Search Results (51)

Tick-borne diseases account for a substantial proportion of the global incidence of infectious diseases, and their recent expansion has been increasingly associated with climate change. Nevertheless, previous studies have produced heterogeneous and often inconclusive results, largely due to differences in spatial scale, variable selection, and limited integration of climatic, ecological, and host-related drivers. Here, we assess the modeled impact of climate trends on the global distribution patterns of ticks parasitizing humans and livestock, rather than changes in tick abundance or pathogen transmission. This study is not an evaluation of human or animal contact rates with ticks. Using the largest curated compilation of georeferenced tick records available to date (213,513 records from 138 Ixodidae species), we adopt a global, climate-centered perspective based on the Holdridge life zones framework. The study characterized current climatic niches of tick genera and projected changes in suitability under future climate scenarios for 2040, 2060, 2080, and 2100. Our results reveal a strong association between tick occurrence patterns and large-scale gradients of temperature and atmospheric water balance, while precipitation plays a comparatively minor role. Projections indicate increasing climatic suitability for human-biting ticks at higher northern latitudes, concurrent with declining suitability across parts of central and southern Africa. By integrating modeled suitability with human population projections and livestock distributions, we estimated future changes in exposure risk. Although local processes such as tick abundance and pathogen prevalence are beyond the scope of this study, our findings provide a coherent global synthesis of how climate change may reshape tick distributions and associated risks. Full article

Tick-borne pathogens (TBPs) are increasingly recorded in urban areas, where synanthropic wildlife may sustain pathogen transmission cycles. The European hedgehog (Erinaceus europaeus), frequently infested with ectoparasites, may serve as an urban reservoir of zoonotic TBPs. We investigated TBPs in host tissues and associated ectoparasites (Ixodes spp. and Archaeopsylla erinacei) from 129 hedgehogs in northwestern Italy. Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato and Rickettsia spp. were detected in skin, spleen and ectoparasites (Ixodes spp. and Archaeopsylla erinacei). One spleen sample was positive for B. miyamotoi. Molecular identification revealed A. phagocytophilum ecotype 1, B. afzelii and B. bavariensis. A flea-borne Rickettsia closely related to the zoonotic Rickettsia asembonensis was identified for the first time in European hedgehogs. All pathogens were more prevalent in skin than in spleen. In skin, A. phagocytophilum and B. burgdorferi s.l. showed a positive interaction, whereas both were negatively associated with Rickettsia spp. These findings highlight hedgehogs as potential urban reservoirs of zoonotic TBPs, posing a potential risk for humans and domestic animals. The marked skin tropism of these pathogens supports the use of skin for TBP surveillance and underlines its role as a key interface for vector-borne transmission. Full article

Ticks use multiple sensory organs to facilitate host detection, including Haller’s organs (HOs) that allow ticks to sense infrared (IR) radiation from potential hosts. Additionally, ticks have primitive eyes to sense light sources. The possibility exists that these senses may detect stimuli that attract ticks to road edge habitat, where IR radiation tends to be elevated. We investigated the role of the HOs and eyes in the attraction of adult American dog ticks, Dermacentor variabilis, towards road edge habitat(s). Adult D. variabilis were collected from multiple study sites and separated into three groups: (1) Haller’s organs removed; (2) eyes painted with black nail polish; and (3) unmodified ticks (control). All tick groups were marked with a unique fluorescent paint color and released 7.5 m from the road edge at two study sites. Tick movements were tracked at night using ultraviolet lights, tick position(s) were recorded using flags, and measurements were recorded to track tick movement in relation to the release point and road edge. Surface temperatures were recorded at the road edge and in the field to detect a potential thermal stimulus. Mixed-effects models were applied to investigate the significance of tick proximity to the road edge between the groups and sites. Our results demonstrated that the control unmodified group was significantly closer to the road edge than the modified groups lacking Haller’s organ or eyes (p ≤ 0.0001, p = 0.0049), leading to the conclusion that unmodified ticks move towards road edges. Modifying ticks, either by removing the HO or eyes of adult D. variabilis decreased tick movement toward road edges. Full article

