MDR-TB Definition Explained
Multidrug-resistant tuberculosis (MDR-TB) is a specific form of tuberculosis (TB) characterized by resistance to the most effective anti-TB medications.
Identifying MDR-TB Resistance
The standard definition of MDR-TB requires the bacteria to be resistant to at least:
- Isoniazid (INH)
- Rifampicin (RIF)
These two drugs are the cornerstones of standard first-line TB treatment. Resistance to both signifies MDR-TB.
Analyzing the Options
Based on the definition:
- Option 1 is incorrect because MDR-TB is defined by resistance to specific key drugs, not just a minimum number.
- Option 2 is incorrect as it lists resistance to three drugs but not necessarily the defining pair (INH and RIF).
- Option 3 is correct because it accurately states the minimum requirement for MDR-TB: resistance to both Isoniazid and Rifampicin.
- Option 4 is incorrect as it lists resistance to Rifampicin but pairs it with Streptomycin instead of the defining drug, Isoniazid.
Therefore, the presence of resistance to at least Isoniazid and Rifampicin defines multidrug-resistant tuberculosis.
Important Questions from Inflammation
A 24 year old man presents with acute onset shortness of breath with precordial chest pain. ECG reveals ST elevation with upward concavity and PR segment depression in lead V2 to V6 and reciprocal changes in lead aVR. The most likely diagnosis is
- Systemic Inflammatory Response Syndrome (SIRS) is characterized by all of the following EXCEPT:
- Which one of the following statements is correct?
- Aortic stenosis is associated with:
- Exacerbations of bronchial asthma that occur with little or no warning are called:
