Search Results (118)

Understanding the risk factors for vector-borne diseases, such as Crimean–Congo hemorrhagic fever (CCHF), is critical for effective public health strategies. This study aims to identify and map the environmental and climatic determinants influencing the distribution of Hyalomma marginatum, the primary vector of CCHF, in Türkiye, using a Multi-Criteria Decision Analysis (MCDA) approach. A rapid literature review was conducted to identify environmental, climatic, and methodological criteria used in MCDA studies on vector-borne diseases. Semi-structured interviews with local experts from Armenia, Serbia, and Türkiye provided fine-scale data on vector presence. These criteria were analyzed using the Analytic Hierarchy Process (AHP) and combined with Weighted Linear Combination (WLC) within the MCDA framework to produce risk maps for H. marginatum occurrence in Türkiye. Key environmental and climatic factors influencing H. marginatum distribution, such as temperature, humidity, vegetation, and precipitation, were identified. The MCDA analysis highlighted high-risk regions in Türkiye with elevated suitability for the vector, correlating with areas of human CCHF cases. MCDA risk maps are valuable tools for public health officials, enabling targeted surveillance and interventions. By integrating diverse environmental and climatic variables, this study enhances the understanding of CCHF dynamics and supports the development of focused control strategies. Full article

Background/Objectives: Tick-borne diseases (TBDs) are increasingly recognized as causes of both systemic and neurologic illness. While their impact on vascular health is established, their role in cerebrovascular disease remains underexplored. This review aims to synthesize clinical evidence linking TBDs with cerebrovascular events, focusing on mechanisms of injury, pathogen-specific associations, and treatment outcomes. Methods: A narrative review was conducted using Boolean keyword searches across PubMed, Scopus, EMBASE, and Web of Science. Relevant literature on ischemic and hemorrhagic stroke, cerebral vasculitis, and stroke mimics associated with TBDs was examined. The review included case reports, observational studies, and mechanistic research. Pathogen-specific data and disease characteristics were extracted and summarized. Results: Several tick-borne pathogens were associated with cerebrovascular complications. Borrelia burgdorferi was most commonly implicated and typically presented with large-vessel vasculitis. Rickettsia, Ehrlichia, and Anaplasma species caused endothelial injury through immune-mediated inflammation. Powassan virus and Crimean–Congo hemorrhagic fever virus exhibited central nervous system involvement and hemorrhagic potential. Babesia species contributed to vascular injury through thrombocytopenia and embolic complications. Neuroimaging frequently demonstrated multifocal stenoses and vessel wall inflammation. Antimicrobial treatment, particularly with doxycycline or ceftriaxone, was often effective, especially when administered early. Supportive care for stroke symptoms varied by presentation and underlying pathogen. Conclusions: Cerebrovascular disease caused by tick-borne pathogens is an underrecognized but potentially reversible condition. Despite diverse etiologies, most pathogens share a final common pathway of endothelial dysfunction. Early recognition and targeted antimicrobial therapy, combined with supportive stroke care, are essential to improving patient outcomes. Full article

Ticks from the Hyalomma genus have recently garnered public attention in countries in Northern and Central Europe, as they are transported by migratory birds and might have established stable populations due to climate warming. The main threat associated with Hyalomma ticks is their ability to transmit Crimean–Congo hemorrhagic fever virus (CCHFV), which can be fatal in up to 40% of cases. Here, we collected Hyalomma ticks from migratory birds during annual ringing actions in the spring seasons of 2023 and 2024. Four ticks were found on birds from the Acrocephalus genus and two on Hippolais icterina. The ticks were examined for the presence of Rickettsia spp., Babesia microti, Babesia divergens, Coxiella burnetii, Borreliella burgdorferi (s. l.), Anaplasma phagocytophilum, West Nile virus, and CCHF virus (CCHFV). The collected H. rufipes specimens were negative for tested pathogens, except for two ticks collected in 2024, which were positive for Rickettsia aeschlimannii. The data show that Hyalomma ticks are efficiently transported on birds preferring reedbeds or deciduous trees. The possibility of the occurrence of CCHF or rickettsiosis (induced by R. aeschlimannii) is currently assessed as low. Nevertheless, we have shown the transfer of Hyalomma ticks to Poland and indicated the need for careful future epidemiological monitoring of the presence of Hyalomma ticks. Full article