This study investigates how climate gradients shape tick–host associations, testing the hypothesis that variations in climate leverage some associations, which can be ecosystem-specific. To test this hypothesis, we modelled tick–host associations across the Western Palearctic using climatic variables and a large dataset of georeferenced tick (seven species, n = 23,462) and vertebrate host records (n = 6.5 million across 162 species aggregated into 50 genera). Niche overlap with hosts is highly variable but consistently significant (p < 0.05) in every tested ecosystem of the target territory. Montane grasslands exhibit the lowest values of tick–host niche overlap, meaning that they support the smallest but still resilient set of available hosts. Host phylogenetic diversity (PD) depends on the ecosystem rather than tick species; PD is lowest in montane grasslands (supporting previous results) and in the case of D. reticulatus in savannas and scrubland. Nestedness of tick–host networks, known to be related to the resilience of parasite–host networks, is highest in climatically extreme ecosystems, reflecting adaptability of tick–host networks, as measured by niche overlap on modelled distribution. Multidimensional scaling confirms that host community composition and niche overlap vary significantly across ecosystems, supporting the hypothesis of host rewiring under diverse climatic conditions. These findings may have important implications for the concept of community composition and the circulation of tick-borne pathogens. 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

Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne zoonotic pathogen of growing public health concern in southeastern Europe. This study provides the first serological evidence of CCHFV circulation in Croatia, based on testing 1473 serum samples from farm and companion animals, including sheep, horses, cattle, goats, dogs, and cats. A total of 109 samples (7.4%) tested positive for CCHFV antibodies using a commercially available enzyme-linked immunosorbent assay (ELISA) kit. The highest seroprevalence was recorded in sheep (28.3%), followed by horses (4.3%) and a single cat (0.5%), with no antibodies detected in cattle, goats, or dogs. Almost all seropositive animals originated from coastal and subcoastal Croatia, where Hyalomma ticks are present. Only two seropositive cases were detected in continental areas. Sheep samples from several farms in Zadar County showed intra-farm seropositivity rates of up to 85.7%, suggesting localised virus circulation likely influenced by vector distribution and farm-level practices. No viral ribonucleic acid (RNA) was detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR), consistent with the transient nature of viremia in most animal hosts. These findings confirm the silent circulation of CCHFV in Croatia and reinforce the need for targeted, regionally adapted surveillance strategies that integrate multiple hosts and support early warning systems aligned with the One Health concept. Full article

Kyasanur Forest Disease (KFD), first reported in 1957 in the Shimoga district of Karnataka, India, has spread significantly over the past two decades, reaching both northern and southern states, with reports of monkey deaths. Haemaphysalis spp. ticks are the primary vectors, transmitting the disease to monkeys, humans, and other mammals. This study aimed to assess the prevalence, mean abundance, and mean intensity of Ixodidae ticks, including the KFD vector, in domestic animals across selected localities of the Western Ghats. A total of 2877 domestic animals were surveyed, revealing an overall tick prevalence of 44.91% (CI: 43.10–46.73), with sheep showing the highest prevalence at 47.92% (CI: 40.96–54.95). The most abundant tick species was Rhipicephalus (Boophilus) microplus, with a mean of 2.53 ± 0.66 ticks per host, which also represented the most proportionally dominant species, accounting for 39.63% of the total ticks collected. The highest mean intensity was recorded for Haemaphysalis intermedia (7.35 ± 2.03 ticks per infested animal). Regionally, Rh. (Bo.) microplus was found in 96.15% of buffaloes examined in Tamil Nadu, Haemaphysalis bispinosa in 85.19% of cattle in Maharashtra, and in 98.46% of goats in Goa. Ha. intermedia was common in 99.11% of sheep examined in Karnataka, while Ha. bispinosa was observed in 90.82% of goats in Kerala. The proportional representation of the KFD vector Haemaphysalis spinigera was 0.97%, with a mean intensity of 2.34 ± 0.04 ticks per infested animal and an overall mean abundance of 0.06 ± 0.01 ticks per host. Adult Ha. spinigera were recorded from cattle, buffaloes, sheep, goats, and dogs; however, no nymphs were detected. This study also reports the first documented occurrence of Ixodes ceylonensis in domestic animals. These findings suggest a notable presence of tick infestations in the region and emphasize the importance of continued surveillance and targeted control measures to better understand and manage potential KFD transmission risks in the Western Ghats. Full article

