Tuberculosis Flashcards
What is tuberculosis?
Infectious diseases caused by Mycobacterium tuberculosis typically affecting the lungs
What are the risk factors of tuberculosis?
Immunosuppression (i.e. HIV) Drug abuse Alcoholism Malnutrition Diabetes mellitus
What is the pathophysiology of tuberculosis?
Alveolar macrophages (CD14+) phagocytose the TB bacteria but cannot eliminate them due to cord factor inhibiting fusion of lysosome with phagosome. TB contained in macrophages for caseating granulomas
What are the clinical features of tuberculosis?
(Systemic) fever, weight loss, night sweats, fatigue, lymphadenopathy
(Pulmonary) Dyspnea, productive cough (possibly hemoptysis) lasting > 3 weeks
What organs are affected by pulmonary tuberculosis and its clinical features?
Central nervous system (CNS), heart, urogenital and gastrointestinal tracts, and the skin
(Urogenital) dysuria, flank pain, hematuria, low-grade fever. Sterile leukocytosis
What is miliary tuberculosis?
Massive lymphohematogenous spread of Mycobacterium tuberculosis bacilli from a pulmonary or extrapulmonary focus with multiple organ involvement and very small granuloma lesions (1–2 mm)
How is tuberculosis diagnosed?
(Chest x-ray) Primary: Ghon complex
Secondary: Cavitation in upper lobe
(Sputum microscopy with acid-fast stain)
(Sputum culture)
How is latent tuberculosis screened?
(Mantoux test) 0.1 ml of 1:1,000 purified protein derivative (PPD) injected intradermally to look for hypersensitivity reaction days later
(Interferon-γ release assay) ELISA test that measures the level of interferon-γ expressed by T cells after coming into contact with synthetic TB-specific peptides
What is the treatment for active tuberculosis?
(Initial-2 months) Rifampicin Isoniazid Pyrazinamide Ethambutol (Continuation-4 months) Rifampicin Isoniazid
What is the treatment for latent tuberculosis?
3 months of isoniazid (with pyridoxine) and rifampicin OR 6 months of isoniazid (with pyridoxine)
