Program Schedule

958
Streptococcus pneumoniae Serotype 3 Invasive Infections in Children

Session: Poster Abstract Session: Pediatric - Bacterial Studies
Friday, October 10, 2014
Room: The Pennsylvania Convention Center: IDExpo Hall BC
Posters
  • Serotype 3 _IDSA2014final.pdf (656.3 kB)
  • Background: Invasive pneumococcal infections (IPI) due to Streptococcus pneumoniae serotype (ST) 3 have not declined as dramatically in children as other vaccine STs since the introduction in 2010 of the 13-valent pneumococcal conjugate vaccine, PCV13. While persistence of ST 3 isolates is likely due to capsule characteristics, genotypes with greater fitness may also emerge. We analyzed molecular characteristics of  S. pneumoniae ST 3 isolates that were obtained from children with IPI.

    Methods: IPI cases at 8 children’s hospitals in the United States were prospectively identified from 2008-2013.  ST 3 isolates were selected from the associated database. Isolates were typed by multilocus sequence typing (MLST). Select patient information was analyzed and antibiotic susceptibility patterns were compared. Statistical analysis included Wilcoxon rank-sum and Fisher's exact tests.

    Results: Sixty-three patients with 62 isolates were identified from the database (Table); 36 were male. Median age was 3.7y (0.1-17.6y). Disease presentations were pneumonia (n=33), meningitis (n=9), bacteremia (n=7), mastoiditis (n=6), cellulitis/abscess (n=7), and peritonitis (n=1). Twelve (19%) patients had an underlying condition. The MLSTs were 180 (n=58), 260, 338, 433 and 1116. The MLST distribution did not change over time. All isolates were penicillin and ceftriaxone susceptible. Only 3 were resistant to erythromycin and 2 were resistant to clindamycin.

    Table. Characteristics of pediatric serotype 3 infections, 2008-2013

    Year

    Total invasive SPN

    Serotype 3

    (% of total)

    MLST 180

    Pneumonia

    (% of total serotype 3)

    Mean Age (years)

    2008

    197

    11 (6%)

    11

    8 (73%)

    3.1

    2009

    219

    22 (10%)

    20

    7 (32%)

    5.6

    2010

    165

    8 (5%)

    7

    5 (63%)

    3.4

    2011

    128

    5 (4%)

    4

    1 (20%)

    6.2

    2012

    112

    6 (5%)

    5

    4 (67%)

    5.7

    2013

    104

    11 (11%)

    11

    8 (73%)

    6.2

    Total

     925

    63

    58

    33

    5.0

    Conclusion: ST 3 isolates chiefly caused pneumonia in this patient population and were mainly MLST180. MLST distribution did not change following introduction of PCV13. No statistical differences in distribution, age, disease presentation, age or, antibiotic susceptibility were observed. A modified vaccine, potentially including non-capsular antigens, is likely required to optimally reduce IPI due to ST 3 in children.

    Kristina G. Hulten, PhD1, Sheldon L. Kaplan, MD, FIDSA1, Donald P. Marion, BS1, Linda B. Lamberth, BS1, William J. Barson, MD2, Philana Ling Lin, MD3, Jose R. Romero, MD4, John S. Bradley, MD, FIDSA5, Tina Tan, MD, FIDSA6, Jill a. Hoffman, MD7, Laurence B. Givner, MD8 and Edward O. Mason Jr., PhD1, (1)Pediatrics, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, (2)Nationwide Children's Hospital and The Ohio State University College of Medicine, Columbus, OH, (3)Children's Hospital of Pittsburgh, Pittsburgh, PA, (4)University of Arkansas for Medical Sciences, Little Rock, AR, (5)Rady Children's Hospital - San Diego, San Diego, CA, (6)Northwestern University Feinberg School of Medicine, Chicago, IL, (7)Children's Hospital, Los Angeles, Los Angeles, CA, (8)Wake Forest University School of Medicine, Winston-Salem, NC

    Disclosures:

    K. G. Hulten, None

    S. L. Kaplan, Pfizer: Grant Investigator and Scientific Advisor, Consulting fee and Grant recipient

    D. P. Marion, None

    L. B. Lamberth, None

    W. J. Barson, UpToDate: Author, Royalty
    Pfizer: Investigator, Research support
    Wyeth: Investigator, Research support

    P. L. Lin, None

    J. R. Romero, None

    J. S. Bradley, None

    T. Tan, Pfizer/Wyeth: Scientific Advisor, Nothing to date

    J. A. Hoffman, None

    L. B. Givner, Pfizer: Investigator, Research support

    E. O. Mason Jr., None

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