The wild boar (Sus scrofa) has experienced significant population growth as well as geographic expansion across Europe over the past 15 years, leading to increased concerns regarding its role in the transmission of zoonotic pathogens. Among these, Babesia spp. and Anaplasma spp. are of particular importance due to their impact on both wildlife and domestic animals. This study systematically reviews the prevalence and distribution of Babesia and Anaplasma spp. in wild boars and associated tick vectors across multiple European countries, synthesizing data from literature published between 2010 and 2024. A comprehensive search of Scopus, Google Scholar, and PubMed databases was conducted using predefined keywords related to babesiosis, anaplasmosis, wild boars, Europe, and tick-borne diseases. A total of 281 studies were initially retrieved, of which 19 met the inclusion criteria following relevance assessment. Data extraction focused on pathogen identification, diagnostic methods, sample type, host species, and prevalence rates. Molecular detection methods, primarily PCR and sequencing, were the most used diagnostic tools. Results indicate substantial regional variations in the prevalence of Babesia and Anaplasma spp. A. phagocytophilum was detected in wild boar populations across multiple countries, with the highest prevalence rates observed in Slovakia (28.2%) and Poland (20.34%). Conversely, lower prevalence rates were recorded in France (2%) and Portugal (3.1%). Babesia spp. showed higher prevalence rates in Italy (6.2%), while its detection in other regions such as Romania and Spain was minimal or absent. Notably, spleen and multi-organ samples (spleen/liver/kidney) exhibited higher positivity rates compared to blood samples, suggesting an organotropic localization of these pathogens. The findings underscore the role of wild boars as reservoirs for tick-borne pathogens and highlight their potential to contribute to the epidemiological cycle of these infections. The increasing distribution of wild boars, coupled with climate-driven shifts in tick populations, may further facilitate pathogen transmission. Future studies should focus on integrating molecular, serological, and ecological approaches to improve surveillance and risk assessment. Standardized methodologies across different regions will be essential in enhancing comparative epidemiological insights and informing targeted disease management strategies. Full article

Background: Chemosensation in ticks opens a novel and unique field for scientific research. This study highlights ticks’ chemosensory system to comprehend its host-searching behavior and other integrated chemistry and biology involving Haller’s structure. Methodology: This study combines microanatomical, electrophysiological, and behavioral experiments to investigate the role of Haller’s organ in adult ticks in response to different classes of organic compounds. Results: We showed the microscopic anatomy of Haller’s organ in Haemaphysalis darjeeling, present at the terminal segment of the first pair of appendages. Haller’s structure serves a vital function in perceiving odor. The electrophysiological activity of adult ticks to different classes of organic compounds via electroscutumography was explored at five different concentrations: w/v 0.001, 0.01, 0.1, 1.0, and 2.0%. Among 55 organic compounds, moderate to high stimulation was recorded with pyruvate (13.28 mv at 2%), ammonia (12.26 mv at 2%), benzoic acid (1.99 mv at 0.001%), isobutyric acid (1.39 mv at 0.001%), 2,6-dichlorophenol (1.34 mv at 0.001%), p-Tolualdehyde (1.26 mv at 2%), tetradecane (1.23 mv at 2%), docosane (1.17 mv at 2%), citronellal (1.13 mv at 0.1%), isopropyl acetate (1.05 mv at 0.01%), cyclohexanol (1.03 mv at 2%), 1-octane-3-ol (1.02 mv at 2%), and 1-octanol (1.01 mv at 0.001%). Olfactometric bioassays at w/v 2.0% concentration further confirmed that ammonia, pyruvate, 1-octane-3-ol, hematin porcine, p-Tolualdehyde, methyl salicylate, uric acid, tetradecane, carbon dioxide, propanoic acid, 3-hexanol, hexanoic acid, adenine, 2,6-dichlorophenol, hexadecane, heptanoic acid, pentanoic acid, octadecane, guanine, and nonanoic acid acted as strong attractants, while citronellal, eugenol, butyric acid, geraniol, benzaldehyde, and tiglic aldehyde showed an active repellent effect against the tick species. Conclusions: This investigation provides knowledge of the olfactory sensilla of Haller’s structure as biosensors behind tick olfaction and the possibility for chemical detection of diverse attractants and repellents for future development of anti-tick compounds. Full article

