what cause pneumonia in children
Streptococcus pneumoniae and viruses are the most common causes in infants three weeks to three months of age. Viruses are the most frequent cause of pneumonia in preschool-aged children; Streptococcus pneumoniae is the most common bacterial pathogen. Mycoplasma pneumoniae and Chlamydia pneumoniae often are the etiologic agents in children older than five years and in adolescents.