626. Modest Vaccine Coverage and Continuing Fluctuations in Genotypes but no Consistent Fall in Rotavirus Diarrhoea in an Emergency Facility in Portugal
Session: Poster Abstract Session: Pediatric Vaccines
Friday, October 21, 2011
Room: Poster Hall B1
Background: Although not yet a national recommendation, Rotavirus (RV) vaccines are provided via private practice in Portugal, with estimated coverage slowly rising (15 to 42%, from 2007-10; Rotateq® and Rotarix® ~50/50%, currently 31% in Coimbra district). To identify trends we have been conducting annual wintertime surveillance of children presenting to our emergency service (ES) in Coimbra.

Methods: During 5 epidemic seasons (January-June; 2006-10), children <3Y attending the ES with acute gastroenteritis (AG) had available stool samples tested for RV (VIKIA®). Positive samples were genotyped.

Results: A total of 5983 AG cases (ICD-9 0093) were seen: 1953 (33%) had available stool samples (range: 29% (2008)-37% (2009)) and 711 (36%) were positive. The proportion of RVAG fluctuated between seasons (49%, 39%, 24%, 25% and 40% respectively) as did the frequency of co-circulating RV genotypes. G9P[8] the most frequent in 2006 (~90%) dropped to 26% (2007), 2% (2008), 6% (2009) and went up again to 54% in 2010. G1P[8] increased progressively to become the predominant type in 2009 (65%) and dropped to second in 2010 (42%). G3P[8], predominant in 2008 (40%) was undetected in 2009 and found in <1% of cases in 2010. G2P[4] undetected in 2006, was found in a significant proportion of cases in 2007 (25%) and 2008 (30%) and in very low proportions in 2009-10. G4 P[8], detected for the first time in 2009 (20%), disappeared in 2010. There were no consistent changes in seasonality or proportion of cases admitted. There is a suggestion of a modest rise in peak age at presentation in 2010 which may or may not be sustained.

Conclusion: Within design constraints, we demonstrate fluctuations in RVAG but no progressive trends in numbers to date, in our region. Large and, so far, unpredictable genotype changes from year to year are seen. Changes in epidemic seasonal shape do not conform to simple “delay”. It appears that higher and sustained vaccine coverage is needed for the clear and impressive impact on disease reported from other countries. Future community & hospital-based studies, focusing on local vaccine coverage, are planned.


Subject Category: I. Adult and Pediatric Vaccines

Fernanda Rodrigues, MD1, Miren Iturriza, PhD2, Luís Januário, MD1 and Adam Finn, MD, PhD3, (1)Emergency Service & Infectious Diseases Unit, Hospital Pediátrico de Coimbra, Coimbra, Portugal, (2)Vírus Reference Department,, Health Protection Agency, London, United Kingdom, (3)School of Clinical Sciences, University of Bristol, Bristol, United Kingdom

Disclosures:

F. Rodrigues, SPMSD: Scientific Advisor, Educational support, Research support and Speaker honorarium
GSK: Scientific Advisor, Educational support and Speaker honorarium

M. Iturriza, SPMSD: Investigator, Educational support and Research support
GSK: Investigator, Educational support and Research support

L. Januário, SPMSD: Educational support, Educational support
GSK: Educational support, Educational support

A. Finn, SPMSD: Scientific Advisor, Consulting fee, Educational support and Speaker honorarium
GSK: Grant Investigator and Scientific Advisor, Consulting fee, Educational support, Research grant, Research support and Speaker honorarium

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