Background: Climate warming and anthropogenic environmental changes impact the spread of ticks and tick-borne pathogens (TBPs). This study investigated the occurrence of ticks and the risk of TBPs infection in urban and rural recreational areas in Eastern Poland at record-high temperatures in winter. Methods: Ticks were collected from vegetation using the flagging method. Various types of polymerase chain reactions were applied to detect Borrelia burgdorferi s.l., Anaplasma phagocytophilum, Rickettsia spp., and Babesia spp. in the studied ticks. Results: 268 ticks were sampled in the four urban/suburban and one rural sites, including 78 Ixodes ricinus specimens and 190 Dermacentor reticulatus ticks. Of the ticks, 49.19% were infected by at least one TBP, including 41.03% of I. ricinus and 63.04% of D. reticulatus specimens. Co-infections with TBPs that involved only I. ricinus were recorded in 6.41% of these ticks. Conclusions: The study indicates that hosts are exposed to tick attacks and TBPs infection in Central Europe at high temperatures in winter. The high activity of ticks may increase the incidence of tick-borne diseases in humans and companion animals. The record’s importance indicates that practical preventive measures against TBPs should be taken due to weather conditions rather than the season. Full article

The Trypanosomatidae family encompasses around 24 genera of unicellular protozoans, many of which are transmitted by various hematophagous arthropods, particularly members of the Orders Diptera and Hemiptera. Fleas and ticks—an understudied group of ectoparasites—have been shown to be hosts of a wide and crescent variety of trypanosomatid species. Further, fleas and ticks of companion animals have been particularly neglected in trypanosomatid surveillance despite the proximity to human populations and the anthropophagous habits of many of these arthropods, which can potentially act as vectors of zoonotic trypanosomatids. We aimed to identify the presence, characterize the species, and establish the prevalence of Kinetoplastids, including members of the Trypanosomatidae family, in ectoparasites collected from dogs and humans from Mexico. A total of 537 ectoparasite specimens belonging to six ectoparasite taxa (Amblyomma mixtum, A. tenellum, Ctenocephalides felis felis, Pulex simulans, Rhipicephalus linnaei, and Rh. sanguineus s.s.) were collected from 15 States of Mexico. An 800 bp fragment of the 18S-rDNA gene from kinetoplastids was amplified and sequenced. The presence of two agents (Trypanosoma caninum and Parabodo sp.) was detected in R. linnaei ticks and one (Blechomonas lauriereadi) in the cat flea Ct. felis felis. This is the first record of genetic material of kinetoplastid species in ectoparasites from dogs and humans in Mexico. Full article

Ticks are important vectors of pathogenic bacteria that cause diseases in both humans and animals. Analysis of tick microbiota via massive sequencing allows rapid and comprehensive identification of almost all bacteria inhabiting ticks. This has improved the detection of emerging pathogens and has helped define their relationship with public health. In Mexico, the brown dog tick (Rhipicephalus sanguineus sensu lato) is a public health problem, especially in northeast Durango. In the present study, the bacterial microbiota of this tick was determined using third-generation massive sequencing (PacBio, V1–V9 region of the 16S rRNA gene); bacteria with pathogenic potential that are transmitted by salivation and those that can be transmitted by accidental regurgitation of the parasite were also identified. In 2024, 60 dogs were searched for unfed ticks; then, 15 groups of female ticks and 15 groups of male ticks were formed, with each group consisting of 30 individuals. DNA was extracted from each tick pool, and the complete 16S rRNA gene was amplified (PacBio). Bioinformatics analysis was performed in QIIME2 (Quantitative Insights into Microbial Ecology) to obtain amplicon sequence variants (ASVs). Alpha and beta diversity metrics, as well as statistical analyses, were performed to test for differences between the microbiota of females and males. The bacterial taxa were classified into 21 phyla, 24 classes, 81 orders, 137 families, 339 genera, and 565 species. The male microbiota presented a significantly greater number of ASVs and a greater phylogenetic diversity index (FaithPD). Additionally, the unweighted UniFrac metric was significantly different between the sexes. The endosymbiont Coxiella mudrowiae was significantly more abundant in females, and Ehrlichia canis was more abundant in males. The pathogens E. canis and Anaplasma platys (transmitted by salivation) were detected, as well as 75 species of potential pathogens recorded in this tick that could enter the host in case of accidental regurgitation of the parasite (e.g., Staphylococcus, Streptococcus, Acinetobacter, Corynebacterium, Proteus, Clostridum, Klebsiella, Bacillus, Escherichia, Fusobacterium, and Pasteurella). It is necessary to continue analyzing the microbiota of ticks through massive sequencing for the benefit of public health and to establish new alternatives for controlling these parasites. Full article

