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Difficulty: MediumInfectious Diseases

For each immunocompromised patient described below, pair their clinical presentation with the most appropriate definitive targeted antimicrobial regimen for their suspected or confirmed opportunistic infection.

  • A patient with a CD4 count of 130 cells/mm³, progressive dyspnea on exertion, dry cough, and chest imaging showing bilateral ground-glass opacities.High-dose trimethoprim-sulfamethoxazole
  • A patient with a CD4 count of 60 cells/mm³, new-onset seizures, headache, and a brain MRI revealing multiple ring-enhancing lesions in the basal ganglia.Pyrimethamine, sulfadiazine, and leucovorin
  • A patient with a CD4 count of 35 cells/mm³, persistent fevers, drenching night sweats, weight loss, and blood cultures growing acid-fast bacilli.Clarithromycin and ethambutol
  • A patient with a CD4 count of 180 cells/mm³, severe retrosternal pain upon swallowing, and endoscopy revealing white, plaque-like lesions throughout the esophagus.Systemic fluconazole

Answer

The patient with bilateral ground-glass opacities (PCP) is matched with high-dose trimethoprim-sulfamethoxazole. The patient with multiple ring-enhancing lesions (Toxoplasmosis) is matched with pyrimethamine, sulfadiazine, and leucovorin. The patient with systemic symptoms and acid-fast bacilli (MAC) is matched with clarithromycin and ethambutol. The patient with odynophagia and esophageal plaques (Candida esophagitis) is matched with systemic fluconazole.
The correct pairings rely on pattern recognition of classic AIDS-defining illnesses. A CD4 count < 200 with interstitial pneumonia indicates PCP (requires TMP-SMX). A CD4 count < 100 with ring-enhancing brain lesions indicates Toxoplasmosis (requires pyrimethamine and sulfadiazine). A CD4 count < 50 with disseminated symptoms and acid-fast bacilli indicates MAC (requires clarithromycin and ethambutol). Odynophagia with white plaques indicates esophageal candidiasis (requires systemic fluconazole).

Step-by-Step Solution

1
Analyze the CD4 count and clinical syndrome for each patient to identify the specific opportunistic infection.
Identified the pathogens as Pneumocystis jirovecii, Toxoplasma gondii, Mycobacterium avium complex, and Candida albicans, respectively.
Different opportunistic infections predictably manifest when CD4 counts fall below specific thresholds (200, 100, and 50 cells/mm³), creating distinct clinical profiles.
2
Assign the guideline-recommended first-line pharmacotherapy for each identified active infection.
Paired PCP with TMP-SMX, Toxoplasmosis with pyrimethamine/sulfadiazine/leucovorin, MAC with clarithromycin/ethambutol, and Candida esophagitis with fluconazole.
Applying the correct targeted antimicrobial stewardship avoids treatment failure and minimizes inappropriate antibiotic exposure.

Key Concept

Diagnosis and targeted treatment of major HIV-associated opportunistic infections based on clinical presentation and CD4 cell count strata.
Estimated Time:1m 30s
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Topics

Infectious Diseases

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