Research article

Survey of childhood empyema in Asia: Implications for detecting the unmeasured burden of culture-negative bacterial disease

Batmunkh Nyambat¹ , Paul E Kilgore¹ , Dong Eun Yong² , Dang Duc Anh³ , Chen-Hsun Chiu⁴ , Xuzhuang Shen⁵ , Luis Jodar¹ , Timothy L Ng⁶ , Hans L Bock⁶ and William P Hausdorff⁶

¹Division of Translational Research, International Vaccine Institute, Seoul, South Korea

²Department of Laboratory Medicine, College of Medicine, Yonsei University, Seoul, South Korea

³National Institute of Hygiene and Epidemiology, Hanoi, Vietnam

⁴Chang Gung Children's Hospital and Chang Gung University College of Medicine, Taipei, Taiwan

⁵Beijing Children's Hospital affiliated to Capital Medical University, Beijing, PR China

⁶GlaxoSmithKline Biologicals, Rixensart, Belgium

author email corresponding author email

BMC Infectious Diseases 2008, 8:90doi:10.1186/1471-2334-8-90

Published:	11 July 2008

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).

Conclusion

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.