Despite the seriousness of the disease carried by ticks, little is known about the Bourbon virus. Only three US states have recorded human cases of Bourbon virus (BRBV) infection; in all cases, a tick bite was connected with the onset of the illness. The Bourbon virus (BRBV) belongs to the Orthomyxoviridae family and Thogotovirus genus, originating in the states of the US, i.e., Kansas, Oklahoma and Missouri. The growing rates of BRBV infections in various parts of the US highlight the necessity for a thorough analysis of the virus’s transmission mechanisms, vector types and reservoir hosts. Currently, there are no vaccines or efficient antiviral therapies to stop these infections. It is imperative to produce a vaccination that is both affordable and thermodynamically stable to reduce the likelihood of future pandemics. Various computational techniques and reverse vaccinology methodologies were employed to identify specific B- and T-cell epitopes. After thorough examination, the linker proteins connected the B- and T-cell epitopes, resulting in this painstakingly constructed vaccine candidate. Furthermore, 3D modeling directed the vaccine construct toward molecular docking to determine its binding affinity and interaction with TLR-4. Human beta-defensin was used as an adjuvant and linked to the N-terminus to boost immunogenicity. Furthermore, the C-IMMSIM simulation resulted in high immunogenic activities, with activation of high interferon, interleukins and immunoglobulin. The results of the in silico cloning process for E. coli indicated that the vaccine construct will try its utmost to express itself in the host, with a codon adaptation CAI value of 0.94. A net binding free energy of −677.7 kcal/mol obtained during docking showed that the vaccine has a high binding affinity for immunological receptors. Further validation was achieved via molecular dynamic simulations, inferring the confirmational changes during certain time intervals, but the vaccine remained intact to the binding site for a 100 ns interval. The thermostability determined using an RMSF score predicted certain changes in the mechanistic insights of the loop region with carbon alpha deviations, but no major changes were observed during the simulations. Thus, the results obtained highlight a major concern for researchers to further validate the vaccine’s efficacy using in vitro and in vivo approaches. Full article

Haemaphysalis longicornis (Neumann), the Asian longhorned tick, is a species native to East Asia, but invasive to Australia, New Zealand, and most recently, the United States. It has spread rapidly across the eastern United States after being established in New Jersey in 2017. Aiding this rapid expansion is the ability of this tick to reproduce parthenogenically and feed on diverse host species. In cattle, this tick can cause heavy burdens and act as a vector for the pathogenic hemoprotozoan parasite Theileria orientalis, genotype Ikeda, creating economic losses that impact the cattle industry. Here, we report Asian longhorned ticks, collected from cattle, a dog, and pastures and morphologically identified at the Oklahoma Animal Disease Diagnostic Laboratory as H. longicornis before molecular confirmation through PCR amplification of the cox1 gene. Blood samples from infested cattle were collected and assessed molecularly for the presence of T. orientalis, with no pathogenic DNA detected. This report describes the first record of H. longicornis in Oklahoma and the farthest westward detection of this tick in the United States to date. Full article

Emerging infectious diseases (EIDs) are newly emerging and reemerging infectious diseases. The National Institute of Allergy and Infectious Diseases identifies the following as emerging infectious diseases: SARS, MERS, COVID-19, influenza, fungal diseases, plague, schistosomiasis, smallpox, tick-borne diseases, and West Nile fever. The factors that should be taken into consideration are the genetic adaptation of microbial agents and the characteristics of the human host or environment. The new approach to identifying new possible pathogens will have to go through the One Health approach and omics integration data, which are capable of identifying high-priority microorganisms in a short period of time. New bioinformatics technologies enable global integration and sharing of surveillance data for rapid public health decision-making to detect and prevent epidemics and pandemics, ensuring timely response and effective prevention measures. Machine learning tools are being more frequently utilized in the realm of infectious diseases to predict sepsis in patients, diagnose infectious diseases early, and forecast the effectiveness of treatment or the appropriate choice of antibiotic regimen based on clinical data. We will discuss emerging microorganisms, omics techniques applied to infectious diseases, new computational solutions to evaluate biomarkers, and innovative tools that are useful for integrating omics data and electronic medical records data for the clinical management of emerging infectious diseases. Full article