Objective: To analyze the clinical, etiological, and epidemiological aspects of community-acquired pneumonia (CAP) in hospitalized individuals. Methods: We prospectively studied 66 patients (> 14 years of age) with CAP admitted to the Hospital Estadual Sumaré, located in the Sumaré microregion of Brazil, between October of 2005 and September of 2007. We collected data related to clinical history, physical examination, pneumonia severity index (PSI) scores, and laboratory tests (blood culture; sputum smear microscopy and culture; serology for Chlamydophila pneumoniae, Mycoplasma pneumoniae, and Legionella pneumophila; and detection of Legionella sp. and Streptococcus pneumoniae antigens in urine). Results: The mean age of patients was 53 years. Most had a low level of education, and 55.7% presented with at least one comorbidity at the time of hospitalization. The proportion of elderly people vaccinated against influenza was significantly lower among the inpatients than in the general population of the Sumaré microregion (52.6% vs. > 70%). Fever was less common among the elderly patients (p < 0.05). The clinical evolution was associated with the PSI scores but not with age. The etiology was confirmed in 31 cases (50.8%) and was attributed to S. pneumoniae, principally detected by the urinary antigen test, in 21 (34.4%), followed by C. pneumoniae, in 5 (8.2%). The mortality rate was 4.9%, and 80.3% of the patients were classified as cured at discharge. Conclusions: The knowledge of the etiologic profile of CAP at the regional level favors the appropriate choice of empirical treatment, which is particularly relevant in elderly patients and in those with comorbidities. The lack of influenza vaccination in elderly patients is a risk factor for hospitalization due to CAP.

Keywords: Chlamydophila pneumoniae; Community-acquired infections; Pneumonia; Streptococcus pneumoniae; Influenza vaccines.