TB Flashcards
What is Tuberculosis (TB)?
A disease caused by Mycobacterium tuberculosis that typically affects the lungs.
What causes Tuberculosis?
Mycobacterium tuberculosis (aerobic, acid-fast bacilli).
How is Tuberculosis transmitted?
Airborne droplets.
List some risk factors for Tuberculosis.
- Immunosuppression (HIV, immunosuppressant drugs, TNFα inhibitors)
- Diabetes mellitus
- Stage 5 chronic kidney disease
- Previous lung disease
- Smoking, drug abuse, alcohol
- Malnutrition, poverty
- Certain living conditions (prisons, homeless shelters)
- Occupational exposure (hospitals)
Define Pulmonary TB.
TB that affects the lung parenchyma.
Define Extrapulmonary TB.
TB in other organs such as lymph nodes, abdomen, genitourinary tract, skin, joints, bones, and meninges.
What is Miliary TB?
A disseminated form of TB that can affect multiple organs simultaneously.
What does a Tuberculin positive result indicate?
Exposure to Mycobacterium tuberculosis or vaccination (BCG vaccine) but does NOT indicate active disease.
What is a smear positive result in TB diagnosis?
Acid-fast bacilli detected in sputum smear microscopy.
What is the difference between smear negative and culture negative results?
Smear negative means no acid-fast bacilli detected in sputum but positively grows in culture; culture negative means no acid-fast bacilli in sputum or culture.
List the history of treatment classifications for TB.
- New
- Relapse
- Treatment after failure
- Treatment after loss to follow-up
- Chronic case
What are the severity classifications of TB?
- Drug-sensitive TB (DS-TB)
- Multidrug-resistant TB (MDR-TB)
- Extensively drug-resistant TB (XDR-TB)
What characterizes latent TB infection?
Asymptomatic and non-contagious.
What are the constitutional symptoms of active TB infection?
- Fever (gradual/low-grade)
- Night sweats
- Weight loss
- Anorexia
- Malaise
What symptoms are associated with pulmonary TB?
- Dyspnea
- Cough (initially dry then productive)
- Hemoptysis
- Chest pain
What signs are indicative of pulmonary TB?
- Crackles
- Bronchial breath sounds
What symptoms may occur with extrapulmonary TB?
Symptoms based on organ involvement, e.g. enlarged lymph nodes, pleuritic chest pain, skeletal pain, urinary symptoms, abdominal swelling/pain, headache.
What is the first-line test for screening latent or active TB disease?
Tuberculin Skin Test (TST) or Mantoux test.
What do Interferon Gamma Release Assays (IGRAs) measure?
Immune response to TB in blood, unaffected by previous BCG vaccine.
What findings on a chest X-ray suggest TB?
Upper lobe infiltrates, cavitations, miliary pattern.
What is the gold standard for TB diagnosis?
Sputum culture.
But can take up to 6 weeks!!
What treatment is given for latent TB?
Isoniazid (9 months)
OR
Rifampin (4 months).
What is the active TB treatment?
2 phase:
(1) 2 months of Rifampin + Isoniazid + Pyrazinamide + Ethambutol. (RIPE)
(2) 4 months of Rifampin + Isoniazid
What is monitored during TB treatment?
Sputum samples monthly until 2 consecutive negative results.
