Cases of Crimean-Congo haemorrhagic fever in North Macedonia, July to August 2023

Tick-borne diseases at the crossroads of the Middle East and central Europe

OBJECTIVES

The Balkan Peninsula, acting as a crossroad between central Europe and the Middle East, presents diverse ecosystems supporting various tick species capable of transmitting TBDs. This study focuses on Serbia and North Macedonia, both endemic for TBDs, aiming to investigate human-biting ticks' prevalence, TBD prevalence, and major TBPs in blood samples.

PATIENTS AND METHODS

This prospective observational study was conducted in 2022 at two medical centers, involving 45 patients from Novi Sad, Serbia, and 17 patients from Skopje, North Macedonia. All participants had either a tick still attached or had had one removed within the preceding 48 h. The study consisted in clinical evaluations of patients and testing of patient samples and ticks for tick-borne pathogens using a High-Throughput pathogen detection system based on microfluidic real-time PCR. In addition, the study assessed the genetic diversity of the identified pathogens.

RESULTS

Ixodes ricinus was the most prevalent tick species, with varying infestation rates across various body parts. Tick species and feeding times differed between Novi Sad and Skopje. TBPs were prevalent, with Rickettsia spp. dominant in Skopje and a mix including Rickettsia aeschlimannii, Rickettsia monacensis, Anaplasma phagocytophilum, and Borrelia afzelii in Novi Sad. Subclinical bacteremia occurred in 8.06% of cases, mostly involving Anaplasma spp. Clinical manifestations, primarily local hypersensitivity reactions, were observed in six patients. Phylogenetic analysis confirmed R. aeschlimannii and R. monacensis identity, highlighting genetic differences in gltA gene sequences.

CONCLUSIONS

This study sheds light on the prevalence and diversity of TBPs in tick-infested individuals from Serbia and North Macedonia, contributing valuable insights into the epidemiology of TBDs in the Balkan region.

Ixodid ticks and zoonotic tick-borne pathogens of the Western Balkans

Ixodid ticks are distributed across all countries of the Western Balkans, with a high diversity of species. Many of these species serve as vectors of pathogens of veterinary and medical importance. Given the scattered data from Western Balkan countries, we have conducted a comprehensive review of available literature, including some historical data, with the aim to compile information about all recorded tick species and associated zoonotic pathogens in this region. Based on the collected data, the tick fauna of the Western Balkans encompasses 32 tick species belonging to five genera: Ixodes, Haemaphysalis, Dermacentor, Rhipicephalus and Hyalomma. A range of pathogens responsible for human diseases has also been documented, including viruses, bacteria and parasites. In this review, we emphasize the necessity for integrated surveillance and reporting, urging authorities to foster research by providing financial support. Additionally, international and interdisciplinary collaborations should be encouraged that include the exchange of expertise, experiences and resources. The present collaborative effort can effectively address gaps in our knowledge of ticks and tick-borne diseases.

Current Status and Challenges Associated with Tick-Borne Pathogens and Diseases: Where Do We Stand?

Lyme Borreliosis (LB), caused by Borrelia burgdorferi sensu lato (s [...].