Crimean–Congo hemorrhagic fever virus (CCHF-V) and Ebola virus are lethal pathogens that cause widespread outbreaks of hemorrhagic fever. Both diseases can be transmitted through contact with the bodily fluids of infected individuals, but as an arbovirus, CCHF-V is primarily transmitted through tick bites. Both of these viruses are classified as Risk Group 4 due to the appreciable health threat they pose. To date, there are few effective treatments available to combat these deadly hemorrhagic fevers. Consequently, identifying and characterizing ion channels (viroporins) encoded in the viral genomes may lead to potential targeted drug development. Therefore, using bacteria-based genetic assays, two viroporin candidates from CCHF-V and Ebola have been examined, and their proposed structures have been modeled to aid in further drug discovery. The results indicate that CCHF-V-gp exhibits channel activity, which is indistinguishable from established viroporins found in other viruses. In contrast, our experimental approach was unable to uncover a viroporin candidate in the Ebola virus. Full article

Crimean–Congo hemorrhagic fever (CCHF) is a zoonotic viral disease endemic to parts of Africa, Asia and southeastern Europe. Bulgaria is one of the few European countries with the consistent annual reporting of human CCHF cases. This study provides a descriptive overview of 24 confirmed CCHF cases in Bulgaria between 2015 and 2024. Laboratory confirmation was performed by an enzyme-linked immunosorbent assay (ELISA) and/or real-time reverse transcriptase polymerase chain reaction (RT-qPCR) testing. Common findings included fever, fatigue, gastrointestinal symptoms, thrombocytopenia, leukopenia, liver dysfunction and coagulopathy. Two fatal cases were recorded. Two samples collected in 2016 and 2024 were subjected to whole-genome sequencing. Phylogenetic analysis showed that both strains clustered within the Turkish branch of the Europe 1 genotype and shared high genetic similarity with previous Bulgarian strains, as well as strains from neighboring countries. These findings suggest the long-term persistence of a genetically stable viral lineage in the region. Continuous molecular and clinical surveillance is necessary to monitor the evolution and public health impact of CCHFV in endemic areas. 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

The Crimean–Congo hemorrhagic fever virus (CCHFV) is a single-stranded, segmented RNA virus belonging to the Nairoviridae family, and it is rapidly expanding across Africa, Asia, and southern Europe, probably favored by climate change and livestock trade. Its fatality rate in humans reaches up to 40%, and there is currently no specific treatment or vaccine available. Therefore, the development of therapies against CCHFV is essential, and their design requires understanding of the molecular evolution and genetic distribution of the virus. Motivated by these concerns, we present a comprehensive review of the molecular evolution, genetic characterization, and phylogeography of CCHFV, and we discuss their potential implications for therapeutic design. Specifically, we describe the virus’s capacity to increase its genetic diversity through numerous mutations, recombination events, and genomic reassortments, which affect fundamental viral functions such as RNA binding, host–virus interactions, viral entry, and polymerase activity. We also assess the presence of temporal heterogeneous rates of evolution and molecular adaptation among CCHFV coding regions, where purifying selection is generally predominant but diversifying selection is observed in molecular regions associated with host adaptation and transmission. We emphasize the importance of understanding the complex molecular evolution of CCHFV for the rational design of therapies and highlight the need for efforts in surveillance, evolutionary prediction, and therapeutic development. Full article

Research on highly pathogenic biosafety level 4 (BSL-4) viruses that are classified as Select Agents involves transferring inactivated materials to lower containment levels for further analysis. Compliance with Select Agent and BSL-4 safety regulations necessitates the validation and verification of inactivation procedures. To streamline this process, it would be beneficial to use surrogate BSL-2 viruses for inactivation studies. This not only simplifies BSL-4 work but also enables the testing and validation of inactivation procedures in research facilities that lack access to high-containment laboratories yet may receive samples containing highly pathogenic viruses that require efficient and complete inactivation. In this study, we used Hazara virus (HAZV) as a surrogate virus for Crimean–Congo hemorrhagic fever virus to show the efficacy of various inactivation methods. We demonstrate the successful inactivation of HAZV using TRIzol/TRIzol LS and aldehyde fixation. Importantly, the parameters of the aldehyde inactivation of cell pellets differed from those of the monolayers, highlighting the importance of inactivation validation. As part of this study, we also defined specific criteria that must be met by a BSL-2 virus to be used as a surrogate for a closely related BSL-4 virus. Defining these criteria helps identify suitable nonpathogenic surrogates for developing inactivation procedures for highly pathogenic viruses. Full article

