Hyalomma marginatum is a prominent tick vector responsible for transmitting various pathogens, including the Crimean-Congo hemorrhagic fever virus (CCHFV), across Europe. This systematic review consolidates findings from 144 publications regarding the geographical distribution of H. marginatum and its associated pathogens. Significant populations have been identified primarily in Southern Europe and Balkan Peninsula, indicating a concerning trend. Additionally, climate change and migratory bird movements may facilitate its further dispersal, potentially leading to the establishment of H. marginatum in transalpine regions. Consequently, robust monitoring and surveillance strategies are essential to mitigate the public health and livestock threats posed by Hyalomma-borne diseases. Raising awareness and implementing preventive measures will be crucial in addressing the challenges associated with this tick vector.

• Keywords
• Crimean–Congo hemorrhagic fever virus, Hyalomma marginatum, Rickettsia, migratory birds, surveillance, tick distribution,
• MeSH
• Arachnid Vectors * virology   physiology   MeSH
• Ixodidae * virology   physiology   MeSH
• Animal Distribution MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Systematic Review MeSH
• Geographicals
• Europe epidemiology   MeSH

Birds are long-known as important disseminators of ixodid ticks, in which context mostly their latitudinal, south-to-north migration is considered. However, several bird species that occur in the eastern part of the northern Palaearctic are known to migrate westward. In this study, a female tick collected from the sedge warbler, Acrocephalus schoenobaenus, in Lithuania was identified morphologically and analyzed with molecular-phylogenetic methods. In addition, literature data were reviewed on ixodid tick species known to be associated with birds that have recorded east-to-west migratory route in the Palaearctic. The tick collected from A. schoenobaenus was morphologically identified as Ixodes apronophorus. Two mitochondrial genetic markers for this specimen showed 100% identity with a conspecific tick reported previously in Western Siberia, Russia. Based on literature data, as many as 82 bird species from 11 orders were found to have records of ringing in the easternmost part of the northern Palaearctic and recaptures in Europe. Of these bird species, 31 ixodid tick species were reported in the Euro-Siberian region. Nearly all passeriform bird species with east-to-west migration were reported to carry ticks, whereas no reports of tick infestation were documented from the majority of wetland-associated bird species, mostly from the orders Anseriformes and Charadriiformes. The first European sequences of bona fide I. apronophorus revealed genetic connectedness with conspecific ticks reported from Siberia. Since the principal hosts of this tick species are rodents which do not migrate large distances, the most likely explanation for genetic similarity in this direction is dispersal of this tick species via migratory birds. Given the high number of tick species that are known to associate with bird species migrating in westward direction, this appears to be an important means of the gene flow between geographically distant tick populations in the northern Palaearctic.

• Keywords
• 16S rRNA gene, Acrocephalus, Bird migration, Ixodidae, Passeriformes, cox1 gene,
• Publication type
• Journal Article MeSH