title: Community-acquired pneumonia: etiology, epidemiology, and outcome at a teaching hospital in Argentina.
abstract: OBJECTIVE
  To survey the etiology and epidemiology of community-acquired pneumonia (CAP) in relation to age, comorbidity, and severity and to investigate prognostic factors.
  
  
  METHODS
  Prospective epidemiologic study, single center.
  
  
  METHODS
  University hospital at Buenos Aires, Argentina.
  
  
  METHODS
  Outpatients and inpatients fulfilling clinical criteria of CAP.
  
  
  METHODS
  Systematic laboratory evaluation for determining the etiology, and clinical evaluation stratifying patients into mild, moderate, and severe CAP (groups 1 to 3), a clinical rule used for hospitalization.
  
  
  RESULTS
  During a 12-month period, 343 patients (mean age, 64.4 years; range, 18 to 102 years) were evaluated. We found 167 microorganisms in 144 cases (yield, 42%). Streptococcus pneumoniae, the most common pathogen, was isolated in 35 cases (24%). Mycoplasma pneumoniae, present in 19 (13%), was second in frequency in group 1; Haemophilus influenzae, present in 17 cases (12%), was second in group 2; and Chlamydia pneumoniae, present in 12 cases (8%), was second in group 3. Etiology could not be determined on the basis of clinical presentation; identifying the etiology had no impact on mortality. Some findings were associated with specific causative organisms and outcome. A significantly lower number of nonsurvivors received adequate therapy (50% vs 77%).
  
  
  CONCLUSIONS
  Age, comorbidities, alcohol abuse, and smoking were related with distinct etiologies. PaO(2) to fraction of inspired oxygen ratio < 250, aerobic Gram-negative pathogen, chronic renal failure, Glasgow score < 15, malignant neoplasm, and aspirative pneumonia were associated with mortality by multivariate analysis. Local microbiologic data could be of help in tailoring therapeutic guidelines to the microbiologic reality at different settings. The stratification schema and the clinical rule used for hospitalization were useful.
authors.affiliation: Pulmonary Division, Department of Medicine, Hospital de Clínicas "José de San Martín," Faculty of Biochemistry, University of Buenos Aires, Argentina.
authors.forename: C M
authors.initials: CM
authors.lastname: Luna
authors.forename: A
authors.initials: A
authors.lastname: Famiglietti
authors.forename: R
authors.initials: R
authors.lastname: Absi
authors.forename: A J
authors.initials: AJ
authors.lastname: Videla
authors.forename: F J
authors.initials: FJ
authors.lastname: Nogueira
authors.forename: A D
authors.initials: AD
authors.lastname: Fuenzalida
authors.forename: R J
authors.initials: RJ
authors.lastname: Gené
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001118:Argentina / Q000453:epidemiology; D016009:Chi-Square Distribution; D023521:Chlamydophila Infections / Q000145:classification / Q000453:epidemiology; D016993:Chlamydophila pneumoniae; D017714:Community-Acquired Infections / Q000145:classification / Q000453:epidemiology* / Q000209:etiology; D015897:Comorbidity; D016021:Epidemiologic Studies; D005260:Female; D005500:Follow-Up Studies; D006192:Haemophilus Infections / Q000145:classification / Q000453:epidemiology; D006193:Haemophilus influenzae; D006760:Hospitalization; D006784:Hospitals, Teaching; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D018410:Pneumonia, Bacterial / Q000145:classification / Q000453:epidemiology* / Q000209:etiology; D011019:Pneumonia, Mycoplasma / Q000145:classification / Q000453:epidemiology; D011018:Pneumonia, Pneumococcal / Q000145:classification / Q000453:epidemiology; D011379:Prognosis; D011446:Prospective Studies; D012720:Severity of Illness Index; D015996:Survival Rate