Background

Hepatitis A is a fecal-oral infection linked to socioeconomic conditions. In low-endemicity settings, many adults are susceptible, increasing outbreak risks.

Objectives

The aim of the study was to assess the epidemiological situation of hepatitis A and vaccination coverage in Poland from 2015 to early 2026.

Material and methods

A retrospective descriptive study was conducted using aggregated surveil-lance data from the National Institute of Public Health (NIPH NIH-NRI) for 2015–2024. Data included case numbers, incidence rates, and socio-demographic characteristics (age, gender, place of residence, and month of onset) across all age groups, including children and adults. Cases were defined according to the European Commission definition (Decision 2012/506/EU). Vaccination coverage was assessed for 2019–2023 using national vaccination reports and population data. Additionally, more recent data from 2025 and the first quarter of 2026 were included for selected indicators.

Results

Hepatitis A incidence increased markedly during the 2017 epidemic (3,006 cases; incidence: 7.82 per 100,000), declined to 92 cases in 2021, and has risen again since 2022, with further in-creases in 2025 (1,085 cases; incidence: 2.9) and early 2026 (628 cases in Q1). A clear seasonal pattern was observed, with peaks in autumn. Initially, most cases occurred in men and adults aged 25–39 years; over time, differences by gender diminished, with a relative increase in younger age groups. Urban populations predominated, although the urban–rural gap narrowed. Vaccination coverage remained very low (0.07–0.20% population).

Conclusions

A resurgence of hepatitis A has been observed in Poland since 2022. High hospitalization rates and adult predominance indicate a substantial burden in a susceptible population. Strengthened surveillance and targeted vaccination are needed.