National trends in influenza mortality in Poland from 2009–2023 with regard to the periods before, during and after the COVID-19 pandemic

INTRODUCTION AND OBJECTIVE: In the 21st century two pandemics occurred, caused by viral respiratory infections. Both influenza and COVID-19 viruses exhibit high infectivity, have a rapid onset and mutate easily. Considering the fact that the influenza virus is characterized by rotational circulation of strains, while SARS-CoV-2 is constantly evolving, the difficulty is to effectively control the transmission. The extension of lifespan and the emergence of new diseases emphasize the need to assess the risk of death in endemic diseases. The aim of the study is determination of the scale and conditioning of mortality due to influenza in Poland in pre-Covid, Covid, and post-Covid years. MATERIAL AND METHODS: The study is a retrospective analysis of public statistics data concerning the causes of deaths. The data analyzed were obtained from the Central Statistical Office. RESULTS: In Poland during 2009 - 2023, 1,545 deaths due to influenza were registered, of which 875 in the pre-Covid period, and 670 during the Covid and post-Covid periods. During the COVID-19 pandemic the incidence of influenza significantly decreased. In Europe, in the season 2022-2023, a four-fold increase in the number of cases of influenza was recorded. In the assessed period of 15 years, the number of deaths among males slightly predominated over that among females, and more than doubled among the urban population, compared to the rural population. CONCLUSIONS: An increase in life expectancy and the growing threat of emerging diseases has important implications for public health. The national health policy strategy should prioritize and improve vaccination coverage, especially among groups at high risk.