Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2011 Aug;66(8):663-8.
doi: 10.1136/thx.2010.156406. Epub 2011 May 26.

Emergence of parapneumonic empyema in the USA

Carlos G Grijalva  1 , Yuwei Zhu, J Pekka Nuorti, Marie R Griffin
Affiliations

Emergence of parapneumonic empyema in the USA

Carlos G Grijalva et al. Thorax. 2011 Aug.

Abstract

Background: Although recent reports suggest that the incidence of parapneumonic empyema has increased in several regions of the USA, national trends in disease burden are unknown. National trends in the incidence of parapneumonic empyema hospitalisations and changes in empyema by associated pathogens were examined.

Methods: National hospitalisation data (1996-2008) were analysed and rates estimated using census estimates as denominators. Incidence rate ratios (IRR) compared 2008 with 1996 rates. Discharge diagnosis codes were used to characterise pathogens associated with empyema hospitalisations.

Results: Overall, national parapneumonic empyema-related hospitalisation rates increased from 3.04 per 100,000 in 1996 to 5.98 per 100,000 in 2008, a 2.0-fold increase (95% CI 1.8 to 2.1). The increases were observed among children (IRR 1.9 (95% CI 1.4 to 2.7)) and adults aged 18-39, 40-64 and ≥65 years (IRR 1.8 (95% CI 1.5 to 2.1), 2.0 (95% CI 1.6 to 3.1) and 1.7 (95% CI 1.5 to 2.0), respectively). Overall, pneumococcal empyema rates remained relatively stable in all age groups whereas streptococcal- (non-pneumococcal) and staphylococcal-related empyema rates increased 1.9-fold and 3.3-fold, respectively, with consistent increases across age groups. The overall in-hospital case fatality ratio for parapneumonic empyema-related hospitalisations was 8.0% (95% CI 6.4% to 9.5%) in 1996 and 7.2% (95% CI 6.3% to 8.1%) in 2008 (p=0.395). Of the empyemas where study pathogens were listed (37.6%), staphylococcal-related empyema had the largest absolute increases across age groups and was associated with longer hospital stay and higher in-hospital mortality than other empyemas.

Conclusions: Although parapneumonic empyema-related hospitalisations remained relatively rare, they increased substantially during the study period. A number of pathogens, especially staphylococcus, contributed to this increase.

PubMed Disclaimer

Conflict of interest statement

Potential conflicts of interest. Dr. Grijalva received lecture fees from Wyeth (now Pfizer) and has been a consultant for Glaxo Smith Kline. Dr. Griffin received grant support from MedImmune. Drs. Grijalva and Griffin received research support for an investigator-originated project from Wyeth (now Pfizer). No other potential conflict of interest relevant to this article was reported.

Figures

Figure 1
Figure 1. Trends in parapneumonic empyema-related hospitalizations, United States 1996–2008
Date are from the Nationwide Inpatient Sample.
Figure 2
Figure 2. Trends in parapneumonic empyema-related hospitalizations by different pathogens, United States 1996–2008
Date are from the Nationwide Inpatient Sample. *Note the scale change for other/unknown empyema estimates.
See this image and copyright information in PMC

Comment in

References

    1. Septimus E. Pleural Effusion and Empyema. In: Mandell GL, Bennett JERD, editors. Mandell, Douglas, and Bennett’s principles and practice of infectious diseases. Edinburgh: Churchill Livingstone; 2009. pp. 917–924. An imprint of ELSEVIER.
    1. Ashbaugh DG. Empyema thoracis. Factors influencing morbidity and mortality. Chest. 1991 May;99(5):1162–1165. - PubMed
    1. Ahmed RA, Marrie TJ, Huang JQ. Thoracic empyema in patients with community-acquired pneumonia. Am J Med. 2006 Oct;119(10):877–883. - PubMed
    1. Finley C, Clifton J, Fitzgerald JM, Yee J. Empyema: an increasing concern in Canada. Can Respir J. 2008 Mar;15(2):85–89. - PMC - PubMed
    1. Li ST, Gates RL. Primary operative management for pediatric empyema: decreases in hospital length of stay and charges in a national sample. Arch Pediatr Adolesc Med. 2008 Jan;162(1):44–48. - PubMed

Publication types

MeSH terms