The changes of the epidemiology and clinical characteristics of rotavirus gastroenteritis-associated convulsion after the introduction of rotavirus vaccine.

Rotavirus (RV) vaccine contributed to the reduction of the hospitalization for gastroenteritis (GE)-associated convulsion whereas there were few studies investigating the vaccination rate and the reduction of the disease simultaneously. The aim of this study is to investigate the alterations of the epidemiology and clinical characteristics of RVGE-associated convulsion after the introduction of RV vaccines and evaluate the reduction of the disease in the context of the vaccination rate. This retrospective study included hospitalized patients with GE and GE-associated convulsion from 2009 to 2015. The proportion of patients with RVGE and RVGE-associated convulsion and the clinical characteristics of RVGE-associated convulsion were compared between the pre- (2009-2011) and post-vaccination periods (2013-2015). The presumptive RV vaccination rate in the subject area was also investigated. During the pre- and post-vaccination periods, 47 and 49 patients with GE-associated convulsion, and 319 and 330 with GE were enrolled, respectively. Proportions of both hospitalized patients with RVGE-associated convulsion and those with RVGE during the post-vaccination period were significantly lower than those during the pre-vaccination periods (P = 0.042 and P = 0.003). Serum sodium level was significantly lower in hospitalized patients with RVGE-associated convulsion during the post-vaccination period (P = 0.021). The presumptive RV vaccination rates were 35.9%, 45.8% and 52.6% in 2013, 2014 and 2015, respectively. The proportions of hospitalized patients with RVGE-associated convulsion as well as those with RVGE decreased after the introduction of RV vaccine. RV vaccination would be also effective for the prevention of extra-intestinal complications of the virus.