Search Results (149)

Infections caused by arboviruses, a diverse group of viral pathogens transmitted by biting arthropod vectors, mainly mosquitoes, ticks, and midges, can cause a range of illnesses in humans, from mild, influenza-like symptoms to severe neurological complications including encephalitis and viral hemorrhagic fever. According to 2024 World Health Organization statistics, vector-borne diseases collectively account for over 700,000 human deaths annually, with mosquito-borne infections such as dengue, chikungunya, Zika, and yellow fever constituting a growing and significant proportion of this burden. What was once considered a problem localized to poorly resourced settings in tropical and subtropical regions is now becoming a pervasive global challenge. This is due largely to a combination of factors including climate change, transcontinental travel, and urbanization, with the geographical spread and intensity of arboviral outbreaks reaching unprecedented levels during the current century. In much the same way that the escalating global burden of bacterial infections resistant to antibiotics has been described as a silent pandemic, the insidious rise of arboviruses begs questions regarding outbreak preparedness, prevention and control. Here, we highlight the pressing need for comprehensive strategies that incorporate various health sectors to mitigate the emergence and resurgence of arboviral diseases. Future directives that should be prioritized are outlined. As demonstrated by epidemiological trends and historical outbreak data, an orchestrated global response is critical not only for managing current threats but also for preventing future epidemics. Full article

Lyme disease is the most common vector-borne disease in North America. Predicting Lyme disease incidence is a key component of public health preparedness. Previously, we demonstrated that the volume of data searches on Google Trends for terms related to Lyme disease, such as “Lyme” and “tick bite”, can be used as a tool to predict monthly human Lyme disease incidence at the state level. The objective of this project was to build upon our previous work by adding environmental and canine data to our predictive models for the prediction of state-level human and canine Lyme disease incidence. Human data were acquired from state health departments. Canine data were acquired from IDEXX Laboratories. We hypothesized that incorporating a One Health approach with human, animal, and environmental data would improve the predictive ability of the models. The One Health model performed significantly better (Mean Absolute Error [MAE] = 12.1) in predicting human disease incidence in 6 out of 16 states compared to the environmental data model (MAE = 16.5), human search terms model (MAE = 21.4), canine data (search terms + case count) model (MAE = 31.1), and the canine case data model (MAE = 32.0). For canine Lyme disease incidence, the One Health model performed worse (MAE = 330.5) compared to the canine search data model (MAE = 282.3), the human data (search terms + cases) model (MAE = 248.4), and the environmental data (MAE = 221.5) model. However, even the best-performing models had large prediction errors, which limit practical utility. Future studies should incorporate alternative data streams, such as electronic health records and insurance claims, to test predictive ability. Full article

Crimean-Congo hemorrhagic fever virus (CCHFV) is transmitted predominantly through the bite of infected Hyalomma ticks, yet the earliest events at the vector–host–virus interface in human skin remain largely undefined. This review synthesizes current knowledge of human cutaneous structure and immunity, tick feeding biology, and salivary immunomodulation to propose how local skin responses may shape systemic outcomes of CCHFV disease. We detail the roles and permissiveness of major skin-resident and infiltrating cell types, including keratinocytes, melanocytes, Langerhans cells, dermal dendritic cells, monocytes/macrophages, fibroblasts, granulocytes, T cells, B cells, NK cells, and innate lymphoid cells, in antiviral defense and as potential early targets or carriers of CCHFV. Emphasis is placed on how tick saliva components reprogram the cutaneous microenvironment, alter interferon, complement, inflammasome, and cytokine pathways, and may enable saliva-assisted transmission and viral dissemination from the dermis. We highlight mounting evidence from other arboviruses demonstrating that the skin can act as both a barrier and a major amplifying organ, and we extrapolate testable hypotheses on how early cutaneous immune dynamics might influence CCHFV severity and hemorrhagic manifestations. Finally, we outline key knowledge gaps that, if answered, may inform the development of vaccines and therapeutics that harness cutaneous immunity to block systemic spread. Full article

