For each of the following case scenarios, please circle the most appropriate answer (circle only one)
1. A 32 year-old asymptomatic woman who recently emigrated from Vietnam has a 12 mm indurated reaction 72 hours after a tuberculin skin test was placed for employment purposes. Her chest X-ray is unremarkable. She has normal liver function tests. She states she received the BCG vaccine at birth and again at age 20. The next course of action is:
a. Four-drug therapy with isoniazid, rifampin, ethambutol, and pyrazinamide for 2 months, followed by 4 months of isoniazid and rifampin
b. Isoniazid with vitamin B6 for 9 months
c. Sputum sample for acid-fast bacilli and cultures
d. No treatment; the positive tuberculin skin test may be explained by the history of BCG vaccination
2. A 29 year-old homeless man presents to your clinic with a 2-month history of fevers, night sweats, and weight loss. He denies cough or hemoptysis. On physical examination you detect cervical lymphadenopathy, and a chest X-ray reveals normal lung fields but enlarged mediastinal lymph nodes. You suspect extrapulmonary tuberculosis. You place a tuberculin skin test. The next course of action is:
a. Sputum sample for acid-fast bacilli and cultures
b. Cervical lymph node biopsy for acid-fast staining and mycobacterial cultures
c. Blood cultures for mycobacteria
d. Serum early secreted antigen-6 (ESAT-6)
3. One of your co-workers is being relocated to Mali for 2 years. He inquires about tuberculosis prophylaxis. You recommend:
a. BCG vaccination
b. Daily isoniazid during his stay
c. Weekly rifampin during his stay
d. The use of N-95 respiratory masks while in crowded public places
e. No specific prophylaxis
4. A 26 year-old asymptomatic man who recently immigrated from El Salvador is found to have a positive tuberculin skin test. The following are acceptable treatments for latent tuberculosis infection EXCEPT:
a. Daily isoniazid for nine months
b. Daily rifampin for 4 months
c. Daily rifampin and pyrazinamide for 2 months
5. A 5-mm reaction after tuberculin skin test placement is considered positive for all of the following cases EXCEPT:
a. 38 year-old woman with HIV
b. 24 year-old husband of a known TB case
c. 67 year-old man with fibrotic changes in the right upper lobe on chest X-ray
d. 52 year-old woman on immunosuppression for renal transplant
e. 32 year-old nurse working at university student health clinic
6. The lifetime risk of developing active disease in non-HIV-infected patients with latent tuberculosis infection is:
a. 0.1–0.5%
b. 1–2%
c. 5–10%
d. 25–35%
e. 50–75%
7. The annual risk of developing active disease in patients with HIV and latent tuberculosis infection is approximately:
a. 0.1%
b. 1%
c. 10%
d. 25%
e. 50%
8. You have diagnosed a 30 year-old man with pulmonary tuberculosis and have started therapy with a four-drug combination including isoniazid, rifampin, pyrazinamide, and ethambutol. You should advise your patient of the following EXCEPT:
a. To avoid the use of contact lenses
b. To limit the consumption of green leafy vegetables
c. To avoid alcohol consumption
d. To report changes in color vision
e. To report numbness or tingling of the extremities
9. A patient with no prior medical history is diagnosed with pulmonary tuberculosis and you prescribe a daily combination regimen containing isoniazid, rifampin, pyrazinamide, and ethambutol. The patient sees his primary care doctor 3 weeks later for a scheduled office visit, at which time routine chemistry tests reveal a 2-fold elevation of the aspartate aminotransferase (AST) above a normal baseline value. At this point, the patient should:
a. Discontinue isoniazid only
b. Discontinue rifampin only
c. Discontinue rifampin and pyrazinamide
d. Discontinue all anti-TB drugs until AST returns to baseline
e. Continue current regimen and monitor symptoms and transaminases
10. Pyridoxine supplementation (25 mg/day) during treatment of latent tuberculosis infection is recommended for the following patients EXCEPT:
a. 31 year-old pregnant woman
b. 28 year-old man with HIV
c. 74 year-old man with peripheral neuropathy
d. 21 year-old woman with anemia
11. A 67 year-old woman with rheumatoid arthritis and chronic obstructive pulmonary disease presents with a right upper lobe cavitary lesion. Her greatest risk factor for tuberculosis is:
a. Age
b. History of rheumatoid arthritis
c. Prior use of methotrexate
d. Smoking history
e. Prior use of infliximab
The following are TRUE or FALSE statements. Please check the most appropriate answer (check only one)
12. Patients who are AFB smear-negative cannot transmit Mycobacterium tuberculosis.
□ True □ False
13. Patients with extrapulmonary disease are less likely to transmit Mycobacterium tuberculosis than those with pulmonary involvement.
□ True □ False
14. The diagnosis of pulmonary tuberculosis can be reliably excluded on the basis of a negative tuberculin skin test.
□ True □ False
15. The diagnosis of pulmonary tuberculosis can be reliably excluded after 3 sequential sputum samples are negative for acid-fast bacilli (AFB).
□ True □ False
16. The diagnosis of pulmonary tuberculosis can be reliably excluded after a single bronchoscopic alveolar lavage sample is negative for acid-fast bacilli (AFB).
□ True □ False
17. A positive sputum sample using a nucleic acid amplification technique (e.g., the MTB direct test) indicates the diagnosis of tuberculosis.
□ True □ False
18. A negative nucleic acid amplification test (e.g., the MTB direct test) performed on an AFB-negative sputum sample can reliably exclude the diagnosis of tuberculosis.
□ True □ False
19. Of first-line anti-TB agents, rifampin has the greatest potential for drug-drug interactions in patients receiving highly active antiretroviral therapy (HAART).
□ True □ False
20. In HIV-infected patients with CD4 < 100, HAART should be withheld until active tuberculosis has been completely treated.
□ True □ False