Measles in Poland in 2021.

Introduction: Measles is one of the most contagious childhood diseases, and the behavior also occurs in adults. This is a multi-year vaccination covered by an elimination program coordinated by the World Health Organization (WHO). Elimination of measles in the country is conditional on a 95% incidence of infection with two victims, monitoring the epidemiological situation, registering all suspected cases of measles, and monitoring by the WHO Reference Laboratory. In our country, the Department of Virology of the NIZP PZH-PIB in Warsaw serves as the head of the Department of Virology.

Objectives: The aim of this study was to evaluate epidemiological indicators of measles in Poland in 2021 compared to previous years, taking into account the impact of the COVID-19 pandemic.

Material And Methods: The assessment of the epidemiological situation was based on a review of data from the bulletin, "Infectious Diseases and Poisons in Poland in 2021" (5), and the assessment of the immunization status of the population was based on data from the bulletin, "Immunization in Poland in 2021" (6). Classification of cases was made based on the definition used in the 2021 surveillance (7). Data from the epidemiological surveillance system "EpiBase" were also used.

Results: In 2021, 13 measles cases were registered in Poland (incidence 0.03 per 100,000), 44.8% less than in 2020 and 80% less than the median in 2014-2018. In 2021, the highest incidence was recorded at 0.32 per 100,000 children aged 0-4 years. 6 patients (46.2%) were hospitalized; no deaths due to measles were reported. 32 suspected measles cases were recorded, with over a hundred cases expected. Vaccination status of children aged 3 with the first dose was 90.8%, and the second dose was given to children at the age of 9. - 84.6%.

Conclusions: Epidemiological indicators of measles in 2021 in Poland compared to 2020 have decreased. A similar trend observed throughout Europe. This is related to the extinguishment of outbreaks that occurred before the pandemic, mainly in 2019.