The MOST COMMON causative organism for community acquired pneumonia is:: (A) Streptococcus pneumoniae, (B) Haemophilus influenzae, (C) Mycoplasma pneumoniae, (D) Chlamydia pneumoniae
Answer is A. Although Streptococcus pneumoniae is most common pathogen causing community aquoired pneumonia. Data suggest that a virus may be responsible for up to 18% of cases of CAP that require admission to the hospital. Ref: Harrison, E-18,P-2131.