Internal Medicine Exam Infectious Disease Management 4 — Questions and Answers
Question 1: A 50-year-old immunocompromised patient develops fever, pleuritic chest pain, and a pulmonary infiltrate with a halo sign on CT chest. Galactomannan is positive. What is first-line treatment?
- Amphotericin B deoxycholate
- Voriconazole (Correct answer)
- Fluconazole
- Caspofungin monotherapy
Correct answer: Voriconazole
Voriconazole is first-line therapy for invasive pulmonary aspergillosis, demonstrating superior survival over amphotericin B in landmark trials.
Question 2: A patient with severe sepsis is started on empiric broad-spectrum antibiotics. Blood cultures later grow Pseudomonas aeruginosa sensitive to piperacillin-tazobactam. At 72 hours the patient is clinically improving. What is the appropriate antibiotic de-escalation?
- Continue broad-spectrum regimen for full 14-day course
- Narrow to piperacillin-tazobactam alone (Correct answer)
- Discontinue all antibiotics
- Switch to oral fluoroquinolone regardless of susceptibilities
Correct answer: Narrow to piperacillin-tazobactam alone
Antibiotic stewardship mandates de-escalation to the narrowest effective agent once culture and sensitivity data are available, reducing resistance and adverse effects.
Question 3: A 28-year-old pregnant woman at 36 weeks is found to have group B Streptococcus (GBS) on vaginal-rectal screening. She is penicillin-allergic with a history of urticaria only (not anaphylaxis). What is the appropriate intrapartum prophylaxis?
- Cefazolin IV (Correct answer)
- Clindamycin IV (if susceptible)
- Vancomycin IV
- No prophylaxis needed
Correct answer: Cefazolin IV
For GBS-positive patients with low-risk penicillin allergy (urticaria, not anaphylaxis), cefazolin is safe and preferred for intrapartum prophylaxis.
Question 4: A 60-year-old man with diabetes develops unilateral facial pain, periorbital swelling, and black eschar on the nasal turbinate. CT shows bony destruction of the sinuses. What is the most appropriate treatment?
- IV voriconazole plus surgical debridement
- Liposomal amphotericin B plus urgent surgical debridement (Correct answer)
- Oral itraconazole and close outpatient follow-up
- Systemic corticosteroids to reduce inflammation
Correct answer: Liposomal amphotericin B plus urgent surgical debridement
Rhinocerebral mucormycosis requires immediate liposomal amphotericin B combined with aggressive surgical debridement; delay is associated with rapid mortality.
Question 5: A hospitalized patient develops fever 5 days after a central venous catheter insertion. Blood cultures from the line and periphery both grow Candida albicans. What is the FIRST management step?
- Start fluconazole and leave the catheter in place
- Remove the central venous catheter and start echinocandin therapy (Correct answer)
- Obtain repeat cultures and wait for sensitivity results
- Start topical antifungal and reassess in 24 hours
Correct answer: Remove the central venous catheter and start echinocandin therapy
Candidemia requires prompt catheter removal (source control) and initiation of an echinocandin, which is preferred over fluconazole for empiric treatment pending species identification.
Question 6: A 55-year-old man with cirrhosis presents after eating raw oysters with rapidly progressive bullous skin lesions and septic shock. Blood cultures are pending. What pathogen is most likely?
- Vibrio vulnificus (Correct answer)
- Listeria monocytogenes
- Aeromonas hydrophila
- Clostridium perfringens
Correct answer: Vibrio vulnificus
Vibrio vulnificus causes fulminant primary septicemia after raw shellfish ingestion, particularly in patients with liver disease; characteristic bullous skin lesions develop rapidly.
Question 7: A refugee from Southeast Asia presents with a chronic cough, night sweats, and weight loss for 3 months. Chest X-ray shows upper lobe cavitation. Sputum AFB smear is positive. Initial TB treatment should include how many drugs?
- 1 drug (isoniazid only)
- 2 drugs (isoniazid + rifampin)
- 3 drugs (isoniazid + rifampin + pyrazinamide)
- 4 drugs (isoniazid + rifampin + pyrazinamide + ethambutol) (Correct answer)
Correct answer: 4 drugs (isoniazid + rifampin + pyrazinamide + ethambutol)
Standard initial phase TB therapy consists of four drugs (RIPE: rifampin, isoniazid, pyrazinamide, ethambutol) for 2 months to prevent resistance while susceptibility results are pending.
Internal Medicine Exam Infectious Disease Management 4
A 50-year-old immunocompromised patient develops fever, pleuritic chest pain, and a pulmonary infiltrate with a halo sign on CT chest.
Galactomannan is positive.
What is first-line treatment?