Search Results (227)

Hard ticks (Acari: Ixodidae) are vectors of numerous pathogenic microorganisms in humans and animals. In Croatia, very few studies have been conducted on the diversity of hard tick fauna in urban green areas. Therefore, the aim of this study was to investigate the diversity and seasonal dynamics of hard tick fauna in three eastern Croatian cities. Three species of ticks were recorded in Osijek and Vukovar, while six species were recorded in the area of the city of Vinkovci. In total, six species were collected during this study, and together with an earlier record of Ixodes canisuga, seven species are now known from urban green habitats in this region. The most abundant species was I. ricinus (82.06%), followed by R. sanguineus s.l. (9.03%), H. concinna (6.51%), D. reticulatus (1.26%), I. hexagonus (0.91%), D. marginatus (0.11%), and I. canisuga (0.11%). The detection of R. sanguineus s.l. in Vinkovci and Vukovar represents the first record of this species in eastern Croatia. In Osijek and Vinkovci, I. ricinus was the most abundant species. This tick is the primary vector of Lyme disease and tick-borne encephalitis, the two most common tick-borne diseases affecting humans in eastern Croatia. In Osijek and Vukovar, peak abundance of ticks was recorded in May, while in Vinkovci in March. Given that the species documented here represent 30.43% of all tick species recorded in Croatia, their presence in urban areas highlights the potential public health risk associated with ticks in these environments. Full article

Due to the evident increase in tick-borne diseases worldwide, it is necessary to constantly update information on the distribution and zoonotic potential of hard ticks. We studied diversity, population structure, and seasonal dynamics of hard tick fauna, faunal similarity and the climate impact on tick occurrence in natural habitats (NHs) (forest communities) and anthropogenic habitats (AHs) (orchards, grasslands, degraded forests) in eastern and central parts of Continental Croatia. Host-seeking hard ticks were sampled by the flag-dragging method in lowland AHs (Bansko Hill (BH); 2023–2024 yr.) and in mountainous NHs (Medvednica Mountain (MM); 2019–2021, 2024 yr.). Overall, 2726 specimens belonging to eight hard tick species (Ixodes ricinus, I. frontalis, I. hexagonus, I. kaiseri, Haemaphysalis inermis, H. concinna, Dermacentor marginatus, D. reticulatus) were identified in AHs, while in NHs 1543 hard ticks, belonging to three species (I. ricinus, I. frontalis, D. reticulatus), were collected. The most abundant species in both habitat types (47.83% in AHs, 99.80% in NHs) was I. ricinus, showing unimodal seasonal activity within studied NHs and bimodal activity at AHs. Comparison of hard tick fauna in different habitats using the Sørenson index on BH and MM showed a high percentage of similarity (50.0–88.8). At AHs, a significant (p < 0.05) negative correlation was determined between the abundance (N) and the mean monthly air temperatures (°C) for H. inermis (r = −0.5931; p = 0.0421) and D. reticulatus (r = −0.6289; p = 0.0285), while their numbers positively correlated (r = 0.5551; p = −0.2667; r = 0.4430; p = 0.1492) with air humidity (%). In contrast, the number of sampled host-seeking I. ricinus ticks at natural forest habitats on MM was positively associated with air temperature and negatively with air humidity at elevations from 200 to 1000 m a.s.l. (r = −0.7684; p = 0.0259; at 200 m a.s.l.). Collected specimens of I. frontalis mark the first record for Osijek–Baranja County, while the sampled D. reticulatus on MM represents the first catch at 1000 m a.s.l. in Croatia. This new data on the distribution and seasonality of medically important hard tick species in Continental Croatia contributes to identifying tick-risk foci and high-risk periods. Full article

