Tuberculosis Flashcards
(47 cards)
What type of disease is Tuberculosis?
A chronic recurrent infectious disease
What is the main cause of tuberculosis?
Mycobacterium tuberculosis bacteria
What type of bacteria is mycobacterium tuberculosis?
Acid-fast bacilli (small rod shaped bacteria)
How is Tuberculosis transmitted?
Inhalation of aerosol droplets containing bacterium
How does Tuberculosis typically present?
- Systemic features
- Low-grade fever
- Anorexia
- Weight loss
- Malaise
- Night sweats,
- Clubbing
- Erythema nodosum
What are the different forms of Tuberculosis
Primary
Secondary/reactivation
Miliary
Where in the body can TB affect?
Anywhere in the body (most commonly the lungs)
In who are the lungs typically affected in someone with Tuberculosis?
- Elderly
- Immunosuppressed
- Malnourished
Which lymph nodes are commonly affected in Tuberculosis?
Painless enlargement of Cervical or supraclavicular lymph nodes
What would you see on a chest x-ray in someone with primary tuberculosis?
Patchy consolidation
Pleural effusions
Hilar lymphadenopathy
What would you see on a chest x-ray in someone with reactivated tuberculosis?
Patchy or nodular consolidation with cavitation (gas filled spaces in the lungs) typically in the upper zones
What would you see on a chest x-ray in someone with Miliary tuberculosis?
“Millet seeds” uniformly distributed throughout the lung fields
What are the two tests for an immune response to TB caused by previous, latent or active TB?
- Mantoux Test
- Interferon-Gamma Release Assays (IGRAs)
What are the main investigations for Tuberculosis?
- Fine-needle aspiration
- AFB staining,
- Culture
What is the name of the stain used to test for mycobacterium tuberculosis?
Zeihl-Neelsen stain
What is a positive result from the Ziehl-Neelsen stain?
The stain turns TB bacteria bright red against a blue background
What is the gold standard investigation for active tuberculosis?
Sputum culture
What is the classic x-ray finding of reactivated tuberculosis?
Upper lobe cavitation
What is primary tubeculosis?
A non-immune host is exposed to M. tuberculosis and develops a small lung lesion called a Ghon focus
What happens during primary tuberculosis in someone who is immunocompetent?
The initial lesion (gohn focus) usually heals by fibrosis
What happens during primary tuberculosis in someone with is immunocompromised?
They may develop disseminated disease (miliary tuberculosis).
What is secondary (post-primary) tuberculosis?
Host becomes immunocompromised the initial infection may become reactivated
Where does reactivation usually occcur in someone with secondary tuberculosis?
In the apex of the lungs
Where can extra-pulmonary infection occur in someone with tuberculosis?
Central nervous system
Vertebral bodies
Cervical lymph nodes
Renal
Gastrointestinal tract
