Which pathogen is the most common causative agent of uncomplicated Community-Acquired Pneumonia (CAP) in outpatient adults across all age groups?
Answer and explanation
Correct answer: D. Streptococcus pneumoniae
- Step 1: Review microbiological epidemiology of community-acquired pulmonary infections.
- Step 2: Streptococcus pneumoniae (pneumococcus) remains the predominant bacterial pathogen responsible for typical community-acquired pneumonia worldwide in adults, presenting classically with lobar consolidation and productive rust-colored sputum.
Answer
Streptococcus pneumoniae.
Why not the others: Mycoplasma pneumoniae causes atypical walking pneumonia in younger cohorts; Legionella is associated with contaminated aerosolized water systems; Klebsiella predominantly affects patients with chronic alcohol use disorder.
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