Dependence of Lyme disease incidence in children on environmental factors in Wielkopolska Province (West-Central Poland).

Lyme borreliosis (LB) causes hundreds of thousands of new human infections worldwide annually. This is the first study connecting the LB risk to children with environmental factors. The potential impacts were assessed of environmental factors (deer density in forests, coverage of potential broadleaved forest plant communities, urbanization index) on the number of LB cases in children. Analysis covered the medical records of 196 children diagnosed with LB (ICD- A69.2) from 1 January 2012 - 30 October 2021 in Wielkopolska Province (Poland). All examined factors were positively correlated with LB cases. The highest correlation with the number of patients diagnosed with LB was presented by the degree of urbanization (percentage of the population living in cities in the total inhabitants of the study region). The number of cases was much higher in the second research period (2017-2021). The number of LB cases in children is increasing as the coverage of potential broadleaved forest plant communities increases. The number of cases among males is positively correlated with the coverage. Deer density is positively correlated with the number of LB cases among children - the higher the deer density, the greater the risk of LB infection. LB cases in children are positively correlated with the urbanization index - the more people that live in cities, the greater the risk to children of LB infection.