Tick-borne viruses (TBVs), notably Orthonairovirus haemorrhagiae (Crimean–Congo hemorrhagic fever virus, CCHFV), are emerging global health threats intensified by climate change. Rising temperatures and altered precipitation patterns are expanding the habitats of key tick vectors, increasing their survival and reproductive success. The African continent is characterized by many different climatic zones, and climatic shifts have increased or changed CCHFV transmission patterns, becoming greater risk to humans and livestock. Beyond Africa, CCHFV spread in Europe, the Middle East, and Asia and has been facilitated by factors such as livestock movement, deforestation, and migratory birds. Climate-driven shifts in tick seasonality, behavior, and vector competence may further enhance viral transmission. Addressing these challenges requires integrated responses, including enhanced surveillance, predictive modeling, and climate-adaptive vector control strategies. A One Health approach—linking environmental, animal, and human health domains—is essential. Innovative strategies such as anti-tick vaccines and sustainable vector control methods offer promise in reducing the burden of these diseases. Proactive, collaborative efforts at regional and international levels are crucial in tackling this growing public health challenge. Full article

This research addresses IL-28B gene polymorphisms (rs12979860 and rs8099917) to determine their association with HTLV-1-related diseases; it aims to compare genotypic frequencies to identify predisposition or protection, considering population, disease, and controls. Given HTLV-1’s impact on immunity, this study seeks biomarkers for early diagnosis and intervention. A systematic search met inclusion criteria, such as open access bibliographic and experimental studies published in English between 2010 and 2024, and genetic factors linked to susceptibility to pathologies. Regarding exclusion criteria, bibliographic or experimental studies in organisms other than humans, unofficial sources, non-indexed journals, and scientific articles in languages other than English were ruled out. Statistical data analyses were assessed using meta-analysis, including forest plot and Q test of heterogeneity based on the I² statistics. The analyzed data indicate associations between genotypes, such as CT, GG, CC, and TT of the rs12979890 and rs8099917 polymorphisms and the predisposition to various diseases, such as HCV, arthropathy, HAM/TSP, cytomegalovirus and Crimean–Congo hemorrhagic fever associated with HTLV-1; however, the observed inconsistencies, such as high heterogeneity, and deficiency of related information limit the consolidation of the findings. Further research is needed to clarify IL-28B genotype interactions and disease susceptibility in HTLV-1 infections. Full article

Handling cultured isolates and clinical, environmental, or wildlife surveillance samples containing Risk Group 3 and 4 pathogens presents considerable biosafety challenges in minimizing human exposure during processing and transport. Safe handling typically requires high- or maximum-containment facilities, demanding substantial logistical planning and resources. We evaluated PrimeStore Molecular Transport Medium (PS-MTM), a guanidine-based solution created to kill pathogens and preserve nucleic acids at ambient temperatures, for inactivating Crimean-Congo hemorrhagic fever, eastern equine encephalitis, Ebola, Hendra, Japanese encephalitis, Lassa, Marburg, Nipah, Rift Valley fever, and West Nile viruses. To mimic diagnostic conditions, human whole blood spiked with any of these viruses was incubated with PS-MTM for 20-, 30-, or 60-min. Samples with titers up to 10⁷ PFU/mL exposed to PS-MTM at all time points resulted in complete loss of infectivity judged by plaque assays. A 30-min incubation provided a 50% safety margin over the minimum inactivation time and was used for quantification with the tissue culture infectious dose (TCID₅₀) assay, enabling evaluation of PS-MTM’s activity for viruses that do or do not produce well-defined plaques. Results confirmed that PS-MTM inactivated all tested viruses at titers up to 10⁷ TCID₅₀/mL, underscoring its reliability for enhancing biosafety in diagnostics, outbreak management, and surveillance. Full article

Crimean–Congo hemorrhagic fever virus (CCHFV) causes severe or fatal infections in humans and is geographically widespread. The virus has coevolved with its tick vectors, establishing persistent infections critical to its transmission. This study explored the mechanisms underpinning these persistent infections, using tick cell lines and the Hazara virus (HAZV) as a biosafety level 2 (BSL-2) model for CCHFV. Initially, an RT-qPCR protocol was developed to detect HAZV in tick cells. The study then focused on the production of virus-derived DNA (vDNAs) by tick cells as a defensive response to infection. These vDNAs regulate viral particle production, enabling tick cells to maintain viability and establish persistent infections. The experiments characterized vDNAs production, viral titers, and subcellular localization, and they examined the effect of the reverse transcriptase inhibitor azidothymidine triphosphate (AZT). The results showed that all tested tick cell lines supported HAZV replication, achieving persistent infections without cytopathic effects. vDNAs was detected in both the cytoplasm and nucleus, and its formation was dependent on HAZV infection. Importantly, vDNAs presence was linked to infection persistence; cells treated with AZT exhibited a marked reduction in vDNAs production and an associated increase in viral particle production, which correlated with higher cell death. These findings underscore the critical role of vDNAs in balancing viral replication and promoting long-term cell survival in tick cells, highlighting their importance in the coevolution of tick-borne viruses and their vectors. Full article

