Community-Acquired Pneumonia : Etiology, Epidemiology, and Outcome at a Teaching Hospital in Argentina

摘要

Objective: To survey the etiology and epidemiology of community-acquired pneumonia (CAP) innrelation to age, comorbidity, and severity and to investigate prognostic factors.nDesign: Prospective epidemiologic study, single center.nSetting: University hospital at Buenos Aires, Argentina.nPatients: Outpatients and inpatients fulfilling clinical criteria of CAP.nInterventions: Systematic laboratory evaluation for determining the etiology, and clinical evaluationnstratifying patients into mild, moderate, and severe CAP (groups 1 to 3), a clinical rule usednfor hospitalization.nResults: During a 12-month period, 343 patients (mean age, 64.4 years; range, 18 to 102 years)nwere evaluated. We found 167 microorganisms in 144 cases (yield, 42%). Streptococcus pneumoniae,nthe most common pathogen, was isolated in 35 cases (24%). Mycoplasma pneumoniae,npresent in 19 (13%), was second in frequency in group 1; Haemophilus influenzae, present in 17ncases (12%), was second in group 2; and Chlamydia pneumoniae, present in 12 cases (8%), wasnsecond in group 3. Etiology could not be determined on the basis of clinical presentation;nidentifying the etiology had no impact on mortality. Some findings were associated with specificncausative organisms and outcome. A significantly lower number of nonsurvivors receivednadequate therapy (50% vs 77%).nConclusions: Age, comorbidities, alcohol abuse, and smoking were related with distinct etiologies.nPaO2 to fraction of inspired oxygen ratio < 250, aerobic Gram-negative pathogen, chronic renalnfailure, Glasgow score < 15, malignant neoplasm, and aspirative pneumonia were associated withnmortality by multivariate analysis. Local microbiologic data could be of help in tailoringntherapeutic guidelines to the microbiologic reality at different settings. The stratification schemanand the clinical rule used for hospitalization were useful.