Check out today’s Step 1 Qmax Question Challenge.
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A 25-year-old medical student presents to the clinic with a nonproductive cough, low-grade fever, and malaise of 3 weeks’ duration. A few friends in his study group have been complaining of similar symptoms. The patient denies exposure to farm animals, travel, or HIV.
In clinic, vital signs are:
Temperature: 37.2°C (99°F)
Heart rate: 80 beats/min
Respiratory rate: 18 breaths/min
Blood pressure: 110/75 mm Hg
Oxygen saturation: 96% on room air (normal range: 95%–99%)
On physical examination, lungs are clear to auscultation bilaterally without egophony or dullness to percussion. Sputum cultures are negative. The physician treats for an atypical pneumonia.
Which of the following is the most sensitive method for identifying the most likely causative pathogen?
A. Cold agglutinin test
B. Eosinophil cationic protein
C. Giemsa stain
D. Gram stain
E. Nasopharyngeal polymerase chain reaction
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