L1 Question 1: What is Bovine Tuberculosis?
Which organism is responsible for bovine tuberculosis?
A) Mycobacterium tuberculosis
B) Mycobacterium bovis
C) Mycobacterium kansasii
D) Mycobacterium avium complex
Answer: B) Mycobacterium bovis
Comment:
Mycobacterium bovis is the primary pathogen responsible for bovine tuberculosis, a zoonotic infection often transmitted through unpasteurized dairy products and close contact with infected cattle.
Incorrect Answers:
- A) Mycobacterium tuberculosis is the most common cause of human tuberculosis but not bovine TB.
- C) Mycobacterium kansasii is a non-tuberculous mycobacterium, not typically causing bovine TB.
- D) Mycobacterium avium complex affects immunocompromised patients but is unrelated to bovine TB.
Reference:
Sharma SK, Mohan A. Extrapulmonary Tuberculosis. Indian J Med Res. 2004;120(4):316-353.
L1 Question 2: Anatomical Involvement
Which anatomical region is most commonly affected in bovine tuberculosis involving the gastrointestinal system?
A) Ascending colon
B) Terminal ileum
C) Cecum
D) Rectum
Answer: C) Cecum
Comment:
The cecum is most commonly involved in bovine tuberculosis due to its rich lymphoid tissue, making it a favorable site for bacterial proliferation.
Incorrect Answers:
- A) The ascending colon is rarely the primary site but can be involved secondarily.
- B) The terminal ileum can be involved but less frequently as a primary site compared to the cecum.
- D) The rectum is not a common site of primary infection.
Reference:
Paustian FF, Fink GH. Gastrointestinal tuberculosis and Mycobacterium bovis infection. AJR Am J Roentgenol. 1985;144(2):285-290.
L1 Question 3: Histopathology
Which histological finding is most characteristic of bovine tuberculosis?
A) Non-caseating granulomas
B) Caseating granulomas
C) Eosinophilic abscesses
D) Lymphoid hyperplasia
Answer: B) Caseating granulomas
Comment:
Bovine tuberculosis is histopathologically characterized by caseating granulomas with central necrosis, epithelioid histiocytes, and Langhans-type multinucleated giant cells.
Incorrect Answers:
- A) Non-caseating granulomas are more typical of sarcoidosis.
- C) Eosinophilic abscesses are seen in parasitic infections rather than TB.
- D) Lymphoid hyperplasia may occur but is not a defining feature.
Reference:
Sharma SK, Mohan A. Miliary tuberculosis and histopathological features. Clin Chest Med. 2019;40(4):705-719.
L1 Question 4: Pathophysiology
What is the primary mechanism of spread for bovine tuberculosis in the abdomen?
A) Direct extension from pulmonary lesions
B) Hematogenous spread
C) Translymphatic spread
D) Inhalation of infectious aerosols
Answer: C) Translymphatic spread
Comment:
Bovine tuberculosis commonly spreads through translymphatic flow from the ileocecal region, involving the peritoneum and omentum.
Incorrect Answers:
- A) Direct spread from pulmonary lesions is uncommon in abdominal TB.
- B) Hematogenous spread can occur but is less common than translymphatic involvement.
- D) Inhalation primarily leads to pulmonary TB rather than abdominal involvement.
Reference:
Burrill J et al. Radiologic patterns of extrapulmonary tuberculosis. Radiographics. 2007;27(5):1255-1273.
L1 Question 5: Radiology (CT Characteristics)
Which of the following findings is most specific for bovine TB on abdominal CT? (Multiple answers can be correct)
A) Ascites with peritoneal enhancement
B) Nodular omental caking
C) Calcified granulomas
D) Thickened ileocecal valve
Answer: A, B, D
Comment:
CT findings of bovine TB commonly include ascites with peritoneal enhancement, nodular omental caking, and ileocecal valve thickening, often with pericolonic fat stranding.
Incorrect Answers:
- C) Calcified granulomas are more typical of chronic or healed TB rather than active infection.
Reference:
Sahn SA, Sharma SK. Abdominal tuberculosis: Imaging findings and diagnostic challenges. AJR Am J Roentgenol. 2011;196(2):325-330.
L2 (Advanced)
L2 Question 6: Clinical Presentation
Which of the following symptoms is most consistent with abdominal bovine tuberculosis?
A) Hemoptysis
B) Chronic diarrhea and weight loss
C) Jaundice
D) Hematuria
Answer: B) Chronic diarrhea and weight loss
Comment:
Abdominal TB often presents with chronic diarrhea, abdominal pain, and weight loss due to cecal involvement and secondary malabsorption.
Incorrect Answers:
- A) Hemoptysis is more typical of pulmonary TB.
- C) Jaundice can occur in hepatic TB but is less common.
- D) Hematuria is more typical of genitourinary TB.
Reference:
Sharma SK, Mohan A. Extra-pulmonary tuberculosis. Indian J Med Res. 2004;120(4):316-353.
L2 Question 7: Imaging
What is the typical appearance of omental involvement in bovine tuberculosis on CT?
A) Smooth omental thickening without nodularity
B) Nodular omental caking with ascites
C) Isolated peritoneal effusion
D) Calcified lymph nodes without ascites
Answer: B) Nodular omental caking with ascites
Comment:
Nodular omental caking with ascites and peritoneal thickening is a hallmark of disseminated abdominal TB and often involves translymphatic spread.
Incorrect Answers:
- A) Smooth omental thickening is more typical of peritoneal carcinomatosis.
- C) Isolated effusion without omental involvement is non-specific.
- D) Calcified lymph nodes without ascites is less common in active TB.
Reference:
Maliwan N et al. Radiologic features of tuberculous peritonitis. Radiographics. 2018;38(3):761-773.
L2 Question 8: Differential Diagnosis
Which of the following conditions can mimic bovine TB with omental caking? (Multiple answers can be correct)
A) Peritoneal carcinomatosis
B) Primary peritoneal mesothelioma
C) Pseudomyxoma peritonei
D) Crohn?s disease
Answer: A, B, C
Comment:
Omental caking can be seen in peritoneal carcinomatosis, primary mesothelioma, and pseudomyxoma peritonei, though TB often presents with more uniform thickening.
Incorrect Answer:
- D) Crohn?s disease is typically associated with mural thickening, not omental nodularity.
Reference:
Sahn SA et al. Radiologic features of tuberculous peritonitis. AJR Am J Roentgenol. 2011;196(2):325-330.
L2 Question 9: Management
What is the standard treatment for bovine tuberculosis?
A) 6 months of first-line anti-TB therapy
B) Surgery without medication
C) 12 months of therapy with second-line agents
D) No treatment required
Answer: A) 6 months of first-line anti-TB therapy
Comment:
First-line anti-TB therapy (INH, RIF, PZA, EMB) for 6 months is the standard treatment for drug-susceptible bovine TB.
Incorrect Answers:
- B) Surgery is reserved for complications like obstruction.
- C) 12 months is reserved for resistant cases.
- D) Treatment is always required for active cases.
Reference:
Nahid P et al. ATS/CDC/IDSA clinical practice guidelines. Clin Infect Dis. 2016;63(7):853-867.
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