1. AntiTB drug that has bacteriociddal and sterilizing effect on tissue is:
A) Rifampicin
B) INH
C) Ethambutol
D) Pyrazinamide
2. Following type of pulmonary TB is most likely to be associated with AFB sputum positivity:
A) Primary complex
B) Fifronodular
C) Cavitary
D) Pleural effusion
3. Following antiTB drug is associated with major visual side effects:
A) INH
B) Rifampicin
C) Ethambutol
D) Pyrazinamide
4. Empyema necessitans is:
A) Common manifestation of post primary TB:
B) Extension of empyema to the thoracic cage
C) Empyema associated with pneumonia
D) Part of Primary complex
5. Fibro-cavitary lung lesion on x-ray is a feature of:
A) Primary TB
B) Post primary TB
C) Metastatic lung disease
D) Lung abscess
6. Miliary TB on CT scan has:
A) Peribronchial distribution of lesions
B) Lesions randomly distributed measuring 1-2 mm
C) Small granulomas with satellite lesions
D) Small nodules with caseation
7. Gohn’s focus is usually:
A) Subpleural
B) Peribronchial
C) Apical
D) In lyphnode
8. Mantoux test :
A) Is carried out by intradermal inoculation of live attenuated bacilli.
B) Positivity indicates prior exposure of the individual to M. Tuberculosis.
C) Positivity indicates good immunity against TB
D) Is a measure of individuals humoral immunity
9. Anti TB drugs with maximum CNS penetration are:
A) INH and Rifampicin
B) INH and Streptomicin
C) INH and Ethambutol
D) INH and Pyrazinamide
10. When TB is associated with AIDS:
A) Mantaox reading is affected
B) CSF parameters are affected
C) First line management is affected
D) TB is caused by atypical mycobacteria
Answers and discussions:
Answer: 1-A
Rifampicin is a bacteriocidal antiTB drug that kills both multiplying and dormant bacteria hence it sterilizes the tissue. INH is effective against multiplying bacilli. Ethambutol in low dose is bacteriostatic and in high dosages, is bacteriocidal. Pirazinamide is a mild bacteriocidal drug but has a property of killing bacilli in acidic environment such as, in macrophages and areas of acute inflammation. It can cross blood brain barrier in good concentration.
Answer: 2-C
Cavities represent necrosis of tissue resulting in communication of the infected material with the airways. The bacteria are thus discharged in the bronchial tree from where they can be coughed out with sputum. The infected material can cause tubercular bronchopneumonia in host by spread to other parts of lungs or gastro-intestinal tuberculosis by means of swallowed secretions. The risk of spread to other individual is very high with cavitary tuberculosis.
Answer: 3-C
Hepatotoxicity is the most common side effect of antiTB treatment. INH, rifampicin and pyrazinamide ate hepatotoxic. INH may cause sensory neuropathy. Rifampicin may cause itching in first two weeks and may cause thrombocytopenia. Ethambutol can cause retrobulbar neuritis which, in some cases, may be irreversible.
Answer: 4-B
Empyema necessitance is an uncommon manifestation of TB when TB empyema extends to the thoracic cage.
Answer: 5-B
Primary complex is a small area of consolidation in subpleural parenchyma. Post primary TB occurs in immunocompetent hosts and causes caseating granulomas. The caseous material gets drained out through bronchi resulting in small cavities surrounded by fibrosis. Lung abscess is a thick walled cavity on X-ray.
Answer: 6-B
Miliary TB is caused by hematogenous spread of TB bacilli and has characteristic appearance on CT scan of chest with randomly distributed lesions measuring 1-2 mm.
Answer: 7-A
Answer: 8-B
Mantoux test is carried out by intradernmal injection of purified protein derivative extracted from tubercular bacilli culture. It is a sterile solution and does not contain live bacteria. Positive mantoux test indicates prior exposure to TB. It is a measure of cell mediated immunity and not of humoral immunity. Positive test does not necessarily mean good immunity.
Answer: 9-D
INH and pyrazinamide have 100% CNS penetration and are important in treatment of TB meningitis.
Answer: 10- A
In an immunodeficient person such as, a case of AIDS, cell mediated immunity is deficient. Mantaox test detects cell mediated response of an individual to tuberculin antigen. Hence the test will show lower induration or less positivity. Rest of the parameters are not affected.
