title: Incidence and etiologies of complicated parapneumonic effusions in children, 1996 to 2001.
abstract: BACKGROUND
  The incidence and causative organisms associated with complicated parapneumonic effusions in children with community-acquired pneumonia are likely to have changed during the past several years.
  
  
  METHODS
  Data regarding clinical and laboratory features were abstracted retrospectively from medical records of 76 subjects with complicated parapneumonic effusions at a tertiary children's hospital from 1996 through 2001. Incidence rates per 10 000 hospital discharges and per 1000 patients with nonviral pneumonia were calculated.
  
  
  RESULTS
  Etiologic organisms were Streptococcus pneumoniae (31 subjects), Staphylococcus aureus (7), Streptococcus pyogenes (5), Abiotrophia sp. (1) and no culture-confirmed agent (32). The annual incidence of complicated parapneumonic effusions per 10 000 discharges progressively increased from 4.5 in 1996 to 25.0 in 1999 (P = 0.0001), then declined to 10.1 in 2001 (P = 0.03). Similarly the incidence per 1000 cases of nonviral pneumonia increased from 2.9 in 1996 to 11.0 in 1999 (P = 0.003) and then declined to 4.8 in 2001 (P = 0.053). Whereas S. pneumoniae was the leading confirmed etiology in each year, the proportion of cases caused by Staphylococcus aureus increased from 6% in 1996 to 2000 (all of which were methicillin-susceptible) to 30% in 2001 (all methicillin-resistant; P = 0.04).
  
  
  CONCLUSIONS
  The incidence of complicated parapneumonic effusions in children with community-acquired pneumonia increased from 1996 to 1999 and then declined concomitant with the introduction of the pneumococcal conjugate vaccine. Although cases caused by S. pneumoniae have decreased, community onset methicillin-resistant Staphylococcus aureus has emerged as a cause of pneumonia with complicated effusions in children.
authors.affiliation: Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, USA.
authors.forename: Steven C
authors.initials: SC
authors.lastname: Buckingham
authors.forename: Michaela D
authors.initials: MD
authors.lastname: King
authors.forename: Martha L
authors.initials: ML
authors.lastname: Miller
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D017714:Community-Acquired Infections / Q000453:epidemiology* / Q000382:microbiology; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006776:Hospitals, Pediatric; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008826:Microbial Sensitivity Tests; D010996:Pleural Effusion / Q000453:epidemiology* / Q000382:microbiology*; D018410:Pneumonia, Bacterial / Q000453:epidemiology* / Q000382:microbiology; D011336:Probability; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D017678:Sex Distribution; D013211:Staphylococcus aureus / Q000302:isolation & purification; D018709:Statistics, Nonparametric; D013296:Streptococcus pneumoniae / Q000302:isolation & purification; D013297:Streptococcus pyogenes / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents