Bacterial Pneumonia

Paul C. Stillwell, MD, FAAP

Introduction/Etiology/Epidemiology

•Pneumonia in children is categorized in the following ways to help differentiate the potential infecting organisms, treatment strategies, and expected outcomes:

—Community-acquired pneumonia (CAP) in an otherwise healthy child

—Health care–related pneumonia or hospital-acquired pneumonia

—Pneumonia in an immunocompromised patient

—Pneumonia with complications (effusion, empyema, abscess)

•The incidence of CAP is highest in children <4 years of age— approximately 35–40 per 1,000, compared to only 20 per 1,000 school-aged children and 10 per 1,000 teenagers and adolescents.

•Pneumonia is a common cause of death in children who reside in underserved countries.

•The prevalence of bacterial pneumonia in CAP in children is ≤10% overall; it is less frequent in younger children and more common in teenagers and adolescents.

•Mycoplasma is emerging as the most common bacterial cause of CAP in hospitalized children. In a study of hospitalized children with CAP in 3 U.S. cities, Mycoplasma was identified in 2% of the children <2 years of age and 23% of the adolescents.

•Streptococcus pneumoniae accounts for 3%–4% of cases, and Staphylococcus aureus accounts for about 1% of cases across all age groups. These organisms may account for a higher percentage of pneumonias in developing countries.

•The spectrum of bacterial agents that causes pneumonia in children with incomplete immune function includes not just streptococci and staph-ylococci, but also Pseudomonas aeruginosa, Klebsiella species, Legionella, Enterobacter, Acinetobacter, Stenotrophomonas maltophilia, Burkholderia cepacia, and anaerobes.

•Viral, fungal, and mycobacterial infections should also be considered as etiologic origins in the immunocompromised child.

•The most common symptoms of bacterial pneumonia are cough, fever, and shortness of breath.

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