Ticks are important parasites of economic and public health because of their ability to transmit zoonotic diseases. Tick-borne encephalitis virus (TBEV), now officially Orthoflavivirus encephalitidis, is a Flavivirus with five main subtypes of which three, the European (TBEV-EU), the Siberian (TBEV-Sib), and the Far-Eastern subtypes (TBEV-FE), are supposedly circulate in Latvia. Several hard tick species are involved in TBEV circulation and transmission in nature. This study set out to describe the genetic landscape of TBEV subtypes in Latvian tick populations. In 2019 and 2021 to 2023, a total of 3026 ticks were collected in three Latvian regions, with Ixodes ricinus as the dominant species (2822 specimens), followed by Ixodes persulcatus (200 specimens) and Dermacentor reticulatus (4 specimens). Ticks were morphologically identified, pooled, and screened for TBEV RNA by RT-qPCR. TBEV of positive tick pools were isolated and genetically characterized by genome sequencing. Our study demonstrates the prevalence of two TBEV subtypes in Latvia with specific spatial patterning. In the sympatric Vidzeme region, these subtypes display a preferential species association of TBEV-EU with Ixodes ricinus and TBEV-Sib with Ixodes persulcatus. Phylogeographic analysis suggests independent introductions of multiple genotypes from both subtypes. Further investigations are necessary to better understand the natural transmission and the medical importance of these TBEVs. Full article

Feline cytauxzoonosis is an emerging tick-borne disease in Europe. While infections have been reported in different European countries, the tick vector remains unknown. This study investigated 665 ticks collected in 2019 (n = 160), 2022 (n = 7), and 2024 (n = 498) in a Cytauxzoon spp. hotspot region in central Switzerland (62 ticks from cats; 603 ticks from vegetation). Ticks were morphologically characterized, pooled by origin and life-stage, and screened for Cytauxzoon spp. 18S rRNA by qPCR and conventional PCR, and positive samples confirmed by sequencing. All ticks belonged to Ixodes ricinus (50 males, 83 females, 532 nymphs). Four tick pools from 2019 tested Cytauxzoon spp. positive: one pool of 3 non-engorged male ticks from two cats and three pools of 5–6 nymphs each from vegetation. All ticks collected in 2022 and 2024 tested negative. Amplification of the almost full-length (1535 bp, one pool) or partial (140–219 bp, three pools) 18S rRNA gene revealed a sequence identity of 98.6–100% with Cytauxzoon spp. previously detected in cats from this area. The detection of Cytauxzoon spp. in questing I. ricinus nymphs suggests a potential role of this tick species in the parasites’ transmission cycle in Central Europe and raises the possibility of transstadial or potentially transovarial transmission. Mitochondrial gene sequencing was unsuccessful, but the detected Cytauxzoon spp. likely represent Cytauxzoon europaeus. Discrepancies between qPCR and conventional PCR results point to possible amplification of tick endosymbionts, highlighting the importance of confirmatory sequencing, particularly when testing tick-derived DNA. Thus, the 18S rRNA qPCR assay used appears suboptimal for screening tick samples, as its specificity in this matrix was limited. In conclusion, this is the first report of Cytauxzoon spp. in questing I. ricinus ticks in Europe. Our findings underscore the need for further research to confirm vector competence and clarify transmission dynamics. Full article

Lyme borreliosis (LB), a zoonotic disease caused by Borrelia burgdorferi sensu lato and transmitted by Ixodes ricinus, is increasingly relevant in France, yet data on public awareness and prevention are limited. This cross-sectional study assessed the knowledge, attitudes, and practices (KAP) of companion-animal owners (CAOs) and veterinarians regarding LB. Online questionnaires were distributed between January and April 2023, yielding 159 valid CAO responses and 48 responses from veterinarians. Among owners, 95% reported outdoor access for their pets, 73.9% had observed ticks, and 88.8% used ectoparasiticides. However, only 16.4% reported LB vaccination, and just 38% recognized key canine clinical signs. Veterinarians frequently suspected LB (70%) but confirmed diagnoses less often (39.6%), relying mainly on clinical signs and the results of rapid tests. While prevention through antiparasitic use was common, communication between veterinarians and owners regarding LB was inconsistent. Despite this, most owners reported compliance with veterinary guidance. These findings reveal good preventive habits but identify knowledge gaps and underdiagnosis. Enhancing veterinary–client communication and promoting a One Health approach could improve LB prevention and control in France. Full article

