Rotavirus gastroenteritis in children hospitalized in northeastern Poland in 2006-2020: severity, seasonal trends, and impact of immunization.

Toczylowski, Kacper; Jackowska, Katarzyna; Lewandowski, Dawid; Kurylonek, Sandra; Waszkiewicz-Stojda, Marlena; Sulik, Artur

OBJECTIVES The introduction of the rotavirus vaccine in 2006 significantly reduced the incidence of acute gastroenteritis (AGE) in childhood. In Poland, the rotavirus vaccine was included in the national immunization program in 2021. The aim of this study was to summarize the epidemiology of AGE in northeastern Poland before 2021 and to evaluate the effectiveness of out-of-pocket rotavirus vaccinations on the incidence of rotavirus AGE. METHODS A review of patients with gastroenteritis hospitalized between 2006 and 2020 in northeastern Poland, with regards to the coverage with the rotavirus vaccine in the region. RESULTS Rotavirus was the most common agent of gastroenteritis. The seasonality of rotavirus gastroenteritis peaked between February and May, except in 2020. The COVID-19 pandemic has skewed any viable comparisons of seasonality. Coverage with the rotavirus vaccine did not exceed 25% during the study period and had no impact on the number of hospitalizations. CONCLUSIONS Rotavirus was the major causative agent of AGE in northeastern Poland. Voluntary vaccines did not affect the number of hospitalizations due to rotavirus AGE. Our data suggest that universal immunization is a key to achieve a significant reduction of rotavirus associated diarrhea.