Lyme disease in Poland in 2024

Background Lyme disease, caused by Borrelia burgdorferi sensu lato spirochetes, is the most common tick-borne infectious disease in Europe. The condition is characterised by a varied clinical course and diagnostic challenges, particularly during the early stage of infection. The rising number of cases underscores the need for effective prevention. Objective The aim of this study is to discuss the epidemiological situation of Lyme disease in Poland in 2024 compared to previous years. Material and methods To assess the epidemiological situation of Lyme disease in Poland, data submitted to the National Institute of Public Health, National Institute of Hygiene – National Research Institute by the Voivodeship Sanitary and Epidemiological Stations and published in the annual bulletin: "Infectious diseases and poisonings in Poland in 2024" were used. Results In 2024, 29,897 cases of Lyme disease were recorded, corresponding to an incidence rate of 79.6 per 100,000 population, with 1,072 hospitalisations due to the disease. Cases and the incidence rate increased by 18.2% and 18.6%, respectively, compared with the previous year. A seasonal pattern in the occurrence of borreliosis is evident across the quarters: the number of cases rose from 2,218 in Q1 to 13,449 in Q3, before falling to 7,263 in Q4. The highest incidence rates were recorded in the Podlaskie (134.2 per 100,000 population), Małopolskie (132 per 100,000 population), and Warmińsko-Mazurskie (108.6 per 100,000 population) voivodeships. Conclusions The number of Lyme disease cases reported in 2024 was higher than in the previous year and exceeded the levels recorded in Poland prior to the COVID-19 pandemic. Although neuroborreliosis accounted for only 1.4% of all Lyme disease cases, it was responsible for 36.7% of all cases of bacterial meningitis and/or encephalitis in 2024. The seasonality of Lyme disease remained consistent, with a peak in incidence during the third quarter (Q3) and a decline in the fourth quarter (Q4). As in previous years, the eastern part of Poland, specifically the Podlaskie, Małopolskie, and Warmińsko-Mazurskie voivodeships, recorded the highest incidence rates.