How the epidemiology of rotavirus infections is changing with vaccination in the Czech Republic.

Aim: To describe the epidemiological situation of rotavirus gastroenteritis (RVGE) and the impact of vaccination on hospitalization for RVGE in the Czech Republic in 2018-2023.

Methods: A descriptive analysis was performed of anonymized RVGE cases reported under code A08.0 to the Infectious Diseases Reporting System (ISIN) in the Czech Republic in 2018-2023. The Chi-square test was used to analyse binary variables. The effect of vaccination on hospitalization was assessed using logistic regression with odds ratio (OR) and 95% confidence interval. Excel, STATA, and Datawrapper GmbH programs were used. The incidence of the disease was calculated per 100,000 population.

Results: In the monitored period, a total of 26,303 RVGE cases were reported in the Czech Republic (range 1,811-7,483 per year), which corresponds to an average annual incidence of 41.0 (range 16.9-69.6) per 100,000 population. Fifty-one percent of cases occurred in women. The average annual sex-specific incidence rates were comparable. Patients were aged 0-101 years (median 3 years, interquartile range [IQR] 1-8 years). The maximum numbers of cases were recorded in the months of March to June. In the pandemic years 2020 and 2021, the overall numbers of cases were lower, and therefore the seasonality was less expressed. The average annual specific incidence was highest in the Vysočina, South Bohemian and Olomouc Regions. A total of 18,693 (71.1%) cases of RVGE were hospitalized, most of them in the age groups 1-4 years (34.7%) and 5-9 years (11.9%). Vaccination data were available for 21,142 individuals with RVGE, of whom 304 (1.4%) were reported as vaccinated. The risk of hospitalization for RVGE was statistically significantly lower (p < 0.001) in vaccinated than in unvaccinated individuals. A total of 27 RVGE outbreaks were reported, with the largest one involving 152 cases. Two hundred and twenty-six cases were classified as imported.

Conclusions: After the introduction of RVGE vaccination in the Czech Republic, a reduction in RVGE cases, hospitalizations, and deaths was expected. However, a significant impact of vaccination on the RVGE burden has not yet been observed in the country. The main reason continues to be low RVGE vaccine coverage. We therefore recommend including this voluntary vaccination in the schedule covered by health insurance and also call for early communication of the appropriateness of such vaccination between the paediatric/adolescent medicine practitioners and children's parents.