An eighteen-month prospective study designed to determine the incidence, etiology and prognosis of community acquired pneumonia (CAP) in adults requiring admission to hospital.
Methods: We studied 366 patients admitted to hospital after being diagnosed of CAP at the Emergency Room of a General Hospital. Standard laboratory methods were used for culture from blood and sputum, and serology tests for Legionella pneumophila. Mycoplasma pneumoniae, Chlamydia psittaci and Coxiella burnetti. Patients were evaluated until complete recovery, paying special attention to prognostic factors predictive of death.
Results: An etiological diagnosis was established in 99 patients (27.6%). Legionella pneumophila was the most common pathogen accounting for 30 cases (8.2%), followed by Streptococcus pneumoniae with 26 cases. 26 patients died (mortality rate of 7%); factors predictive of death included pre-existing disease, tachypnea and elevated blood urea nitrogen level.
Conclusions: CAP represented 4.4% of admissions. Legionella pneumophila was the most frequently identified pathogen. If tachypnea and/or uremia are noted on admission, there is an increase in the risk of death.