Introduction
Pulmonary tuberculosis (TB) is a serious infectious disease that primarily affects the lungs but can spread to other organs. It is caused by the bacterium Mycobacterium tuberculosis and is transmitted through airborne droplets when an infected person coughs or sneezes. TB remains a significant global health challenge, especially in developing countries. This article provides a detailed overview of pulmonary tuberculosis, including its causes, symptoms, diagnosis, and treatment options.
Causes and Risk Factors
Pulmonary tuberculosis is caused by Mycobacterium tuberculosis, a slow-growing bacterium that primarily targets the lungs. The disease is highly contagious and spreads through inhaling infected droplets from an infected person. Several factors increase the risk of contracting TB, including:
Weakened Immune System: People with HIV/AIDS, diabetes, or undergoing chemotherapy are at higher risk.
Malnutrition: Poor nutrition weakens the immune system, making it easier for TB to develop.
Close Contact with Infected Individuals: Living or working in crowded places increases exposure.
Substance Abuse: Excessive alcohol consumption and drug use weaken the immune response.
Smoking: Increases the risk of developing active TB.
Previous TB Infection: Latent TB can reactivate when immunity is compromised.
Symptoms of Pulmonary Tuberculosis
TB symptoms vary depending on the severity of the infection. The disease progresses slowly, and some people may not notice symptoms for months. Common symptoms include:
Primary Symptoms:
Persistent cough lasting more than three weeks
Coughing up blood (hemoptysis)
Chest pain or discomfort
Shortness of breath
General Symptoms:
Fever and night sweats
Fatigue and weakness
Loss of appetite and unintended weight loss
Chills and body aches
If left untreated, TB can spread to other organs, leading to severe complications such as meningitis, bone infections, and kidney damage.
Diagnosis of Pulmonary Tuberculosis
Early diagnosis of TB is crucial for effective treatment and preventing its spread. Several diagnostic tests are used to confirm the presence of TB:
Tuberculin Skin Test (TST) or Mantoux Test: A small amount of tuberculin is injected under the skin. A raised, red bump indicates TB exposure.
Interferon-Gamma Release Assays (IGRAs): Blood tests that detect immune response to Mycobacterium tuberculosis.
Chest X-ray: Identifies lung abnormalities, including cavities and nodules.
Sputum Microscopy and Culture: Examines lung secretions for TB bacteria.
GeneXpert MTB/RIF Test: A rapid molecular test that detects TB and resistance to rifampin (an antibiotic used to treat TB).
CT Scan: Provides detailed imaging to assess lung damage.
Treatment of Pulmonary Tuberculosis
TB treatment involves a long-term course of antibiotics to eliminate the bacteria and prevent drug resistance. The standard treatment plan is known as the Directly Observed Treatment, Short-course (DOTS) strategy.
1. First-Line Medications (Standard Treatment for Drug-Sensitive TB):
Isoniazid (INH): Kills actively growing bacteria.
Rifampin (RIF): Prevents bacterial replication.
Ethambutol (EMB): Prevents bacterial cell wall formation.
Pyrazinamide (PZA): Effective in acidic environments, such as infected lung tissue.
The treatment duration typically lasts six months and is divided into two phases:
Intensive Phase (First 2 Months): All four drugs are taken daily.
Continuation Phase (Next 4 Months): Isoniazid and rifampin are taken daily or three times a week.
2. Treatment for Drug-Resistant TB (MDR-TB and XDR-TB)
In cases of multi-drug-resistant TB (MDR-TB) or extensively drug-resistant TB (XDR-TB), alternative medications are used:
Bedaquiline
Linezolid
Delamanid
Fluoroquinolones (Levofloxacin, Moxifloxacin)
Injectable antibiotics (Amikacin, Capreomycin)
Treatment for drug-resistant TB can last 18 to 24 months and requires close monitoring.
Preventing Tuberculosis
Prevention plays a crucial role in controlling TB spread. Key preventive measures include:
BCG Vaccine: Bacillus Calmette-Guérin (BCG) is given to infants in high-risk countries.
Early Detection and Treatment: Prompt diagnosis and completing the full course of antibiotics prevent transmission.
Improving Ventilation: Good airflow in crowded places reduces airborne spread.
Wearing Masks: Infected individuals should wear masks to prevent spreading bacteria.
Healthy Lifestyle: A strong immune system lowers the risk of TB infection.
Complications of Tuberculosis
If untreated, TB can cause severe complications, including:
Pulmonary Fibrosis: Permanent lung scarring that reduces breathing capacity.
Pleural Effusion: Fluid buildup around the lungs, causing breathing difficulties.
Disseminated TB (Miliary TB): TB bacteria spread throughout the body via the bloodstream.
Meningitis: TB infection of the brain and spinal cord.
Liver and Kidney Damage: Due to prolonged TB infection.
Prognosis
With early detection and proper treatment, TB is curable. However, untreated TB can be fatal. Patients must complete their prescribed medications to prevent relapse and drug resistance. Public health initiatives continue to focus on TB elimination through vaccination, improved healthcare access, and awareness campaigns.
Conclusion
Pulmonary tuberculosis is a highly infectious disease that remains a global health concern. Early diagnosis, appropriate treatment, and preventive measures are essential in controlling TB. If you experience prolonged cough, weight loss, or fever, seek medical attention promptly. By raising awareness and ensuring proper healthcare access, TB can be effectively managed and prevented.