Background: During one year (1988), a protocol study of the community-acquired pneumonias was carried out in patients referred to the Hospital Virgen del Camino in Pamplona (Health Area I or Northern Navarra), so as to have an epidemiological and microbiological knowledge of this disease in this geographic area.
Methods: A clinical protocol, microbiological investigation, 3 blood cultures, Gram stain and sputum culture and serological tests at admission and 20 days later (complement fixing antibodies and indirect immunofluorescence) were carried out. Chest radiographs were carried out on admission, on the third and seventh hospital days and subsequently depending on the evolution.
Results: The causative organism was found in 141 of the 225 included patients (62%). Two or more organisms were identified in 19 (8%). In 84 (38%) no microorganism was found. The results for the causative organisms and their frequency were: Pneumococcus 12%, mycoplasma 12%, other bacteria (including Legionella) 11%, Q fever 8%, viruses 7%, and psitaccosis 4%. In 59% of patients there was an underlying disease and 39% developed complications. 4% of patients died.
Conclusions: 22% of the community acquired pneumonias were cared for in the hospital, representing 6% of the admissions to the Internal Medicine Service. The etiologic diagnosis was made in 62% of the community-acquired pneumonias. 23% were of bacterial origin (including Legionella) and 31% were nonbacterial. There was a high incidence of pneumonias caused by Mycoplasma pneumoniae and Coxiella burnetii.