title: Aetiology of community-acquired pneumonia among adults in an H1N1 pandemic year: the role of respiratory viruses.
abstract: This study aimed to determine the aetiology of community-acquired pneumonia (CAP) by adding polymerase chain reaction (PCR) to conventional methods and to describe the clinical and laboratory features between patients with bacterial pneumonia (BP) and viral pneumonia (VP). Adults with CAP admitted from November 2009 to October 2010 were included. Demographics, comorbidities, severity and clinical features were recorded. Conventional microbiological methods included blood and sputum cultures, acute and convalescent serologic samples, and antigen urinary detection. New methods included multiplex PCR for Mycoplasma pneumoniae, Legionella pneumophila, Chlamydophila pneumoniae, Bordetella pertussis and 15 respiratory viruses. A total of 169 patients were included. Using conventional methods, we identified a pathogen in 51 % of cases. With PCR, up to 70 % of cases had an aetiological diagnosis. Forty-five patients had BP (34 %), 22 had VP (17 %) and 25 (19 %) had co-infection (BP and VP). Pneumococci and respiratory syncytial virus (RSV) were the most frequently identified pathogens. Procalcitonin (PCT) and C-reactive protein (CRP) median values were significantly higher in BP than in VP patients. Shaking chills, higher CURB score and shock were significantly more frequent in BP. A viral infection was identified in more than one-third of patients with CAP. Clinical and laboratory features could help to differentiate between VP and BP and to guide empirical therapy.
authors.affiliation: Service of Internal Medicine, Hospital Universitari Mútua Terrassa, Barcelona, Spain. annasangil@yahoo.com
authors.forename: A
authors.initials: A
authors.lastname: Sangil
authors.forename: E
authors.initials: E
authors.lastname: Calbo
authors.forename: A
authors.initials: A
authors.lastname: Robles
authors.forename: S
authors.initials: S
authors.lastname: Benet
authors.forename: M E
authors.initials: ME
authors.lastname: Viladot
authors.forename: V
authors.initials: V
authors.lastname: Pascual
authors.forename: E
authors.initials: E
authors.lastname: Cuchí
authors.forename: J
authors.initials: J
authors.lastname: Pérez
authors.forename: B
authors.initials: B
authors.lastname: Barreiro
authors.forename: B
authors.initials: B
authors.lastname: Sánchez
authors.forename: J
authors.initials: J
authors.lastname: Torres
authors.forename: L
authors.initials: L
authors.lastname: Canales
authors.forename: J A
authors.initials: JA
authors.lastname: De Marcos
authors.forename: J
authors.initials: J
authors.lastname: Garau
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015373:Bacterial Typing Techniques; D001886:Bordetella pertussis / Q000235:genetics / Q000302:isolation & purification; D016993:Chlamydophila pneumoniae / Q000235:genetics / Q000302:isolation & purification; D060085:Coinfection / Q000453:epidemiology / Q000382:microbiology / Q000821:virology; D017714:Community-Acquired Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology / Q000821:virology; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000453:epidemiology / Q000382:microbiology; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000453:epidemiology / Q000821:virology; D016952:Legionella pneumophila / Q000235:genetics / Q000302:isolation & purification; D008297:Male; D008875:Middle Aged; D060885:Multiplex Polymerase Chain Reaction; D009177:Mycoplasma pneumoniae / Q000235:genetics / Q000302:isolation & purification; D058873:Pandemics; D018410:Pneumonia, Bacterial / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology; D011024:Pneumonia, Viral / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology; D011446:Prospective Studies; D018357:Respiratory Syncytial Virus Infections / Q000175:diagnosis / Q000453:epidemiology / Q000821:virology; D018113:Respiratory Syncytial Virus, Human / Q000302:isolation & purification / Q000472:pathogenicity; D012621:Seasons; D012720:Severity of Illness Index; D013030:Spain / Q000453:epidemiology