PREVALENCE AND SURVEILLANCE OF LYME BORELIOSIS IN ISTRIA, CROATIA

Abstract

Climate change is the main cause of global warming, which significantly affects human health, among other things, due to the spread of tick-borne pathogens. The paper presents a spatial analysis of collected ticks (from 2020 to 2023), historical data on the prevalence of Lyme boreliosis (LB) in humans (from 2016 to 2023), and the prevalence of the causative agent of LB, bacterias from the genus Borrelia sp. extracted from ticks. Pathogenic spirochetes of the Borrelia burgdorferi s.l. complex is transmitted by ticks of the genus Ixodes, and in the territory of Istria, three vector species for this pathogen stand out: Ixodes ricinus (70.72%), Ixodes hexagonus (0.13%) and Ixodes frontalis (1.40 %). In the observed period, a total of 115 cases of borreliosis were recorded in the examined period. The largest number of human cases of LB are recorded in urban areas. Most ticks are collected in urban areas from dogs, which are sentinel animals for human borreliosis. After proving the presence of Borrelia sp. by molecular analyses from ticks, by qPCR method, all obtained data were entered into the QGIS database to monitor the areas of greater infestation of Borrelia-infected ticks. The goal of the research is to collect data on the distribution of tick species in Istria and to investigate their role in the transmission of bacteria from the Borrelia burgdorferi s. l. complex. Scientific contribution of this research is the monitoring of ticks and the presence of LB in Istria, the identification of habitats with higher infestations, and creation of the first systematic database on tick-borne diseases in Croatia. The use of GIS technologies significantly contributes to disease surveillance.