### Date : 2024-06-19 18:53 ### Topic : Tuberculosis - The Silent Invader #medicine #pulmonology ---- ### Tuberculosis (TB) Overview **Tuberculosis (TB)** is an infectious disease caused by the bacterium **Mycobacterium tuberculosis**. It primarily affects the lungs (pulmonary TB) but can also affect other parts of the body (extrapulmonary TB). TB is a major global health issue and can be fatal if not properly treated. ### Pathophysiology TB is transmitted through airborne particles when a person with active pulmonary TB coughs, sneezes, or speaks. When inhaled, the bacteria can reach the alveoli of the lungs, where they are ingested by macrophages. The bacteria can either be contained by the immune system, leading to latent TB, or proliferate, leading to active TB disease. ### Types of Tuberculosis 1. **Latent TB Infection (LTBI):** - The bacteria remain in the body in an inactive state and cause no symptoms. - Individuals are not contagious but can develop active TB if the immune system weakens. 2. **Active TB Disease:** - The bacteria are active and cause symptoms. - Individuals are contagious and can spread the disease to others. ### Clinical Features **Pulmonary TB:** - **Persistent Cough:** Lasting more than three weeks, often with sputum production. - **Hemoptysis:** Coughing up blood. - **Chest Pain:** Pain with breathing or coughing. - **Fever and Night Sweats:** Common systemic symptoms. - **Weight Loss and Fatigue:** Significant weight loss and chronic fatigue. **Extrapulmonary TB:** - **Lymph Nodes:** Swelling, often in the neck (scrofula). - **Pleura:** Pleural effusion (fluid in the pleural space). - **Central Nervous System:** Tuberculous meningitis. - **Bones and Joints:** [[Spinal TB (Pott's disease)]]. - **Genitourinary System:** TB affecting the kidneys, bladder, or reproductive organs. ### Diagnosis Diagnosis of TB involves a combination of clinical evaluation, imaging, microbiological tests, and sometimes histopathological examination: 1. **Clinical Evaluation:** - Assessment of symptoms and medical history, including any exposure to TB. 2. **Tuberculin Skin Test (TST) or Mantoux Test:** - Injection of purified protein derivative (PPD) into the skin and reading the reaction 48-72 hours later. 3. **Interferon-Gamma Release Assays (IGRAs):** - Blood tests (e.g., QuantiFERON-TB Gold) that measure the immune response to TB bacteria. 4. **Imaging Studies:** - **Chest X-ray:** To identify lung abnormalities consistent with TB. - **CT Scan:** More detailed imaging if needed. 5. **Microbiological Tests:** - **Sputum Smear Microscopy:** Detection of acid-fast bacilli (AFB). - **Sputum Culture:** Growing the bacteria to confirm TB and test for drug resistance. - **Nucleic Acid Amplification Tests (NAATs):** Rapid detection of TB bacteria and resistance to rifampicin. 6. **Histopathology:** - Biopsy of affected tissues, showing granulomas with caseous necrosis. Sure! Here's an example case of a patient with tuberculosis: ### Case Study: Tuberculosis #### Patient Information: - **Name:** Jee Hoon Ju - **Age:** 45 years old - **Gender:** Male - **Occupation:** Construction worker - **Location:** Urban area with moderate TB prevalence #### Medical History: - **Past Medical History:** - No significant past medical history - No known allergies - **Social History:** - Smoker (20 pack-years) - Occasional alcohol use - Lives in a crowded apartment with his family - No history of travel to TB-endemic areas - **Family History:** - No family history of TB or other chronic diseases #### Presenting Complaints: - **Chief Complaint:** Persistent cough for over three weeks - **Associated Symptoms:** - Coughing up blood (hemoptysis) - Chest pain - Unintentional weight loss (10 kg over the past two months) - Fatigue - Night sweats - Fever (low-grade, intermittent) #### Physical Examination: - **General Appearance:** - Appears chronically ill and fatigued - Mildly underweight - **Vital Signs:** - Temperature: 38°C (100.4°F) - Pulse: 92 beats per minute - Respiratory Rate: 20 breaths per minute - Blood Pressure: 120/80 mmHg - **Respiratory Examination:** - Dullness to percussion in the upper right lung - Crackles and wheezes heard in the upper right lung field - Decreased breath sounds in the same area #### Initial Investigations: - **Chest X-ray:** - Findings: Cavitary lesions in the upper lobe of the right lung - **Sputum Analysis:** - Acid-fast bacilli (AFB) smear: Positive - Sputum culture: Pending #### Diagnosis: Based on the patient's symptoms, physical examination, chest X-ray findings, and positive AFB smear, a diagnosis of pulmonary tuberculosis (TB) is made. #### Treatment Plan: 1. **Initiation of Anti-TB Therapy:** - **Isoniazid (INH):** 300 mg daily - **Rifampicin (RIF):** 600 mg daily - **Ethambutol (EMB):** 1200 mg daily - **Pyrazinamide (PZA):** 2000 mg daily - Duration: Initial phase for 2 months, followed by a continuation phase of INH and RIF for 4 months 2. **Directly Observed Therapy (DOT):** - To ensure adherence, the patient will be enrolled in a DOT program where a healthcare provider will supervise his medication intake. 3. **Supportive Care:** - Nutritional support to address weight loss and malnutrition - Counseling on smoking cessation - Education on the importance of medication adherence and infection control measures to prevent transmission to family members 4. **Follow-Up:** - Monthly follow-ups to monitor treatment response and side effects - Repeat sputum analysis after 2 months of treatment to assess for bacterial clearance 5. **Public Health Measures:** - Contact tracing to identify and screen close contacts for TB infection - Notify local public health authorities for appropriate TB surveillance and control measures #### Outcome: The patient responds well to the treatment with gradual resolution of symptoms. Follow-up sputum cultures after 2 months show no growth of *Mycobacterium tuberculosis*. The patient completes the full 6-month course of therapy with no significant side effects and is declared cured of TB. Public health follow-up ensures that no secondary cases arise from his close contacts. ### Conclusion Tuberculosis is a serious infectious disease that requires timely diagnosis and effective management to prevent complications and spread. Understanding the clinical features, diagnostic methods, and treatment options is essential for healthcare providers to manage and control TB effectively. Regular follow-up and adherence to therapy are crucial for ensuring successful outcomes.