Lyme disease in Poland in 2020

INTRODUCTION. Lyme borreliosis, also known as Lyme disease, is a zoonotic disease transmitted by ticks. 
The infection occurs through a bite by a common tick (Ixodes ricinus). Due to the annual cycle of tick activity, mainly dependent on temperature, Lyme disease is seasonal. In certain cases, post-exposure prophylaxis may be indicated, while the vaccine is in phase III clinical trials.
AIM OF THE STUDY. The aim of the study is to assess the epidemiological situation of Lyme disease in Poland in 2020 compared to the situation in previous years.
MATERIAL AND METHODS. The epidemiological situation of Lyme disease in Poland was assessed on the basis of the data sent to NIPH NIH – NRI by voivodeship sanitary-epidemiological stations and published in the bulletin “Infectious diseases and poisoning in Poland in 2020”.
RESULTS. In 2020, 12,934 Lyme borreliosis cases and 459 hospitalizations were registered which, compared to 2019, means a 37.3% decrease in morbidity and a 73% decrease in hospitalization. It may be related to the outbreak of the SARS-CoV-2 virus at the end of 2019, which reached Poland at the beginning of March 2020. It can be seen that in Q2, due to the lower activity of people due to the epidemic, the number of cases of Lyme disease was less than in Q1 (2,064 in Q2 compared to 2,253 in Q1). The decrease compared to 2019 also continued in the third and fourth quarter, by 28% and 49%, respectively.
SUMMARY AND CONCLUSION. The impact of the SARS-CoV-2 outbreak on the distribution of Lyme disease incidence is noticeable, in particular on the decrease in the overall number of cases during the year, as well as on hospitalization due to Lyme disease with the previously observed stabilization of the incidence.
The pandemic could have influenced this state of affairs on various levels. The main reason was, of course, the introduction of the epidemic and the related restrictions (including reduced mobility), but it cannot be ruled out that the cause was not an excessive burden on the health care system and sanitary inspection (delay in registration of reports).