Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “tick-borne virus”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed2025

Surveillance of tick-borne viruses in the border regions of the Tumen River Basin: Co-circulation in ticks and livestock.

BACKGROUND: The unique eco-geographical patterns and climatic conditions of the China-Tumen River border region, combined with frequent cross-border tourism and trade activities, collectively establish this area as a recognized hotspot for tick-borne disease outbreaks. However, critical knowledge gaps persist regarding the eco-epidemiology of emerging tick-borne viruses and the distribution of their potential reservoir hosts within this trinational ecosystem spanning China, North Korea, and Russia. METHODS: We collected a total of 2,004 ticks from the study area, along with blood samples obtained from 42 sheep and 45 cattle. Following viral metagenomic analysis of the ticks, dual verification of target pathogens in all samples was performed using qRT-PCR and RT-PCR assays. Phylogenetic trees were constructed and nucleotide sequences were analyzed to delineate relationships between the obtained virus strains and reference sequences. RESULTS: Viral metagenomics identified three viruses in ticks: Dabieshan tick virus (DBTV), Songling virus (SGLV), and Yanggou tick virus (YGTV). PCR analysis detected DBTV exclusively in Hunchun ticks (minimum infection rates, MIR:4.73%) and YGTV in Antu specimens (MIR:0.97%). Conversely, SGLV was detected in ticks from all four regions, with MIR of 1.68% (Helong), 0.74% (Hunchun), 1.61% (Antu), and 4.79% (Longjing). Concurrently, SGLV was detected in 19 sheep blood samples from Longjing, yielding a positivity rate of 45.24%, while YGTV was identified in 13 cattle blood samples from Antu, with a positivity rate of 28.89%. Phylogenetically, the DBTV strain clustered with previously reported DBTV and Yongjia tick virus 1 isolates. Sheep-derived SGLV strains shared close evolutionary ties with tick-borne SGLV, whereas YGTV from cattle and ticks formed a distinct cluster with Russian strains but diverged into two branches from Chinese variants, suggesting evolutionary instability. CONCLUSION: These findings address critical knowledge gaps in the transmission dynamics and genetic diversity of emerging arboviruses while providing vital insights for developing cross-border surveillance strategies with significant public health implications.

Animals↗
PubMed1977

Concentration and purification of tick-borne encephalitis virus grown in suspensions of chick embryo cells.

Tick-borne encephalitis (TBE) virus grown in suspensions of chick embryo cells was precipitated by various concentrations of polyethylene glycol (PEG) 6000. Quantitative recovery was obtained at PEG concentrations of 5% and higher. As precipitation of contaminating non-viral protein increases with increasing PEG concentrations, best results with respect to purity and recovery were obtained at 5% PEG 6000. Analysis of virus concentrates by rate zonal centrifugation revealed two peaks--rapidly sedimenting haemagglutinin (RHA) associated with infectivity and slowly sedimenting haemagglutinin (SHA)--characteristic of Flaviviruses. Purification factors after PEG precipitation followed by rate zonal centrifugation in sucrose density gradients ranged from 50 to 200 for HA activity and from 40 to 50 for infectivity.

Animals↗
PubMed2024

A series of patients infected with the emerging tick-borne Yezo virus in China: an active surveillance and genomic analysis.

