Long-term impact of suboptimal rotavirus vaccines on acute gastroenteritis in hospitalized children in Northern Taiwan

Background/Purpose: Rotavirus vaccines were launched in Taiwan since early 2006. Our study was aimed to figure out long-term extended molecular epidemiology in acute gastroenteritis (AGE) in hospitalized young children after rotavirus vaccination in Taiwan. Methods: During the 10-year period from January 2007 to December 2016, fecal samples from children under 5 years old with AGE hospitalized in Chang Gung Children's Hospital (CGCH) were examined for enteric pathogens and they were divided into two time intervals: early post-vaccine (Jan.2007 to Dec.2011; EPV) and late post-vaccine (Jan.2012 to Dec.2016; LPV). Results: In total, 837 patients with AGE were enrolled with complete study. In the EPV period, 106 (26.7%) rotavirus and 65 (16.4%) norovirus infections were identified as major pathogens. In the LPV period, 79 (17.9%) rotavirus and 98 (22.2%) norovirus infections were diagnosed. Statistical analyses showed a significantly decreased prevalence of rotavirus infection (P = 0.002) and a significantly increased prevalence of norovirus (P = 0.034) and enteric bacterial infections (P < 0.001). A substantial decrease of rotavirus G1 (P = 0.079) in the LPV period and norovirus GII.4 prevailed through the decade. Conclusion: In Taiwan, under a suboptimal rotavirus vaccination policy, there was a marked decrease in the rate of rotavirus AGE of hospitalized young children. Significantly increased norovirus infection has replaced rotavirus as the leading cause. Expansion of rotavirus vaccine coverage, development of a norovirus prevention strategy, and sustained bacterial infection control are important for AGE containment in children in Taiwan. Copyright (C) 2017, Formosan Medical Association. Published by Elsevier Taiwan LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).