release assay (IGRA): A blood test that measures the immune system's response to TB bacteria
• Chest X-rays and CT scans: Used to examine the lungs for signs of TB
• Sputum smear microscopy: Examines a sample of mucus from the lungs for TB bacteria

Treatment

• Antibiotics: Isoniazid, rifampicin, pyrazinamide, and ethambutol are commonly used
• Directly Observed Therapy (DOT): A healthcare worker observes the patient taking their medication
• Treatment duration: Typically 6-9 months for latent TB infection and 12-24 months for active TB disease