RESUMO
BACKGROUND: Community-acquired pneumonia (CAP) that requires hospitalization, is a common and serious disease. A permanent assessment in specialized centers, to define therapeutic guidelines according to local epidemiological factors, is mandatory. AIM: To study the etiology of CAP requiring hospital admission. PATIENTS AND METHODS: Adult patients with CAP, admitted to the Clinical Hospital of the University of Chile between 1999 and 2001 were studied. A clinical, radiological and microbiological assessment was done in all patients. Blood and sputum cultures and serology for Chlamydia and Mycoplasma pneumoniae were performed. RESULTS: Thirty one patients aged 62 +/- 18 years, 12 female, met inclusion criteria. An etiologic diagnosis was made in 74 per cent of cases, (52 per cent definitive, 22 per cent probable). Frequency of definitive diagnosis was: 25 per cent Mycoplasma pneumoniae, 19 per cent Chlamydia pneumoniae and 13 per cent Streptococcus pneumoniae. Mixed etiology was found in 16 per cent and a final diagnosis was not obtained in 26 per cent of the cases. No correlation was found between clinical and radiological patterns, and the etiologic agent. C reactive protein and erythrosedimentation rate were significantly higher in CAP due to Chlamydia and Streptococcus pneumoniae. CONCLUSIONS: The higher frequency of Mycoplasma and Chlamydia pneumoniae, than previously reported, suggests that atypical agents should be considered in the initial antimicrobial therapy prescribed to these patients.