Arthropod-borne diseases are increasingly reported in temperate regions, reflecting the combined effects of climate variability, environmental change, and global movement of humans and animals. This review addresses how different arthropod vectors contribute to disease emergence in these regions and aims to identify shared and vector-specific drivers of transmission. A comparative synthesis of recent literature was conducted focusing on mosquitoes, ticks, sandflies, and biting midges, using a stage-based framework encompassing introduction, establishment and overwintering, seasonal amplification, and spillover to humans or animals. The analysis shows that although climate-related factors commonly facilitate expansion, the biological traits of each vector group strongly influence persistence, transmission dynamics, and detectability. Differences in overwintering capacity, host associations, and dispersal mechanisms result in distinct emergence pathways and surveillance challenges. The findings indicate that early warning indicators and control options are highly context dependent and cannot be applied uniformly across vector groups. This narrative review concludes that effective preparedness in temperate regions requires surveillance and intervention strategies tailored to specific vectors and ecological settings. Full article

Lyme disease causes a significant financial and health burden. Recent advances in developing new Lyme disease vaccines have renewed optimism that vaccination may serve as an additional strategy to reduce this burden. Vaccination alone will not address the broader relevant public health challenges posed by ticks. Our experience with prior Lyme disease vaccines suggests that even an effective vaccine would not fully reduce the incidence of human disease. Importantly, vaccination against Borrelia genospecies would not affect tick abundance or exposure risk. It would also not mitigate the transmission of other tick-borne pathogens that are proliferating in human-biting ticks. Tick-borne disease risk is shaped by the biological features of ticks and tick-borne disease agents, which differ from those of mosquitoes and mosquito-borne disease agents. Unique tick characteristics create opportunities for exposure and complicate prevention and post-exposure case management. In addition to infectious diseases, ticks are associated with non-infectious conditions such as tick paralysis and alpha-gal syndrome that will not be affected by a Lyme disease vaccine. The introduction of a Lyme disease vaccine should be viewed as one part of a broader risk management strategy. Emphasis must remain on clinical awareness and education for at-risk individuals. Personal protective behaviours, surveillance, and integrated tick control will also be essential to managing tick-associated health risks in both vaccinated and unvaccinated populations. Full article

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

Background: Parasitic skin-related conditions represent a frequent and evolving challenge in human dermatology, as they often mimic other dermatoses, and are increasingly complicated by therapeutic resistance. With this study, we aimed to provide a practical, clinician-oriented overview of our experience, contextualising it within the current literature. Materials and Methods: We conducted a retrospective, single-centre observational study, reporting a case series of 88 patients diagnosed with parasitic or arthropod-related skin infestations at the San Raffaele Hospital Dermatology Unit (Milan) between 2019 and 2024, and integrated a concise narrative review of contemporary evidence on diagnosis, non-invasive imaging and management. For each case, we documented clinical presentation, dermoscopic or reflectance confocal microscopy (RCM) findings, and treatment response. Non-invasive tools (dermoscopy, videodermoscopy, RCM) were used when appropriate. Results: The spectrum of conditions included flea bites, bed bug bites, cutaneous larva migrans, subcutaneous dirofilariasis, Dermanyssus gallinae dermatitis, pediculosis, tick bites (including Lyme disease), myiasis, scabies, and cutaneous leishmaniasis. One case of eosinophilic dermatosis of haematologic malignancy was also considered due to its possible association with arthropod bites. Non-invasive imaging was critical in confirming suspected infestations, particularly in ambiguous cases or when invasive testing was not feasible. Several cases highlighted suspected therapeutic resistance: a paediatric pediculosis and three adult scabies cases required systemic therapy after standard regimens failed, raising concerns over putative resistance to permethrin and pyrethroids. In dirofilariasis, the persistence of filarial elements visualised by RCM justified the extension of antiparasitic therapy despite prior surgical removal. Conclusions: Our findings underline that accurate diagnosis, early intervention, and tailored treatment remain essential for the effective management of cutaneous infestations. The observed vast spectrum of isolated parasites reflects broader health and ecological dynamics, including zoonotic transmission, international mobility, and changing environmental conditions. At the same time, diagnostic delays, inappropriate treatments, and neglected parasitic diseases continue to pose significant risks. To address these challenges, clinicians should remain alert to atypical presentations, and consider a multidisciplinary approach including the consultation with parasitologists and veterinarians, as well as the incorporation of high-resolution imaging and alternative therapeutic strategies into their routine practice. Full article

