Norovirus-driven gastroenteritis in Quebec more common after start of rotavirus vaccine
After Quebec initiated a rotavirus vaccination program in 2011, norovirus became more prevalent than rotavirus in cases of pediatric gastroenteritis, according to findings published in The Pediatric Infectious Disease Journal.
“It was important to document the impact of the publicly funded rotavirus vaccination program, in particular to ensure that no replacement by new gastroenteritis pathogens occurred,” Caroline Quach, MD, MSc, co-director of the Vaccine Study Centre at McGill University Health Centre, told Infectious Diseases in Children. “Although we have seen an increase in the proportion of cases of gastroenteritis caused by norovirus over the study period, it was reassuring to see that the severity of these infections was less than rotavirus.”
Before the vaccination program, up to one in 85 children with rotavirus visited an ED annually in Canada, Quach and colleagues wrote. In the United States and Finland, rotavirus vaccine programs resulted in norovirus becoming the leading cause of pediatric medically attended gastroenteritis, with one in 14 children in the U.S. requiring emergency care by age 5 years. In November 2011, Quebec province began a rotavirus vaccination program. After implementation, the researchers sought to compare rotavirus with norovirus in terms of clinical severity regarding pediatric gastroenteritis cases resulting from each disease.
From 2012 to 2014, surveillance for acute gastroenteritis began among 705 children aged 8 weeks to younger than 3 years. Along with assessing patient demographics and clinical histories, the researchers tested patient stool samples for rotavirus, norovirus and sapovirus. To determine the severity of each disease, they compared the differences of several clinical outcomes after adjusting for age.
Across the study, the researchers found that 20.4% (95% CI, 16.5%-24.3%) of patients tested positive for rotavirus, and 25.5% (95% CI, 21.3%-29.8%) had norovirus. From June 2012 to May 2013, rotavirus and norovirus prevalence were similar, but from June 2013 to May 2014, rotavirus prevalence was 21.4% (95% CI, 14.3%-28.5%) lower than norovirus.
While norovirus was more prevalent, the investigators wrote, rotavirus was more severe, with patients more likely being febrile, dehydrated, hospitalized and reporting more diarrheal episodes.
“An apparent reduction in the relative prevalence of rotavirus-associated gastroenteritis is not surprising, given the effectiveness of the Rotarix vaccine (GlaxoSmithKline) and the success of childhood rotavirus vaccination programs in reducing the burden of pediatric rotavirus gastroenteritis in the U.S. and elsewhere,” Quach and colleagues wrote. – by Will Offit
Disclosure: The researchers report no relevant financial disclosures.