title: Aetiology of community-acquired pneumonia in children treated in hospital.
abstract: Viral and bacterial antigen and antibody assays were prospectively applied to study the microbial aetiology of community-acquired pneumonia in 195 hospitalised children during a surveillance period of 12 months. A viral infection alone was indicated in 37 (19%), a bacterial infection alone in 30 (15%) and a mixed viral-bacterial infection in 32 (16%) patients. Thus, 46% of the 69 patients with viral infection and 52% of the 62 patients with bacterial infection had a mixed viral and bacterial aetiology. Respiratory syncytial virus (RSV) was identified in 52 patients and Streptococcus pneumoniae in 41 patients. The next common agents in order were non-classified Haemophilus influenzae (17 cases), adenoviruses (10 cases) and Chlamydia species (8 cases). The diagnosis of an RSV infection was based on detecting viral antigen in nasopharyngeal secretions in 79% of the cases. Pneumococcal infections were in most cases identified by antibody assays; in 39% they were indicated by demonstrating pneumococcal antigen in acute phase serum. An alveolar infiltrate was present in 53 (27%) and an interstitial infiltrate in 108 (55%) of the 195 patients. The remaining 34 patients had probable pneumonia. C-reactive protein (CRP), erythrocyte sedimentation rate and total white blood cell count were elevated in 25%, 40% and 36% of the patients, respectively. CRP was more often elevated in patients with bacterial infection alone than in those with viral or mixed viral-bacterial infections. No other correlation was seen between the radiological or laboratory findings and serologically identified viral, bacterial or mixed viral-bacterial infections.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Paediatrics, Kuopio University Hospital, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Korppi
authors.forename: T
authors.initials: T
authors.lastname: Heiskanen-Kosma
authors.forename: E
authors.initials: E
authors.lastname: Jalonen
authors.forename: P
authors.initials: P
authors.lastname: Saikku
authors.forename: M
authors.initials: M
authors.lastname: Leinonen
authors.forename: P
authors.initials: P
authors.lastname: Halonen
authors.forename: P H
authors.initials: PH
authors.lastname: Mäkela
mesh_terms: D000293:Adolescent; D001419:Bacteria / Q000302:isolation & purification; D001424:Bacterial Infections / Q000150:complications / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D006760:Hospitalization; D006801:Humans; D007223:Infant; D008168:Lung / Q000000981:diagnostic imaging; D011014:Pneumonia / Q000000981:diagnostic imaging / Q000209:etiology / Q000382:microbiology*; D011024:Pneumonia, Viral / Q000000981:diagnostic imaging / Q000209:etiology / Q000382:microbiology; D011446:Prospective Studies; D011859:Radiography; D014777:Virus Diseases / Q000150:complications / Q000382:microbiology; D014780:Viruses / Q000302:isolation & purification