Nanoparticles have emerged as innovative tools for combating bacterial infections, offering a potential solution to antibiotic resistance and the limitations of conventional antimicrobials. Nanoparticles exhibit antibacterial activity through multiple mechanisms, including oxidative stress induction, metal ion release, direct membrane damage, disruption of DNA and proteins, and indirect immune system enhancement. Rickettsia helvetica, R. monacensis, R. slovaca, and R. conorii subsp. raoultii are tick-borne pathogens transmitted by Ixodes ricinus, Dermacentor reticulatus, and D. marginatus ticks across Europe causing spotted fever rickettsiosis. While rickettsioses are successfully treated with antibiotics, resistance of rickettsiae to antimicrobial therapy has been reported. Here, we evaluated the anti-rickettsial activity of silver (AgNPs), selenium (SeNPs), and chitosan (CSNPs) nanoparticles against R. conorii subsp. caspia, a tick-borne bacterial pathogen, in African green monkey kidney cell line (Vero). At their highest non-cytotoxic concentrations, CSNPs exhibited the strongest inhibitory effect (87%). SeNPs also significantly reduced bacterial load (76%), although their efficacy was constrained by cytotoxicity at higher doses. In contrast, AgNPs did not show significant activity under the tested conditions. The differences observed among nanoparticles reflect both the antimicrobial properties and host cell tolerance limits. These findings highlight CSNPs and SeNPs as promising candidates for further development of nanoparticle-based strategies to combat intracellular, tick-borne pathogens. Full article

Bartonella spp. is a Gram-negative bacterium transmitted by arthropod vectors, implicated in a range of zoonotic infections affecting both humans and animals. Among zoonotic species, B. henselae is primarily associated with domestic cats and B. vinsonii with dogs. In Italy, Bartonella infections have been reported in both southern and northern regions. This study investigates the presence of Bartonella spp. in fleas and ticks collected from companion animals in Piedmont region, northwestern Italy. A total of 176 flea and 85 tick specimens were obtained from 92 animals (dogs and cats) between May 2018 and February 2020. Arthropods were morphologically identified using identification keys, and screened for Bartonella DNA by PCR targeting the 16s rRNA gene. Positive samples were further analyzed by amplifying the rpoB gene. Selected 16s-positive and all rpoB-positive samples were sequenced and subjected to phylogenetic analysis. Fleas were mostly identified as Ctenocephalides felis, recovered from 44 cats and 12 dogs; a single C. canis specimen was found in one cat. Ticks were Ixodes ricinus (from 14 cats and 10 dogs), Rhipicephalus sanguineus s.l. (3 cats, 7 dogs), and Dermacentor marginatus (one dog). Bartonella prevalence was 38.4%, with 34.2% positivity in fleas and 45.6% in ticks. All sequences corresponded to B. henselae. These findings confirm the active circulation of B. henselae in ectoparasites of pets and raise questions about the potential role of ticks in its transmission. Full article

This article presents a deep learning approach for classifying the developmental stages (larvae, nymphs, adult females, and adult males) of Ixodes ricinus ticks, the most common tick species in Europe and a major vector of tick-borne pathogens, including Borrelia burgdorferi, Anaplasma phagocytophilum, and tick-borne encephalitis virus (TBEV). Each developmental stage plays a different role in disease transmission, with nymphs considered the most epidemiologically relevant stage due to their small size and high prevalence. We developed a convolutional neural network (CNN) model trained on a dataset of microscopic tick images collected in the area of Upper Silesia, Poland. Grad-CAM, an XAI technique, was used to identify the regions of the image that most influenced the model’s decisions. This work is the first to utilize a CNN model for the identification of European tick fauna stages. Compared to existing solutions focused on North American tick species, our model addresses the specific challenge of distinguishing developmental stages within I. ricinus. This solution has the potential to be a valuable tool in entomology, healthcare, and tick-borne disease management. Full article