Crimean–Congo hemorrhagic fever (CCHF) is a tick-borne zoonotic disease, causing clinical presentations ranging from asymptomatic infection to fatal viral hemorrhagic fever. Throughout the course of CCHF, the levels of certain biomarkers, such as platelets (PLTs), white blood cells (WBCs), C-reactive protein (CRP), and interleukin-6 (IL-6), may vary, decreasing below or rising above normal limits. This study aimed to investigate the role of parameters such as WBC/PLT, WBC/IL-6, WBC/CRP, and WBC/D-dimer ratios in predicting disease prognosis in patients diagnosed with CCHF. The study population consisted of 60 CCHF patients and 30 controls. Statistically significant differences were observed in hemoglobin (HGB), PLT, WBC, activated partial thromboplastin time (aPTT), international normalized ratio (INR), fibrinogen, and d-dimer values between the patients and controls. Statistically significant differences were observed in WBC/aPTT, WBC/fibrinogen, WBC/D-dimer, and WBC/IL-6 values between the patient and control groups. WBC/INR and WBC/fibrinogen values were lower in fatal cases compared to survivors. WBC/D-dimer and WBC/IL-6 values, on the other hand, were higher in fatal cases compared to survivors. In patients requiring intensive care unit (ICU), WBC/PLT, WBC/INR, WBC/aPTT, and WBC/fibrinogen values were higher compared to those who did not. However, WBC/D-dimer and WBC/IL-6 values were lower in patients requiring ICU compared to those who did not. Full article

Background/Objectives: Crimean–Congo hemorrhagic fever virus (CCHFV) is an emerging, widely distributed zoonotic tick-borne pathogen. The virus causes severe disease in humans, and numerous wild and domestic animals act as reservoirs of it. Unfortunately, there are no effective therapies or safe vaccines commercialized nowadays for this particular virus. As CCHF (Crimean–Congo hemorrhagic fever) is a serious threat to public health, there is an urgent need to investigate the development of safe and effective vaccination strategies further. Methods: In this work, we have employed two immunization platforms based on protein nanoparticles and a modified vaccinia Ankara (MVA) viral vector using the nucleoprotein (NP) as the target antigen. The humoral and cellular immune responses were characterized by ELISA, ICS, and cytokine measurement. Results: This work shows that a single dose of the vaccine candidates was not as immunogenic as the heterologous vaccination using nanoparticles and MVA. A prime with NP nanoparticles (NS-NP) and a boost with MVA-expressing NP were capable of triggering significant levels of humoral and cellular immune responses against CCHFV in mice. Conclusions: Our study shows that the NS-NP/MVA-NP vaccination strategy effectively elicits a robust humoral and cellular immune response in a mouse model, emphasizing its potential as a protective approach against CCHFV lineages. Full article

Crimean–Congo hemorrhagic fever (CCHF) is a tick-borne zoonotic viral disease prevalent in Africa. While infection is asymptomatic in animals, it can cause severe illness with hemorrhagic manifestations and high mortality rates in humans. This study aimed to determine the seroprevalence and potential risk factors of CCHF in wild (rodents, birds) and domestic (cattle, horses) animals in Benin. A cross-sectional study was carried out from 2022 to 2024 with the assistance of cattle breeders, hunters, farmers and bushmeat sellers in 15 districts found in three agroecological zones in the country. A total of 366 serum samples were analyzed, comprising 254 collected from wild animals and 112 from domestic animals. Among the wild animals tested, 1.18% (95% CI: 0.31–3.70; n = 3) were seropositive for antibodies against CCHF virus (CCHFV). The seroprevalence rates were 3.7% (95% CI: 0.19–20.89) in squirrels, 5.88% (95% CI: 0.31–30.76) in hares and 1.19% (95% CI: 0.06–7.38) in giant rats. In domestic animals, anti-CCHFV antibodies were detected in 38 of the 112 samples, resulting in an overall seroprevalence of 33.93% (95% CI: 25.42–43.56). Specifically, antibodies were identified in 34 out of 81 cattle (41.98%, 95% CI: 31.26–53.46) and 4 out of 24 horses (16.67%, 95% CI: 5.48–38.19). No positive samples were reported in pigeons. This study provides the first seroprevalence data on CCHF in wild and domestic animals in Benin. It highlights the risk and epidemiological dynamics of the disease and underscores the need for further investigations into tick vectors and human populations. Full article