title: Survey of childhood empyema in Asia: implications for detecting the unmeasured burden of culture-negative bacterial disease.
abstract: BACKGROUND
  Parapneumonic empyema continues to be a disease of significant morbidity and mortality among children despite recent advances in medical management. To date, only a limited number of studies have assessed the burden of empyema in Asia.
  
  
  METHODS
  We surveyed medical records of four representative large pediatric hospitals in China, Korea, Taiwan and Vietnam using ICD-10 diagnostic codes to identify children <16 years of age hospitalized with empyema or pleural effusion from 1995 to 2005. We also accessed microbiology records of cultured empyema and pleural effusion specimens to describe the trends in the epidemiology and microbiology of empyema.
  
  
  RESULTS
  During the study period, we identified 1,379 children diagnosed with empyema or pleural effusion (China, n = 461; Korea, n = 134; Taiwan, n = 119; Vietnam, n = 665). Diagnoses of pleural effusion (n = 1,074) were 3.5 times more common than of empyema (n = 305), although the relative proportions of empyema and pleural effusion noted in hospital records varied widely between the four sites, most likely because of marked differences in coding practices. Although pleural effusions were reported more often than empyema, children with empyema were more likely to have a cultured pathogen. In addition, we found that median age and gender distribution of children with these conditions were similar across the four countries. Among 1,379 empyema and pleural effusion specimens, 401 (29%) were culture positive. Staphylococcus aureus (n = 126) was the most common organism isolated, followed by Streptococcus pneumoniae (n = 83), Pseudomonas aeruginosa (n = 37) and Klebsiella (n = 35) and Acinetobacter species (n = 34).
  
  
  CONCLUSIONS
  The age and gender distribution of empyema and pleural effusion in children in these countries are similar to the US and Western Europe. S. pneumoniae was the second leading bacterial cause of empyema and pleural effusion among Asian children. The high proportion of culture-negative specimens among patients with pleural effusion or empyema suggests that culture may not be a sufficiently sensitive diagnostic method to determine etiology in the majority of cases. Future prospective studies in different countries would benefit from standardized case definitions and coding practices for empyema. In addition, more sensitive diagnostic methods would improve detection of pathogens and could result in better prevention, treatment and outcomes of this severe disease.
authors.affiliation: Division of Translational Research, International Vaccine Institute, Seoul, South Korea. bnyam@ivi.int
authors.forename: Batmunkh
authors.initials: B
authors.lastname: Nyambat
authors.forename: Paul E
authors.initials: PE
authors.lastname: Kilgore
authors.forename: Dong Eun
authors.initials: DE
authors.lastname: Yong
authors.forename: Dang Duc
authors.initials: DD
authors.lastname: Anh
authors.forename: Chen-Hsun
authors.initials: CH
authors.lastname: Chiu
authors.forename: Xuzhuang
authors.initials: X
authors.lastname: Shen
authors.forename: Luis
authors.initials: L
authors.lastname: Jodar
authors.forename: Timothy L
authors.initials: TL
authors.lastname: Ng
authors.forename: Hans L
authors.initials: HL
authors.lastname: Bock
authors.forename: William P
authors.initials: WP
authors.lastname: Hausdorff
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D001208:Asia / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D003470:Culture Media; D016724:Empyema, Pleural / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology; D006090:Gram-Negative Bacteria / Q000302:isolation & purification; D016905:Gram-Negative Bacterial Infections / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology; D006094:Gram-Positive Bacteria / Q000302:isolation & purification; D016908:Gram-Positive Bacterial Infections / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D007223:Infant; D010996:Pleural Effusion / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology
chemical_list: D003470:Culture Media