Migratory birds play a key role in the ecology of tick-borne pathogens, serving as both hosts for ticks and as potential carriers of a wide range of infectious agents that can affect wildlife, domestic animals, and humans. Their long-distance movements contribute to the dispersal of ticks and the pathogens they harbor, with potential implications for the emergence and spread of zoonotic disease. This study focuses on the prevalence of Rickettsia spp. and Babesia/Theileria spp. in ticks collected from migratory birds in Sardinia, Italy, during two consecutive migration seasons (April–May and October–November 2021), corresponding to the spring and autumn migratory periods. A total of 961 ticks, primarily Ixodes ricinus, was collected from various bird species. Molecular analyses using polymerase chain reaction (PCR) and sequencing enabled the detection and identification of multiple Rickettsia species, with R. helvetica, R. monacensis, and R. aeschlimannii being the most frequently identified. Protozoan pathogens, including B. venatorum and Theileria ovis, were also detected in the tick samples. These findings underscore the diversity of pathogens in bird-associated ticks and the role of migratory birds in the geographical spread of these diseases. These results also provide valuable insights into pathogen transmission dynamics and stress the importance of monitoring migratory birds to assess and mitigate the risks of zoonotic diseases. Further research is needed to clarify the ecological interactions among birds, ticks, and pathogens across different geographic regions. Full article

This study aimed to assess the emergence and/or re-emergence of Tick-borne Diseases (TBD) in Portugal by linking the hemoparasite burden in companion animals to vector-borne disease dynamics through a One Health approach. Between 2015 and 2024, 1169 clinically suspected animals with hemoparasite infections, treated at the Hospital Veterinário de Santarém (HVS), underwent serological confirmation for Rickettsia conorii, Babesia canis, Ehrlichia spp., and Haemobartonella spp. A total of 3791 serological tests (3.2 tests per animal) were performed and 437 animals tested positive for at least one of the four hemoparasites under investigation. From 2020 to 2024, tests nearly tripled from 894 to 2883, raising positive cases and prevalence from 29.5% to 39.9%, especially for rickettsiosis and hemobartonellosis, indicating an increased circulation of their vectors. A national vector surveillance initiative identified Hyalomma spp., Rhipicephalus sanguineus, Ixodes ricinus, and Dermacentor sp. as primary tick vectors in Portugal for the hemoparasites mentioned above and for other agents like arbovirus, such as Crimean-Congo Hemorrhagic Fever Virus (CCHFV) and tick-borne encephalitis virus (TBEV). This study found that the vectors responsible for transmitting hemoparasitosis, given the high number of serologically positive cases detected in the HVS, represent an increasing risk for TBD. These findings highlight the relevance of companion animal monitoring as an early-warning component within a One Health surveillance approach. Full article

Ixodiphagus hookeri (Howard, 1907) (Hymenoptera: Encyrtidae), a hyperparasitic wasp that parasitizes hard ticks, has been documented in various parts of Europe; however, data on its presence in southeastern regions has been lacking. This study provides the first molecular evidence of I. hookeri in ticks from the coastal areas of the Balkan Peninsula, specifically Croatia and Bulgaria. A total of 1043 questing ticks were collected between 2011 and 2013 across 15 locations. Molecular screening revealed I. hookeri DNA in Ixodes ricinus (Linnaeus, 1758) (Acari: Ixodidae) nymphs from inland Croatia (overall prevalence: 18.72%) and in Haemaphysalis concinna (Koch, 1844) (Acari: Ixodidae) nymphs and larvae from coastal Bulgaria (prevalence: 17.2%). All I. hookeri-positive samples were co-infected with Wolbachia spp. (Rickettsiales: Anaplasmataceae). This detection marks the southernmost record of I. hookeri in Central Europe, expanding its known range to the Balkan Peninsula and supporting its relevance as a potential natural enemy in integrated tick management strategies. Full article

Neoehrlichia mikurensis and Anaplasma phagocytophilum, both members of the Anaplasmataceae family, are pathogens that can cause diseases in animals and humans. Ixodid ticks are the primary vectors for both species. While urban green spaces offer various ecological and social benefits, there is increasing evidence suggesting potential public health risks, particularly increased exposure to vector-borne diseases. The aim of the present study was to assess the prevalence and co-occurrence of A. phagocytophilum and N. mikurensis in ticks from urban environments in Lithuania. A total of 3599 Ixodes ricinus and 29 Dermacentor reticulatus were collected from 31 urban and 21 peri-urban areas. Ticks were examined for pathogens using duplex real-time PCR. Anaplasma phagocytophilum was detected in 4.47% of tested ticks, while N. mikurensis in 6.17%. Co-infection was found in 0.42% of I. ricinus specimens. Phylogenetic analysis of the groEl gene revealed low genetic variability of N. mikurensis and the circulation of two ecotypes (I and II) of A. phagocytophilum. Additionally, Ehrlichia muris was identified in I. ricinus ticks. This study is the first report of N. mikurensis detection in ticks from Lithuania. Our findings highlight the potential risk posed by tick-borne pathogens in urban and peri-urban areas of the country. Full article

