Tuberculosis Flashcards
What is the characteristic size range of Mycobacterium tuberculosis?
0.2 to 0.6 x 2-4 micrometers.
Which component of the cell wall contributes to the acid-fastness of Mycobacterium tuberculosis?
Mycolic acid.
What is the primary mode of transmission of tuberculosis?
Inhalation of droplet nuclei.
How long can the infectious particles of tuberculosis remain suspended in the air?
Up to 30 minutes.
Which countries accounted for two-thirds of the global total of tuberculosis cases in 2022?
India, Indonesia, China, the Philippines, Pakistan, Nigeria, Bangladesh, and the Democratic Republic of the Congo.
What are the risk factors associated with tuberculosis?
Poverty, overcrowding, malnutrition, immunosuppression, migration/travel, drug-resistant TB, chronic diseases, cohabitation with active cases, healthcare workers, drug/alcohol abuse.
Which virulence factor of Mycobacterium tuberculosis inhibits the migration of leukocytes and causes chronic granulomas?
Cord factor (trehalose-6,6’-dimycolate).
What type of hypersensitivity can polysaccharides induce in tuberculosis?
Immediate type of hypersensitivity.
How does tuberculosis primarily spread beyond the pulmonary system?
Direct, hematogenous, lymphatic, swallowing of sputum.
What is the characteristic lesion formed in the lungs during primary tuberculosis?
Tubercle.
What is the primary mode of transmission of tuberculosis?
Inhalation of droplet nuclei.
What is the role of cytokines and lymphokines in the pathogenesis of tuberculosis?
They stimulate monocytes and macrophages.
What happens to the tubercle bacilli within the alveolar macrophages?
Replicate within for 2-3 weeks.
What is the consequence of the erosion of granuloma and surrounding tissue in tuberculosis?
Spread through air passages to other parts of the lung.
How does active tuberculosis spread through the lymphatic system?
Through lymphatic vessels.
What is the primary manifestation of primary tuberculosis?
Primary complex with lesion and draining gland.
How does tuberculosis present radiographically in the lungs during primary tuberculosis?
Hilar adenopathy, mid and lower lung field pulmonary infiltrates.
What are the common clinical symptoms of reactivation tuberculosis?
Fever, cough, weight loss, night sweats.
What are the typical radiographic findings in reactivation tuberculosis?
Apical-posterior lung infiltrates, cavities, nodules, effusions, hilar adenopathy.
What percentage of active pulmonary tuberculosis cases have normal chest X-rays?
5%.
What percentage of tuberculosis cases present as extrapulmonary tuberculosis?
15%.
Which organ system is most commonly affected in extrapulmonary tuberculosis?
CNS.
What are the common presentations of tuberculous lymphadenitis?
Chronic, unilateral non-tender lymphadenopathy, especially cervical lymph nodes.
What are the clinical features of tuberculous meningitis?
Malaise, headache, low-grade fever.
What is the prodromal phase of tuberculous meningitis characterized by?
Fever, nuchal rigidity, altered mental status.
What neurological symptoms can occur due to CNS tuberculoma?
Focal neurological symptoms.
What are the features of tuberculous pericarditis?
Features of pericardial effusion or constrictive pericarditis.
What is the most common site of skeletal tuberculosis?
Thoracolumbar spine.
What is the acute, severe form of tuberculosis caused by hematogenous spread?
Miliary tuberculosis.
How is latent tuberculosis infection diagnosed?
Positive result on Tuberculin Skin Test (TST) or Interferon-gamma release assay (IGRA).
What diagnostic methods are used to establish active tuberculosis?
Combination of epidemiological, clinical, radiographic, microbiological, and histopathologic criteria.
Which clinical specimen is used for diagnosing pulmonary tuberculosis?
Spontaneously expectorated sputum.
What type of media is used for culturing Mycobacterium tuberculosis?
Egg-based, agar-based, or liquid-based media.
What are the first-line drugs used in the treatment of tuberculosis?
Isoniazid, Rifampicin, Ethambutol, Pyrazinamide.
Name two second-line drugs used in tuberculosis treatment.
Fluoroquinolones, Thioamides.
What complication of tuberculosis can result in sudden death due to arterial wall erosion?
Massive hemoptysis.
What is the primary preventive measure for tuberculosis?
Early diagnosis, universal drug-susceptibility testing, systematic screening, treatment of all TB cases.
Besides early diagnosis and treatment, what other preventive measures are recommended for tuberculosis control?
Collaborative TB/HIV activities, management of comorbidities, preventive treatment, vaccination, cough hygiene, airborne transmission precautions.
What precautions should be taken in healthcare facilities to prevent the transmission of tuberculosis?
Cough hygiene, airborne transmission precautions.
What are the social determinants of tuberculosis that should be addressed for prevention and control?
Improved nutrition, housing, social protection, poverty alleviation.
