title: Bacterial and viral etiology in hospitalized community acquired pneumonia with molecular methods and clinical evaluation.
abstract: BACKGROUND
  Polymerase chain reaction (PCR) method has improved the diagnosis rates for patients with community-acquired pneumonia (CAP). We aimed to evaluate the bacterial and viral etiology of hospitalized CAP cases and compare clinical and laboratory findings of patients with pure bacterial and bacterial and viral (mixed) infections.
  
  
  METHODS
  A total of 55 patients hospitalized with CAP were enrolled into the prospective study between February 2010 and December 2010. Clinical and laboratory follow-up were performed on days 0, 7 and 14. Deep tracheal aspiration samples were examined for bacterial and viral pathogens by multiplex PCR, and standard bacteriological culture method.
  
  
  RESULTS
  The etiological identification rate in 50 patients for bacteria, viruses and mixed virus-bacteria combination by PCR were 62%, 4%, 32%, respectively and 60% in 55 patients by bacterial culture method. Streptococcus pneumoniae concomitant with Haemophilus influenzae (36%) and rhinovirus (16%) was very common, whereas atypical pathogens (only Mycoplasma pneumoniae) were rare (6%). Rhinovirus was the most common viral agent (20%). Recently identified viruses, human coronavirus HKU1 and human bocavirus were not detected except for human metapneumovirus (one case). There was no significant difference in terms of mean age, immune status, leukocyte count, C-reactive protein (CRP) values, hospitalization duration and CURB-65 score between bacterial and mixed viral-bacterial detections. Advanced age (p < 0.01) and higher CURB-65 score (p = 0.01) were found to be associated with increased mortality.
  
  
  CONCLUSIONS
  Concomitance of bacterial and viral agents is frequent and resemble with bacterial infections alone. Further studies are needed for the clinical significance of mixed detections.
authors.affiliation: Faculty of Medicine, Ege University, Bornova, İzmir, Turkey. drderya_caglayan@yahoo.com.
authors.forename: Derya
authors.initials: D
authors.lastname: Çağlayan Serin
authors.forename: Hüsnü
authors.initials: H
authors.lastname: Pullukçu
authors.forename: Candan
authors.initials: C
authors.lastname: Ciçek
authors.forename: Oğuz Reşat
authors.initials: OR
authors.lastname: Sipahi
authors.forename: Sezai
authors.initials: S
authors.lastname: Taşbakan
authors.forename: Sabri
authors.initials: S
authors.lastname: Atalay
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D060085:Coinfection / Q000382:microbiology* / Q000821:virology*; D017714:Community-Acquired Infections / Q000382:microbiology* / Q000821:virology*; D005260:Female; D006193:Haemophilus influenzae / Q000302:isolation & purification; D006801:Humans; D009980:Influenza A virus / Q000302:isolation & purification; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D001936:Moraxella catarrhalis / Q000302:isolation & purification; D060885:Multiplex Polymerase Chain Reaction; D009177:Mycoplasma pneumoniae / Q000302:isolation & purification; D029482:Parainfluenza Virus 4, Human / Q000302:isolation & purification; D062072:Patient Acuity; D018410:Pneumonia, Bacterial / Q000382:microbiology*; D011024:Pneumonia, Viral / Q000821:virology*; D011446:Prospective Studies; D018113:Respiratory Syncytial Virus, Human / Q000302:isolation & purification; D012229:Rhinovirus / Q000302:isolation & purification; D013296:Streptococcus pneumoniae / Q000302:isolation & purification; D055815:Young Adult