Non-zoonotic tick-borne pathogens in Western Balkan

Abstract

Ixodid ticks are present throughout the Western Balkan countries, including Albania, Bosnia and Herzegovina, Croatia, Montenegro, North Macedonia and Serbia, with many species serving as vectors for pathogens of both veterinary and medical importance. We have conducted a thorough examination of existing literature, encompassing historical documents, to collect information on all documented non-zoonotic tick-borne pathogens found in ticks, pets, farm animals and wild animals across the Western Balkan region. A comprehensive review was necessary due to the scarcity and scattered nature of available data from this area. The tick fauna in the Western Balkans consists of 32 species across five genera: Ixodes, Haemaphysalis, Dermacentor, Rhipicephalus and Hyalomma. Various pathogens responsible for diseases in animals, including bacteria and parasites, have also been documented, many of which can cause important diseases and significant reductions in animal productivity. Initial efforts were directed towards pathogen surveillance and the characterisation of non-zoonotic tick-borne pathogens, resulting in the identification of Theileria orientalis, Anaplasma bovis and Anaplasma marginale in cattle, although significant gaps remain in the current research. Studies on small ruminants have been sparse, with confirmed cases of Anaplasma ovis and Babesia ovis in sheep, but no comprehensive and systematic research on pathogens in goats. In contrast, research on canine piroplasms has identified several species, including Babesia canis and Babesia vulpes. Studies on wild animals, however, have predominantly focused on wild canines and carnivores, with limited attention given to non-zoonotic pathogens. Notably, only one study has reported non-zoonotic tick-borne pathogens in artiodactyl species and wild felids. This review is a much needed overview of existing research on non-zoonotic tick-borne diseases in the Western Balkans, including the historical context, current data and research gaps. Given the significant impact of these diseases on animal health and productivity, as well as their potential biodiversity, further comprehensive studies and the establishment of national surveillance systems for tick-borne diseases are essential for a better understanding and mitigation of their impact.