BACKGROUND: Yezo virus (YEZV) is an emerging tick-borne pathogen, which was initially reported in Japan in 2021. Only one patient had been reported in China so far. We aimed to describe the epidemiological, clinical, and laboratory findings of a series of patients, and to characterise the viral genomes of YEZV. METHODS: In this active surveillance and genomic analysis, we conducted active surveillance at Mudanjiang Forestry Central Hospital, Heilongjiang Province of northeast China. Participants were eligible for inclusion if they sought medical care for a recent tick bite between May 1 and July 31, in 2022 and 2023, and between May 1 and July 10, in 2024. We collected sera from participants to detect YEZV infection by meta-transcriptomic sequencing, real-time RT-PCR, and indirect immunofluorescence assay. We isolated YEZV by cell culture and characterised the pathogen by morphological and phylogenetic analyses. FINDINGS: A series of 18 patients with YEZV infection (12 male and six female; median age 53 years, IQR 45-60) were identified among 988 participants. The patients presented with fever (18 patients, 100%), headache (ten patients, 56%), dizziness (nine patients, 50%), malaise (three patients, 17%), lumbago (three patients, 17%), and cough (three patients, 17%). Nine (50%) patients had rash around the tick bite site and four (22%) had lymphadenopathy. Nine (50%) patients had gastrointestinal symptoms, and five (28%) had neurological symptoms. We observed leukopenia in ten (63%) and thrombocytopenia in five (31%) of 16 assessed patients. Elevated hepatic transaminase concentrations were identified in 13 (72%) of all 18 patients, lactate dehydrogenase or α-hydroxybutyric dehydrogenase in nine (50%), serum amyloid protein A in 13 (72%), and hypersensitive C-reactive protein in ten (56%). Eight (7%) of 119 Ixodes persulcatus ticks removed from participants were positive for YEZV. Three YEZV strains were isolated from the sera of patients. Ten viral genomes were obtained from five patients, a blood-sucking I persulcatus removed from a participant, and four host-questing tick samples collected in the areas where patients were identified or in the adjacent region. Phylogenetic analyses revealed that YEZVs in either patients or ticks were divided into two clades, each with distinct mutations. INTERPRETATION: Awareness of YEZV infection is important and clinicians should consider the virus when diagnosing patients with suitable symptoms. FUNDING: National Key Research and Development Program of China. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

Humans↗
PubMed2026

Field-isolate recombinant tick-borne encephalitis viruses define reporter-stability guidelines for antiviral testing in flaviviruses.

As arthropod-borne viruses continue to threaten populations globally, there is a pressing need for experimental systems that enable rapid antiviral discovery. Reverse-genetics platforms producing recombinant reporter orthoflaviviruses have been developed to address this gap. Here, we present two new recombinant tick-borne encephalitis viruses (TBEVrec) generated on a European-subtype Haselmühl Tiho1 isolate backbone. A reporter gene, either eGFP or Nluc, was inserted in the capsid-coding region of the genome downstream of the capsid RNA regulatory signal and separated from the complete viral polyprotein by a 2A self-cleaving peptide. TBEVrec was better rescued using the circular polymerase extension reaction (CPER) than with the infectious subgenomic amplicon (ISA) method. TBEVrec replicated efficiently in relevant human cell lines, with comparable replication to wild-type TBEV in a neuronal cell line and moderately reduced titers and RNA levels in immune-derived cell lines. Using either eGFP or Nluc, we illustrate how TBEVrec enabled high-content RNAi screening, highlighting Nucleolin and PRKD1 as potential TBEV host factors, and drug testing on a benchtop plate reader. Nanopore sequencing of the eGFP insert revealed that the reporter is excised without affecting flanking regions. Comparative analysis of eGFP and Nluc further shows that this instability is time- and cell type-dependent, and that Nluc is comparatively more stable. From these observations, we outline safeguards and design principles that are broadly applicable both to the rescue of existing constructs and to the design of future recombinant reporter virus platforms.

CPER↗
PubMed2024

Identification and epidemiological study of an uncultured flavivirus from ticks using viral metagenomics and pseudoinfectious viral particles.

During their blood-feeding process, ticks are known to transmit various viruses to vertebrates, including humans. Recent viral metagenomic analyses using next-generation sequencing (NGS) have revealed that blood-feeding arthropods like ticks harbor a large diversity of viruses. However, many of these viruses have not been isolated or cultured, and their basic characteristics remain unknown. This study aimed to present the identification of a difficult-to-culture virus in ticks using NGS and to understand its epidemic dynamics using molecular biology techniques. During routine tick-borne virus surveillance in Japan, an unknown flaviviral sequence was detected via virome analysis of host-questing ticks. Similar viral sequences have been detected in the sera of sika deer and wild boars in Japan, and this virus was tentatively named the Saruyama virus (SAYAV). Because SAYAV did not propagate in any cultured cells tested, single-round infectious virus particles (SRIP) were generated based on its structural protein gene sequence utilizing a yellow fever virus-based replicon system to understand its nationwide endemic status. Seroepidemiological studies using SRIP as antigens have demonstrated the presence of neutralizing antibodies against SAYAV in sika deer and wild boar captured at several locations in Japan, suggesting that SAYAV is endemic throughout Japan. Phylogenetic analyses have revealed that SAYAV forms a sister clade with the Orthoflavivirus genus, which includes important mosquito- and tick-borne pathogenic viruses. This shows that SAYAV evolved into a lineage independent of the known orthoflaviviruses. This study demonstrates a unique approach for understanding the epidemiology of uncultured viruses by combining viral metagenomics and pseudoinfectious viral particles.

