1760. Haemophilus influenzae type b (Hib) Invasive Disease in Amish Children, Missouri 2014
Session: Poster Abstract Session: Pediatric Bacterial Infections
Saturday, October 10, 2015
Room: Poster Hall
Posters
  • Hib Poster ID Week 2015 rev 3 FINAL.pdf (514.5 kB)
  • Background: Hib invasive infection is rarely identified in the US since the advent of conjugate vaccine in the early 1990s. We identified 3 cases of invasive Hib disease during the first 5 months of 2014, all in unimmunized Amish children from 2 different communities. The molecular/genetic characteristics of Hib strains isolated in a Missouri cluster of Hib cases are described and compared to those identified in the multilocus sequence type (MLST) data bank which consists of 598 strains from 6 countries.   

    Methods: The H. influenzae strains were tested by PCR for presence of capsule genes bexA and bexB, located in the ATP transport Region I of the cap locus, and for specific capsule types a through f as previously described and for sodC to distinguish Division I (sodC  -) from Division II (sodC  +) H. influenzae. MLST was performed using the 7 standard MLST alleles and whole genomes of all 3 H. influenzae strains were sequenced by Illumina and strain 1 by PacBio.

    Results:

    Three children presented with invasive Hib diseases characteristic of the pre-vaccine era between Jan-May, 2014. Children in community A resided in small towns less than 10 miles apart, and were infected with highly similar strains identified as ST45. The third child resided 250 miles south of community A and was infected with a genetically different strain. The ST45 strain is rarely reported and represents only 3/598 (0.5%) of strains in the MLST data bank. The 3 previously identified ST45 strains were confirmed 15 years ago in a Pennsylvania outbreak in 3 Amish communities.

    Patient # (age)

    Date

    Infection

     

    Community

    Capsule genes

    sodC

    MLST

    sequence

    type

    Outcome

    bexA

    bexB

    1(13mo)

    Jan ‘14

    Septic arthritis

    Recovered

    B

    positive

    positive

    negative

    ST6

    2 (2 yr)

    Feb ‘14

    Epiglottitis

    Death

    A

    positive

    positive

    negative

    ST45

    3(13mo)

    May ’14

    Osteomyelitis with septic arthritis

    Recovered

    A

    positive

    positive

    negative

    ST45

    Conclusion:

    Two of three unimmunized Amish children who developed invasive Hib disease within 5 months were infected with rare ST45 strains only reported from Pennsylvania 15 years ago. While no epidemiologic link was found, patient 2 traveled to Indiana and Wisconsin prior to development of infection, raising the possibility of maintenance of this rare strain among Amish communities.

    Angela Myers, MD, MPH, FPIDS, Children's Mercy Hospital, Kansas City and University of Missouri-Kansas City School of Medicine, Kansas City, MO, Mary Anne Jackson, MD, FIDSA, FPIDS, Pediatrics, Children's Mercy Hospitals & Clinics and University of Missouri-Kansas City, Kansas City, MO, Lixin Zhang, PhD, Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, Douglas Swanson, MD, Children's Mercy Hospital & UMKC School of Medicine, Kansas City, MO and Janet Gilsdorf, MD, FIDSA, FPIDS, Pediatrics, University of Michigan Medical Center, Ann Arbor, MI

    Disclosures:

    A. Myers, None

    M. A. Jackson, None

    L. Zhang, None

    D. Swanson, Pfizer Inc: Grant Investigator , Research grant

    J. Gilsdorf, None

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