Background: Parapneumonic Empyema (PPE) is a serious complication of community acquired pneumonia in children. A pathogen is identified in a minority of cases. Following licensure of the 7-valent pneumococcal conjugate vaccine (PCV7) in 2000, rates of PPE increased in the US. In 2010, PCV13 replaced PCV7. Data on the impact on PPE and the responsible pathogens are limited.
Methods: We identified Utah children <18 years hospitalized at an Intermountain Healthcare facility from 2004 to 2014 with an International Classification of Diseases, 9th Revision PPE diagnosis code (510.x) and chest tube drainage procedure code (43.x). We compared culture-confirmed and -negative PPE in the PCV7 (2004-2010) and PCV13 (2011-2014) periods. Invasive S. pneumoniae isolates from cases were serotyped.
Results: We identified 455 children hospitalized with PPE during the PCV7 and 142 children during the PCV13 period. The mean number of PPE hospitalizations decreased from 65/year in the PCV7 era to 36/year in the PCV13 era (P=0.002). A pathogen was detected in 26% and 31% of PPE cases during the two periods, respectively (Figure). The decrease was primarily due to declines in culture-negative (48/year vs. 25/year; P=0.02) and Streptococcus pneumoniae (10/year vs. 5/year; P=0.02) PPE. Staphylococcus aureus (2.6/year vs. 2.3/year; P=0.9) and Streptococcus pyogenes (4/year vs. 3.8/year; P=0.27) PPE did not change. During the PCV7 period, the most common causes of pneumococcal PPE were serotypes 19A (25%), 1 (20%), 7F (20%) and 3 (17%); during the PCV13 period, serotypes 3 (69%), 19A (13%), 1 (6%) and 22F (6%) dominated. The proportion due to serotype 3 increased significantly (17% vs. 69%; P<0.001, while the proportion due to serotype 7F (20% vs. 0%; P=0.06) and 19A (25% vs. 13%; P=0.5) decreased somewhat.
Conclusion: With PCV13 vaccine use in Utah, overall rates of pediatric PPE decreased significantly due to decreases in pneumococcal and culture-negative PPE (most often due to S. pneumoniae in earlier studies). Serotype 3 is now the predominant cause of pneumococcal PPE. Ongoing surveillance, preferably with enhanced diagnostics is needed to follow emerging trends in PPE.
S. K. Sanderson,
C. R. Stockmann, None
A. Pavia, None
E. Mason Jr, None
J. Daly, None
A. J. Blaschke, BioFire Diagnostics, LLC: Collaborator , Consultant and Scientific Advisor , Consulting fee , Licensing agreement or royalty and Research support
bioMerieux, Inc: Collaborator , Investigator and Scientific Advisor , Consulting fee and Research support
Merck: Investigator , Research grant
P. Rosen, None
E. K. Korgenski, None
C. L. Byington, NIH: Grant Investigator , Grant recipient
BioFire Diagnostics: Intellectual Property for the FilmArray , Intellectual Property