Tick-borne diseases are rising across Europe, yet human-biting tick data from the central Balkans remain limited. We analysed ticks removed from patients seeking care after tick bites at centers in Skopje (North Macedonia) and Novi Sad (Serbia) between January 2022 and December 2024, recording species, developmental stage, month of removal, and anatomical attachment site. A total of 1641 ticks were collected (North Macedonia, n = 157; Serbia, n = 1484) and identified morphologically. Six tick species were detected in North Macedonia and eight in Serbia. Ixodes ricinus was dominant in both countries, comprising ~69% of ticks in North Macedonia and >90% in Serbia, while Hyalomma marginatum was found in North Macedonia. Adult females predominated among ticks in North Macedonia (75.8%), whereas nymphs were most frequent among ticks in Serbia (55.6%); between-center comparisons of developmental stage should be interpreted cautiously given the marked sampling imbalance. In both settings, collections peaked in May–June (~64% of annual ticks), indicating highest bite pressure in late spring/early summer. Attachment sites were most commonly the torso and lower extremities, with significant between-country differences and species-/stage-specific patterns most evident in Serbia. These data refine the epidemiology of human tick exposure in two Balkan countries and support targeted seasonal prevention messaging and strengthened regional surveillance. Full article

Background: Tick-borne encephalitis (TBE) virus is transmitted to humans via tick bites and occasionally via the consumption of unpasteurized milk products. According to the literature, the most important driver of TBE emergence and increase in incidence in humans is changes in human behaviour/activities. Method and principal findings: To compensate for the lack of data, expert opinions were gathered to identify the risk factors for exposure to tick bites linked to twenty-eight human activities (professional or recreational) in forests and to target prevention messages at the populations most at risk. Opinions were elicited from a total of twenty-five European experts. Seven criteria were included in the analysis for each activity: frequency, seasonality, duration of exposure, distance covered, degree of contact with vegetation, speed and average level of protection against tick bites. The activities considered to be the most at risk of exposure to tick bites are, in descending order: three occupational activities (forest monitoring activities, forestry and wood industry activities and scientific and/or analytical activities), five recreational activities and one hunting activity (mushroom picking, spending the night in the forest, hunting, naturalist activities, orienteering, and berry or fruit picking). Conclusions and significance: Prevention messages regarding tick bites could be targeted at people who engage in activities considered in this analysis to be at highest risk of exposure to tick bites. Full article

Jingmen tick virus (JMTV) is a novel flavi-like virus first identified in 2010 in Rhipicephalus microplus in the Jingmen region of Hubei Province, China and has been reported in different Asian countries, Central and South America, Africa, and Europe. Beyond ticks, JMTV has been detected in a range of other arthropods and in vertebrate hosts. In humans, JMTV has been found in patients with Crimean-Congo hemorrhagic fever in Kosovo and Turkey, and in febrile patients with a history of tick bites in China, suggesting it may be a novel human pathogen. To investigate the presence of JMTV in Italy, we developed a One-step real-time RT-PCR assay and applied it to individually screen 1150 ticks collected from northeastern, central, and southern Italy. JMTV RNA was detected in multiple tick species, including Ixodes ricinus, Rhipicephalus bursa, Rhipicephalus sanguineus s.l., Dermacentor marginatus, and Hyalomma marginatum with a prevalence ranging from 0.52% to 18.42% in questing ticks. The detection of JMTV in ticks from all surveyed areas, indicates that the virus is geographically widespread in Italy. These findings highlight the need for comprehensive surveillance strategies to identify new areas of active virus circulation and to investigate the potential impact of JMTV on public health. Full article

Ticks transmit diverse pathogens, posing significant public health threats in northeastern China; clarifying human-biting tick species and their carried pathogens is crucial for risk assessment and prevention. This study was designed as a pathogen detection and molecular epidemiological investigation. During the May-August period of each of 2023 and 2024, 232 ticks that had bitten humans were collected from a local sentinel hospital. Ticks were morphologically identified, followed by DNA extraction, semi-nested/nested PCR targeting specific genetic markers, and Sanger sequencing to detect bacterial pathogens. Four tick species were found, with Ixodes persulcatus dominant (87.9%), followed by Dermacentor silvarum (6.9%), Haemaphysalis concinna (3.5%), and Haemaphysalis japonica (1.7%). Seven bacterial pathogens were detected, including Candidatus Rickettsia tarasevichiae (35.3%) and Borreliella garinii (17.2%); 49.6% of ticks were pathogen-positive. The coinfection rate was 13.8%, most commonly Candidatus R. tarasevichiae plus B. garinii, and I. persulcatus carried all pathogens. These findings provide basic data on human-biting tick species and their bacterial pathogen spectrum in the region, serving as a reference for subsequent tick-borne disease research and targeted prevention. Full article

