7.1 Tuberculosis Flashcards
What is the cause of TB in humans?
Mycobacterium tuberculosis
Why can a Gram stain not be done on M. tuberculosis?
What is done instead?
Cell wall is enhanced by glycolipids, fatty acid chains and complex waxes. This is to survive living inside a macrophage.
Acid fast test done instead.
How is TB transmitted?
Respiratory droplets
What happens once a patient is infected with TB?
Invades macrophages
Enters regional lymph nodes
Forms primary complex
Progress to active disease OR Initially contain disease
What is post primary TB?
Reactivation of latent disease or re-infection of TB secondary to an initial infection >5 years previously.
What are the risks of reactivating latent TB infections?
HIV Immunosuppression Organ transplant Diabetes mellitus Severe kidney disease Substance abuse
What is the pathology of TB?
Found in the upper lobes of the lung Langhans Giant Cells Granulomas Lymphocytes Caseating granulomata
What are some risk factors of catching TB?
HIV Non-UK born Homeless Drug user Young adult Close contact with a TB sufferer
What sites of the body can TB affect?
Pulmonary Pleura Brain Kidneys Lymph nodes Larynx
How is TB treated?
RHZE Rifampicin Isoniazid Pyrazinamide Ethambutol
How can TB be prevented?
BCG vaccine
Any case notified to Public Health to monitor disease spread
What is miliary TB?
TB infection which has entered the blood and infected many areas of the body.
What tests can be done to measure the body’s immune response to TB?
TST
IGRA
What are the symptoms of pulmonary TB?
Crackles Fever Night sweats Tiredness Cough Haemoptysis
What investigations can be done to confirm TB?
Chest xray
Bronchoscopy
Test sputum samples
Full blood count
