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Published on: February 23, 2014

Community-acquired pneumonia of mixed etiology: prevalence, clinical characteristics, and outcome

F Gutiérrez1, M Masiá, J C Rodríguez

  • 1Unidad de Enfermedades Infecciosas, Hospital General Universitario de Elche, Camí de la Almazara s/n, 03203 Elche, Alicante, Spain. gutierrez_fel@gva.es

European Journal of Clinical Microbiology & Infectious Diseases : Official Publication of the European Society of Clinical Microbiology
|June 3, 2005
PubMed

Insights

Mixed community-acquired pneumonia (CAP) is uncommon but linked to more underlying conditions and severe outcomes. This study explored its prevalence, characteristics, and results in CAP patients.

Area of Science:

  • Infectious Diseases
  • Pulmonology
  • Microbiology

Background:

  • Community-acquired pneumonia (CAP) is a common infection.
  • The clinical significance of mixed-etiology CAP is not well understood.
  • Previous literature has increasingly noted mixed-etiology CAP.

Purpose of the Study:

  • To determine the prevalence of mixed-etiology CAP.
  • To describe the clinical characteristics of patients with mixed-etiology CAP.
  • To evaluate the outcomes of mixed-etiology CAP compared to monomicrobial CAP.

Main Methods:

  • Prospective study over 2 years.
  • Inclusion of consecutive CAP patients with extensive microbiological workup.
  • Use of predefined criteria to establish etiology.

Main Results:

  • A single pathogen was identified in 45% of cases, while 5.7% had mixed infections.
  • The most common mixed infections involved bacteria plus atypical organisms (28.6%) or two bacteria (28.6%).
  • Mixed pneumonia patients had higher rates of underlying conditions (64% vs. 45%) and complications (39.3% vs. 18.6%).

Conclusions:

  • Mixed-etiology CAP is relatively uncommon.
  • Patients with mixed CAP are more prone to comorbidities like dementia.
  • Mixed CAP may be associated with a more severe disease course and increased complications.

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