Haseki tick virus (HSTV) is a recently discovered virus detected in human serum following tick bites, yet its protein repertoire remains uncharacterized. In this study, we applied an integrative approach based first on membrane topology prediction, followed by AI-based structural prediction and experimental validation to annotate the structural part of the HSTV polyprotein. For the first time, we recombinantly expressed one of the putative HSTV structural protein (SP1) and determined its overall architecture using small-angle X-ray scattering (SAXS). Structural comparisons of the AI-predicted HSTV SP1 models revealed only a vague resemblance to the pestiviral Erns and Npro. The strong agreement between experimental SAXS data and the AI-predicted HSTV SP1 model supported the conclusion that HSTV SP1 adopts a distinct spatial architecture in solution, one that is not captured by existing pestiviral structures but is reliably represented by modern AI-based prediction. Our findings indicate that HSTV SP1 adopts a fold not previously observed among characterized members of the Flaviviridae family. This work establishes a methodological pipeline for characterizing highly divergent viral proteins and provides the first insights into HSTV SP1, a virus with emerging zoonotic potential. These results lay the foundation for future functional and structural studies, diagnostic development, and evolutionary analyses of atypical Flaviviridae family members. Full article

The high incidence of tick-borne diseases (particularly Lyme disease) and the challenges associated with their serious health consequences motivated us to undertake research aimed at developing robust protection against ticks. There is still no effective method for preventing or treating Lyme disease, and humans who spend time outdoors—whether for occupational or recreational purposes—remain unprotected. This paper presents an innovative design of anti-tick textile bands intended for standalone use or integration into protective trousers. The bands are designed to receive repellent-sprayed inserts and provide a barrier layer separating the chemical from the user. In the research, the protective performance of the bands was evaluated using a novel test stand specially constructed for tick repellency testing. Experiments involving live ticks demonstrated the highest effectiveness for bands incorporating an insert impregnated with 20% DEET. Two limitations were noted: peak protection was achieved approx. 15 min after DEET application, and repellent reapplication was required after three hours to maintain protection. These findings are directly relevant to protective equipment design, offering a practical solution for high-risk groups such as forestry workers. By providing an experimentally validated strategy for tick bite prevention, this work addresses an urgent need in occupational and public health. Full article

Ixodid ticks are blood-sucking ectoparasites of vertebrates. They constitute an integral part of natural foci and are responsible for the worldwide transmission of infections to humans, which can result in severe symptoms. For instance, the Tomsk region, where three abundant tick species (Dermacentor reticulatus, Ixodes pavlovskyi, I. persulcatus) occur, is an endemic area for tick-borne encephalitis virus (TBEV). An increasing number of novel infectious agents carried by ticks have been identified using metagenomic sequencing. A notable example is the Yezo virus (Orthonairovirus yezoense, YEZV), which was discovered in patients with fever after tick bites in Japan and China between 2014 and 2025. For the first time, we have performed metagenomic sequencing of the virome of ticks collected in the Tomsk region. In a sample obtained from a pool of I. pavlovskyi ticks, all three segments of the YEZV genome were detected. The phylogenetic analysis showed that the newly identified isolate formed a sister group to previously described virus isolates, indicating the presence of a new genetic variant. This study presents the first report of YEZV detection in I. pavlovskyi ticks in the Tomsk region, thereby expanding the geographical range and number of vector species for YEZV and highlighting the importance of monitoring viral agents circulating among ticks in Western Siberia. Full article

Rickettsia parkeri strain Atlantic rainforest is an emerging pathogen in Brazil, but human infections remain rarely reported. We report the first confirmed case in the municipality of Caraguatatuba on the northern coast of São Paulo State, Brazil. A 37-year-old man was bitten by an Amblyomma ovale tick while visiting a forested area. Six days later, he developed a papular skin lesion with a necrotic center at the tick bite site, accompanied by regional lymphadenopathy, myalgia, and flu-like symptoms. Ticks parasitizing both the patient and his dog were collected, along with the eschar. Two ticks were analyzed for Rickettsia isolation, and R. parkeri was successfully isolated from one infected specimen. The patient’s infection was confirmed by molecular testing through the PCR amplification of the gltA and ompA genes from an eschar inoculation sample. This represents the sixth confirmed case of rickettsiosis caused by R. parkeri in Brazil, and it reinforces the need for increased epidemiological surveillance in endemic regions for spotted fever caused by this pathogen. With the increasing recognition of R. parkeri in South America, further research is needed to better understand its transmission dynamics, clinical manifestations, and potential public health impact. Full article