Community-acquired bacterial pneumonia (CABP) is an acute infection that involves the lungs. CABP is associated with symptoms such as fever or, chills, rigors, cough, chest pain, or dyspnea, and accompanied by the presence of a new lobar or multilobar infiltrate on a chest radiograph. Streptococcus pneumoniae is the most commonly identified bacterium in CABP. Other bacteria that cause CABP include Haemophilus influenzae, Staphylococcus aureus, Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Legionella species. A causative agent is not identified in 30 percent to 50 percent of cases with currently employed diagnostic techniques.
The economic burden associated with community-acquired pneumonia (including non-bacterial causes) remains substantial at greater than $17 billion annually in the United States. Despite the availability and widespread adherence to recommended treatment guidelines, the disease continues to present a significant burden in adults. Furthermore, given the aging population, clinicians can expect to encounter an increasing number of adult patients with the disease.