Tuberculosis Flashcards
What percentage of the world population is infected with Tuberculosis?
25%
What is the term used to describe Tuberculosis when it is non-active?
Infection
What is the term used to describe Tuberculosis when it is active?
Disease
What immune cells are the initial responders to Primary Tuberculosis?
Macrophages
Macrophages and T-Cells surrounding Mycobacterium tuberculosis lead to the formation of what?
Granuloma
A unique type of cell death that occurs inside of the granuloma and causes a “cheese-like” appearance.
Caseous Necrosis
A localized area inside the lungs where a granuloma has formed and there is cell death inside causing Caseous Necrosis.
Ghon Focus
What lymph nodes may Tuberculosis spread to resulting in lymphadenopathy?
Hilar Lymph Nodes
When a Ghon Focus and Hilar lymphadenopathy are both present this is called?
Ghon Complex
What is a Ghon Complex consistent with?
Primary TB
Is primary TB usually symptomatic or asymptomatic?
Asymptomatic
What percentage of Primary TB will enter the Latent Stage?
90%
The Ghon Complex will develop fibrocalcifications around it in order to help keep the TB dormant and prevent it from spreading. This fibrocalcification is referred to as what?
Ranke Complex
Is Latent TB contagious?
No
How long can Latent TB remain dormant for?
Years
If a patient with Latent TB became immunocompromised, what might occur?
Re-Activation
When TB is re-activated where does it spread to first?
Apices of the Lungs
When TB spreads to the apices of the lungs, what then develops?
Fibrocaseous Necrosis Lesions (Cavitary)
Necrosis of Lung Parenchyma
- site of Gas Exchange
Reactivation of Tuberculosis is also referred to as what?
Secondary Tuberculosis
What are two characteristics of Secondary Tuberculosis?
Symptomatic
Contagious
Less than 10% of Primary Tuberculosis cases develop into a stage that has the same pathological process as reactivation TB. What is this stage called?
Primary Progressive TB
What are some early symptoms that be associated with active TB?
Malaise
Fever
Weight Loss
Night Sweats (severe)
Hemoptysis
What are some complications of Pulmonary TB?
Pneumothorax
Bronchopneumonia
Pleural Effusion
Hemoptysis
If TB enters the blood stream it can spread to extra-pulmonary sites and then is referred to as what?
Extra-pulmonary TB
Tuberculosis that has spread from the lungs and through the blood and is now affecting multiple organ systems. Formation of multiple millet-sized tuberculous foci may also develop in the lungs.
Miliary TB
Name for when Tuberculosis is in the central nervous system.
Tuberculosis Meningitis
Name for when Tuberculosis is in the spine.
Pott’s Disease
Tuberculosis in the adrenal glands can lead to the inability to produce cortisol and ultimately cause what disease?
Addison’s Disease
Name for when Tuberculosis infects the cervical lymph nodes of the neck.
Scrofula
TB skin test that is read after 48-72 hours.
PPD Test (purified protein derivative)
Mantoux Test
Can the PPD test distinguish active TB from latent TB?
No
What vaccine does not allow for the PPD skin test to be performed properly?
Bacillus Calmette-Guerin (BCG)
What size of induration indicates a positive TB test in a person with no risk factors
Greater than 15mm
What size of induration indicates a positive TB test in a person with medium risk factors?
Greater than 10mm
What size of induration indicates a positive TB test in a person with high risk factors?
Greater than 5mm
What serology test can be performed to diagnose TB and will have results within 24 hours?
Interferon-Gamma Release Assay
- QuantiFERON-TB Gold
Is the Interferon-Gamma Release Assay affected by the BCG vaccine?
Not Usually
What imaging can be performed as an initial approach to a diagnostic evaluation of a patient with suspected TB?
Chest X-Ray
Chest CT
In the diagnosis of TB, how many consecutive morning sputum specimens are advised?
3
What are TB sputum specimens treated with to test for TB?
Ziehl-Neelsan Stain
(Acid-Fast)
Sputum with acid-fast bacilli is indicative of TB, however it does not establish a definitive diagnosis. Why?
Non-Tuberculosis Mycobacteria may be present
What is the definitive diagnosis of TB?
Sputum Culture
How long does it take for a TB sputum culture to provide results?
6 - 8 Weeks
What is another definitive diagnosis of TB?
DNA/RNA Amplification
(takes 1 - 2 days)
Active TB requires a medication regiment for how many months?
6 months
What is the standard treatment for active TB?
Isoniazid
Rifampin
Pyrazinamide (2 months)
Ethambutol (2 months)
What drugs can be used as a monotherapy for Latent Tuberculosis?
Isoniazid (9 months)
Rifampin (4 months)
What two drug therapies can be used to treat Latent Tuberculosis?
Isoniazid + Rifapentine (weekly x3 months)
Isoniazid + Rifampin (daily x3 months)
Type of therapy which requires regular physician visits, who monitor medication intake and look for signs of medication side effects.
Directly Observed Therapy
Type of TB resistant to one of the first line anti-tuberculosis drugs (Isoniazid or Rifampin)
Drug Resistant TB
Type of TB that is resistant to both Isoniazid and Rifampin.
Multi-Drug Resistant TB
Type of TB that is resistant to Isoniazid, Rifampin, fluoroquinolones, and aminoglycosides or capreomycin.
Extremely Drug-Resistant TB
What is the rate of drug resistant TB in the US?
Less than 1.3%
How long should TB patients be hospitalized for upon initial diagnosis and treatment?
2 - 3 weeks
- followed by community isolation
Why is the BCG vaccine not generally recommended in the United States?
Low Prevalence of TB
Interferes with ability to used PPD
