TB

Overview Of TB

Tuberculosis (TB) is a contagious bacterial infection caused by *Mycobacterium tuberculosis*, primarily affecting the lungs but capable of spreading to other organs such as the kidneys, spine, and brain. It is transmitted through airborne particles when an infected person coughs, sneezes, or speaks. TB remains one of the world's deadliest infectious diseases, with an estimated 10.8 million people falling ill and 1.25 million dying from the disease in 2023, including 161,000 people with HIV. Despite being preventable and curable, TB disproportionately affects low- and middle-income countries, with over 80% of cases and deaths occurring in these regions.

Causes of TB

• TB is caused by the bacterium *Mycobacterium tuberculosis*. The disease spreads through the air when an infected person releases bacteria-containing droplets. Factors such as weakened immune systems (e.g., due to HIV, diabetes, or malnutrition), overcrowded living conditions, and tobacco use increase the risk of infection and progression to active disease.

Risk Factors of TB

• Risk factors for TB include:
• Weakened Immune System: HIV/AIDS, diabetes, or use of immunosuppressive drugs.
• Close Contact: Living or working with someone who has active TB.
• Geographic Location: Residing in or traveling to regions with high TB prevalence, such as parts of Africa, Asia, and Eastern Europe.
• Substance Abuse: Alcoholism or drug use.
• Poor Living Conditions: Overcrowded or unsanitary environments.

Prevention of TB

• Preventive measures include:
• Vaccination: The BCG vaccine is used in high-risk countries to prevent severe forms of TB in children.
• Infection Control: Proper ventilation, wearing masks, and isolating infectious patients.
• Latent TB Treatment: Administering preventive therapy to individuals with latent TB to reduce the risk of progression to active disease.

Prognosis of TB

• With proper treatment, most TB cases are curable. However, untreated or inadequately treated TB can be fatal. Drug-resistant TB poses a significant challenge, with lower cure rates and higher mortality. Early diagnosis and adherence to treatment are key to improving outcomes.

Complications of TB

• Complications of TB include:
• Lung Damage: Chronic scarring and reduced lung function.
• Disseminated TB: Spread to multiple organs, leading to severe systemic illness.
• Meningitis: Inflammation of the brain and spinal cord membranes.
• Drug Resistance: Emergence of multidrug-resistant (MDR-TB) or extensively drug-resistant (XDR-TB) strains.

Related Diseases of TB

• Related conditions include:
• HIV/AIDS: A major risk factor for TB progression.
• Multidrug-Resistant TB (MDR-TB): TB strains resistant to first-line drugs.
• Extensively Drug-Resistant TB (XDR-TB): TB strains resistant to second-line drugs.
• Pneumonia: Often co-occurs with or mimics TB.
• Chronic Obstructive Pulmonary Disease (COPD): Can be exacerbated by TB.

Treatment of TB

TB is treated with a combination of antibiotics over several months. The standard regimen for drug-susceptible TB includes isoniazid, rifampin, pyrazinamide, and ethambutol for two months, followed by isoniazid and rifampin for four months. Drug-resistant TB requires longer and more complex treatment, often involving second-line drugs. Adherence to treatment is critical to prevent relapse and drug resistance.