2015 HSC Section 1 Book of Articles

Reprinted by permission of Pediatr Infect Dis J. 2014; 33(10):1033-1036.

O riginal S tudies

Impact of the 13-valent Pneumococcal Conjugate Vaccine on Chronic Sinusitis Associated With Streptococcus pneumoniae in Children

Liset Olarte, MD,*† Kristina G. Hulten, PhD,*† Linda Lamberth BS,*† Edward O. Mason, Jr., PhD,*† and Sheldon L. Kaplan, MD*†

sinusitis. 4 Nevertheless, S. pneumoniae continues to represent an important pathogen among the aerobic isolates in chronic sinusi- tis, particularly in acute exacerbations of chronic sinusitis and in younger children. 2,4 After the licensure of the 7-valent pneumococcal conjugate vaccine (PCV7) in 2000, a sustained decrease in the incidence of invasive pneumococcal disease and acute otitis media (AOM) was observed. 6–8 As the isolation of S. pneumoniae declined in patients with AOM, an increase of H. influenzae isolations was described. 8,9 A similar shift in the organisms isolated from patients with acute bacterial sinusitis was reported after the introduction of PCV7. 10,11 Brook et al 10 reported a decrease of S. pneumoniae isolated from nasopharyngeal cultures obtained from children with acute sinusitis from 43% during 1996–2000 to 25% during 2001–2005 ( P = 0.0014). 10 Similar results were obtained from patients with acute sinusitis who underwent endoscopic sinus surgery (ESS). 11 The widespread use of PCV7 not only altered the pathogen- esis of bacterial sinusitis with respect to the causative pathogens, but also the serotype distribution within the pneumococcal isolates. Serotype 19A, which is not included on PCV7, was described as the most common pneumococcal serotype isolated from pediatric patients with chronic sinusitis during 2007–2008 undergoing endo- scopic sinus surgery at Texas Children’s Hospital (TCH) 12 , a finding that likely reflected the overall high prevalence of serotype 19A during that time. 13 The 13-valent pneumococcal conjugate vaccine (PCV13) that added serotypes 1, 3, 5, 6A, 7F and 19A to PCV7 was licensed in 2010. A multicenter surveillance study showed an early trend in a decrease of invasive pneumococcal disease in the year after the introduction of PCV13. 14 To our knowledge, there are no studies describing the impact of PCV13 on chronic sinusitis in children to date. The purpose of this study was to compare the distribution of pneumococcal serotypes, antibiotic susceptibilities of pneumo- coccal isolates and the distribution of co-isolated organisms from pediatric patients with chronic sinusitis at TCH before and after the introduction of PCV13. MATERIALS AND METHODS Paranasal sinuses cultures positive for S. pneumoniae have been prospectively identified at TCH as part of a pneumococ- cal surveillance study that has been approved by the Institutional Review Board of the Baylor College of Medicine. Patients with a positive sinus culture for S. pneumoniae obtained during ESS because of chronic sinusitis from August 2008 to December 2013 at TCH were included. All patients were evaluated by an otorhinolaryngologist in the outpatient setting and diagnosed with chronic sinusitis. Under endoscopic visualization, patients’ sinuses were cannulated, suctioned and irrigated with saline solution. A sample of each aspirate obtained was sent for cul- ture in the TCH Microbiology Laboratory. Pneumococcal isolates were then serotyped by the capsular swelling method using com- mercially available antisera (Statens Seruminstitut, Copenhagen,

Background: The widespread use of the 7-valent pneumococcal conjugate vaccine has been associated with epidemiologic changes of mucosal and invasive pneumococcal disease. No study describes the impact of 13-valent pneumococcal conjugate vaccine (PCV13) on chronic sinusitis in children. We describe changes in epidemiology of Streptococcus pneumoniae chronic sinusitis after the introduction of PCV13 at Texas Children’s Hospital. Methods: We identified patients <18 years with positive sinus culture for S. pneumoniae who underwent endoscopic sinus surgery because of chronic sinusitis fromAugust 2008 to December 2013 at Texas Children’s Hospital. Isolates were serotyped by the capsular swelling method. Demographic and clinical information was collected retrospectively. The χ 2 test and Fisher’s exact test were used to analyze dichotomous variables. Results: We identified 91 cases of chronic sinusitis with positive sinus cul- ture for S. pneumoniae . Sixty-one (67%) isolates were non-PCV13 sero- types. PCV13 cases decreased 31% in the post-PCV13 period ( P = 0.003). Serotype 19A decreased 27% in the post-PCV13 period ( P = 0.007), but accounted for all the isolates with penicillin minimal inhibitory concentra- tion ≥ 4 μ g/mL and ceftriaxone minimal inhibitory concentration ≥ 2 μ g/mL. Serotypes 19A (38%) and 15C (17%) were the most common in the pre- and post-PCV13 periods, respectively. The most common organism co-isolated was Haemophilus influenzae (52%). Isolation of Prevotella spp. increased in the post-PCV13 period ( P = 0.02). Conclusions: S. pneumoniae continues to represent an important pathogen in chronic sinusitis in children <5 years of age. After the introduction of PCV13, S. pneumoniae isolation declined in children with chronic sinusitis at Texas Children’s Hospital. We also observed a substantial reduction of PCV13 serotypes, predominantly serotype 19A. KeyWords: Streptococcus pneumoniae , sinusitis, pneumococcal conjugate vaccine S t reptococcus pneumoniae (~30%) has been described as the most common pathogen in acute bacterial sinusitis in children followed by Haemophilus influenza e and Moraxella catarrha- lis (~20% each). 1 Studies describing the pathogenesis of chronic sinusitis report a predominance of anaerobes in adults. 2,3 How- ever, results are variable in children, 4,5 with some studies reporting bacteriologic characteristics of chronic sinusitis similar to acute Accepted for publication April 16, 2014. From the *Department of Pediatrics, Section of Pediatric Infectious Diseases, Baylor College of Medicine; and †Texas Children’s Hospital, Houston, TX. This study supported in part by grant from Pfizer for Streptococcus pneumoniae surveillance study. The authors have no other funding or conflicts of interest to disclose. Address for correspondence: Sheldon L. Kaplan, MD, Texas Children’s Hospital, Feigin Center, Suite 1150, 1102 Bates Ave., Houston, TX 77030. E-mail: skaplan@bcm.edu. ( Pediatr Infect Dis J 2014;33:1033–1036)

Copyright © 2014 by Lippincott Williams & Wilkins ISSN: 0891-3668/14/3310-1033 DOI: 10.1097/INF.0000000000000387

www.pidj.com |

The Pediatric Infectious Disease Journal  • Volume 33, Number 10, October 2014

143