The Kaliningrad Oblast, located in the westernmost part of Russia and bordering European Union countries, is a popular tourist destination. However, limited research has been conducted on the bacteria found in ticks in this region. We, therefore, investigated the prevalence of certain bacteria, including Borrelia, Rickettsia, Anaplasma, and Ehrlichia, as well as the genospecies of the spotted fever group Rickettsia (SFGR) in Ixodes ricinus and Dermacentor reticulatus tick species. To accomplish this, we employed commercial qPCR for pathogen screening. We identified specific genospecies by sequencing the gltA and ompA gene fragments. In I. ricinus ticks, we found Borrelia burgdorferi sensu lato DNA in 35.6% of samples. We also found Rickettsia helvetica in 17.5% of ticks. Additionally, we detected Borrelia miyamotoi in 1.7% and Anaplasma phagocytophilum in 2.6%, while Ehrlichia chaffeensis/Ehrlichia muris were present in 0.6%. In D. reticulatus ticks, we detected only Rickettsia conorii subsp. raoultii DNA, with a prevalence of 6.1%. These findings demonstrate a substantial risk of Lyme disease and other tick-borne infections from early spring through late autumn, emphasizing the importance of ongoing monitoring for these pathogens in the region. Full article

Lyme borreliosis (LB), caused by Borrelia burgdorferi sensu lato (s.l.) and babesiosis, caused by Babesia divergens and Babesia venatorum, are both transmitted by the ixodid tick Ixodes ricinus. Although these diseases coexist in Spain and other European regions, no studies have been carried out to assess the impact on the health of patients exposed to both causative pathogens. This retrospective study, conducted in Asturias in northwestern Spain between 2015 and 2017, analyzed the possible complications arising from exposure to these pathogens. To this end, the epidemiological, clinical and analytical features of two groups of a cohort of 120 LB patients exposed to one or two of the pathogens were compared. The cohort comprised 73 patients who had only been infected with Bo. burgdorferi s.l. (Bb group) and 47 patients who were seropositive for Ba. divergens/venatorum in addition to being infected with Bo. burgdorferi s.l. (BbBdv group). The results showed that LB patients who had also been exposed to infection with Babesia spp. (BbBdv group) had significantly more cardiorespiratory symptoms, in particular dyspnea and first- and second-degree atrioventricular (AV) blocks, compared to those who had been infected with Bo. burgdorferi s.l. alone (Bb group). No relevant differences in other symptoms, epidemiological factors or analytical tests were observed between the two groups. Full article

Hard ticks are vectors of a wide range of pathogens, with tick-borne bacteria being among the most frequently detected. This study presents a first approach to the identification of human-biting ticks in the Basque Country (northern Iberian Peninsula), where previous research has mainly focused on ticks from vegetation and domestic and wild animals. The aim of this study was (i) to identify tick species collected in hospitals and health centres and (ii) to determine the presence and identify of pathogenic bacteria that they may carry using PCR, RLB and sequencing methods. A total of 181 ticks were collected and grouped in pools of one, two or three specimens, resulting in 157 samples. Morphological and molecular identification of collected ticks revealed that most specimens belonged to Ixodes ricinus (88.5%). Additionally, Rhipicephalus bursa, Haemaphysalis punctata, Dermacentor reticulatus and Dermacentor marginatus were also identified. A total of 25 samples (15.9%) tested positive for DNA from the targeted pathogens. The most prevalent vector-borne bacteria were Borrelia spp. (6.4%), followed by Rickettsia spp. (5.1%), Anaplasma phagocytophilum (2.5%) and Coxiella spp. (1.9%). Species identified included B. afzelii, B. garinii, B. miyamotoi, B. valaisiana, B. burgdorferi s. s., R. monacensis, “Candidatus R. rioja”, R. helvetica and R. massiliae. This study highlights the usefulness of combining molecular diagnostics with passive surveillance of human-attached ticks as an effective tool for regional monitoring of ticks and tick-borne pathogens. Full article