141. Breakthrough Rotavirus (RV) infections in vaccinated children during 2011 season in Detroit
Session: Poster Abstract Session: Adult and Pediatric Vaccines
Thursday, October 3, 2013
Room: The Moscone Center: Poster Hall C
Posters
  • FINAL RV_Poster_2013.pdf (1.0 MB)
  • Background:

    We have noted an increase in the number of children treated for RV infections at Children’s Hospital of Michigan, Detroit during the 2011 season including some who were RV vaccine recipients. The purpose of the study is to identify the circulating RV genotypes during 2011 season and compare the genotypes affecting the RV-immunized and non-immunized children. 

    Methods:

    Rotavirus RNA was extracted from RV EIA-positive stool samples and genotyped for VP7 (G-type) and VP4 (P-type) genes by reverse transcription (RT) and multiplex PCR using different specific primers. Vaccination status was reviewed using Michigan Care Improvement Registry (MICR).

    Results:

    RV EIA positive samples were 49 in 2010, 238 in 2011 and 13 in 2012.  MICR data were available for 131 children seen during 2011 RV season: 31 (24%) had received at least 1 dose of RV vaccine (RV5 or RV1).  The age range of children was 8 d to 70 mo (mean 24.4mo, median 16mo), 51% were boys. Stool samples were available for genotyping on 18 vaccinated children and were compared to a cohort of 50 unvaccinated children that were randomly selected throughout RV season and temporally associated with the samples of vaccinated children.  The 68 stool samples were genotyped. G1 was the predominant G genotype (58.8%) followed by G9 (17.7%) and G4 (15.5%). P[8] was the predominant VP4 type (68%) followed by P[6] (17.6%) and P[4] (3%). All 12 G9 strains were associated with P[6]. The most prevalent G-P combination was G1P[8] (56%), followed by G9P[6] (17.6%).  Thirteen patients were infected with 2 G-types and 8 with 2 P-types.  Of the 18 vaccinated children, 8 received 3 doses of RV vaccines (6 received RV5; 2 received 2 RV5 and 1 RV1 doses), 4 received 2 doses of RV5 and 6 received one dose of RV5.  The most common genotype among vaccinated children was G1P[8] (67%) which is included in RV vaccines.  There was no difference in the G or P genotype proportions between the two groups (vaccinated and un-vaccinated) (p> 0.05). 

    Conclusion:

    Breakthrough infections in RV-vaccinated children were due to strains that were circulating in our community during the 2011 RV season and were not different from those recovered from non-vaccinated children. The presence of G9P[6] strains, not covered by RV vaccines, during this study period underscores the need to monitor circulating RV strains in our area.

    Nahed Abdel-Haq, MD1, Muhammad Amjad, PhD2, Eric McGrath, MD1, Hossein Salimnia, PhD3 and Basim Asmar, MD4, (1)Children's Hospital of Michigan, Wayne State University, Detroit, MI, (2)Department of Clinical Laboratory Sciences, Marshall University, Huntington, WV, (3)Detroit Medical Center/Wayne State University, Detroit, MI, (4)Pediatrics/ Pediatric Infectious Diseases, Children's Hospital of Michigan, Wayne State University, Detroit, MI

    Disclosures:

    N. Abdel-Haq, None

    M. Amjad, None

    E. McGrath, None

    H. Salimnia, None

    B. Asmar, None

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