LB-18. Burden of Rotavirus Infections in the Province of Quebec (Canada) prior to the Implementation of a Publicly-Funded Vaccination Program
Session: Poster Abstract Session: Late Breaker Posters
Saturday, October 22, 2011
Room: Poster Hall B1
  • Burden of Rotavirus Infections.pdf (385.1 kB)
  • Background:  

    Rotavirus (RV) is the leading cause of severe gastroenteritis (GE) in young children. RV vaccination programs (VP) have been implemented in various countries since 2006. In Canada, in the absence of a publicly funded VP, the uptake has remained low (15%). The province of Quebec (Canada) will implement a publicly funded RV VP in November 2011. To assess the impact of this VP, we aimed to evaluate trends in RV infection from 2006-2011.


    Retrospective review of RV ELISA testing from the Montreal Children's Hospital (MCH) from July 2006 to June 2011 to evaluate RV season timing and peak activity. The MCH is a 140-bed teaching hospital that serves approximately 50% of Montreal’s pediatric population (birth cohort 23,000), with over 75,000 visits to its Emergency Department; over 3,000 of which are for GE .  We used a five-week moving average given our sample size and intrinsic variability to follow the proportion of positive RV ELISA over time. A season was defined to start with the first 2 consecutive weeks and end with the last 2 consecutive weeks when the percentage (%) of specimens testing positive for RV was ≥ 10%. The peak of the season was defined as the week with the largest % of specimens that tested positive for RV.  Duplicate tests (ordered within 48 hours of previous tests) were excluded.


    Of 3008 RV detection tests performed between July 2006 and June 2011, 183 were duplicates. Of the remaining 2825, 329 were positive by ELISA (13.4%). Whereas the 2006, 2007, 2008 and 2009 seasons demonstrated bimodal distribution with staggered onsets and similar peaks, the 2009-2010 season had a trimodal distribution, with shorter seasons of lesser intensity. During the 2010-2011 season, there was only one RV season with shorter duration and weaker intensity than the longest of the bimodal distributions seen in  2006-2009 (16 weeks vs 21-28 weeks, and 24.7% vs 31.1-32.1% respectively). 


    During the 2009 and 2010 seasons, the pattern of RV infectivity changed compared to the 2006-2008 seasons. In the United States, the substantial decrease in RV activity during the 2009-2010 season was attributed to the benefits of the national RV VP. However, in the absence of a similar Canadian campaign, our data suggest that other factors contributed to this decline.

    Subject Category: P. Pediatric and perinatal infections

    Estelle Chetrit, B.Sc. MD-MBA Candidate, Pediatrics, McGill University, Montreal, QC, Canada and Caroline Quach, MD MSc FRCPC, Pediatric Infectious Diseases and Medical Microbiology, The Montreal Children's Hospital, McGill University, Montreal, QC, Canada


    E. Chetrit, None

    C. Quach, None

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