Animals↗
PubMed2026

Metagenomic profiling of tick-borne viromes across four ecologically diverse provinces in China.

Ticks are important vectors of emerging viruses, and China's ecological landscapes may influence the transmission dynamics of tick-borne viruses (TBV). In 2021, a total of 2867 ticks collected from Inner Mongolia, Hebei, Hunan, and Hainan provinces were subjected to metagenomic sequencing to characterize TBV diversity. A total of eleven TBVs were identified, comprising three members of the family Phenuiviridae (severe fever with thrombocytopenia syndrome virus, Lihan tick virus, Dabieshan tick virus), three belonging to Nairoviridae (Huangpi tick virus 1, Shanxi tick virus 2, Henan tick virus), one in Chuviridae (Wuhan tick virus 2), one in Rhabdoviridaes (Wuhan tick virus 1), and three unclassified viruses (Hubei tick virus 2, Bole tick virus 4, and Tacheng tick virus 7). Viral composition varied significantly across tick species and geographic regions, with phylogenetic analysis revealing distinct regional clustering patterns. Notably, Lihan tick virus was detected for the first time in Hunan Province, Bole tick virus 4 was identified in argasid ticks from Inner Mongolia for the first time, and a novel lineage of severe fever with thrombocytopenia syndrome virus was discovered in Shijiazhuang, Hubei Province. These findings underscore substantial TBV diversity shaped by tick species and geographic origin, emphasizing the necessity for ongoing surveillance to guide the development of targeted prevention and control strategies.

Animals↗
PubMed2025

The Single Amino Acid Change of R516K Enables Efficient Generation of Vesicular Stomatitis Virus-Based Crimean-Congo Hemorrhagic Fever Reporter Virus.

Crimean-Congo hemorrhagic fever virus (CCHFV) is a medically important tick-borne virus, causing severe hemorrhagic diseases in humans. There are no approved vaccines and therapeutics for CCHFV infection. The study of CCHFV authentic virus requires biosafety level 3 facilities, hindering the research and development of antivirals. Here we report the generation of a recombinant vesicular stomatitis virus (VSV) bearing both CCHFV glycoprotein precursor (GPC) and EGFP reporter (rVSV-CCHFV-GFP). We also find that the acquisition of an unexpected single R516K mutation in the GPC protein enables the packaging of high-titer pseudotyped particles. The replication-competent rVSV-CCHFV-GFP reporter virus resembles the entry properties of the authentic virus and allows for rapid assessment of susceptible cell lines, neutralizing antibodies, and host entry factors such as heparan sulfate in fluorescence-based assays. This study provides a valuable strategy for packaging of high-titer CCHFV pseudovirus, and the tool generated here can be served for the identification and evaluation of countermeasures against the cell entry of CCHFV.

Hemorrhagic Fever Virus, Crimean-Congo↗
PubMed2026

Emerging tick-borne viral diseases in East Asia: pathology-driven insights into pathogenesis and disease causality.

SUMMARYTick-borne viral infections have emerged as a significant and growing public health concern. In East Asia, severe fever with thrombocytopenia syndrome (SFTS) has served as a prototypical disease in which pathological analyses have substantially advanced the understanding of disease pathogenesis. SFTS is characterized by profound immune dysregulation driven by viral tropism for plasmablast-lineage B cells, leading to cytokine storm and hemophagocytic syndrome. Complementary analyses of human clinical specimens and experimental animal models, including cats and ferrets, have provided critical insights into the immunopathogenesis of SFTS. The recent identification of additional tick-borne viruses, including Oz virus (OZV), Yezo virus (YEZV), and Alongshan virus (ALSV), has further expanded the spectrum of emerging infections in this region. Notably, pathological investigation of a fatal human case of OZV infection demonstrated direct viral localization within cardiomyocytes, establishing a causal link between infection and fulminant myocarditis and highlighting a distinct organ-specific pathogenic mechanism. Despite the advances in genomic technologies that enable rapid detection of novel viruses, establishing causal relationships between viral presence and disease remains a major challenge. Tissue-based pathological approaches, particularly in situ localization of viral components, are, therefore, essential for defining disease mechanisms and confirming etiological roles. This review provides a comprehensive synthesis of tick-borne viral infections in East Asia, with particular emphasis on Japan, integrating pathological, virological, and clinical perspectives. It also identifies key knowledge gaps and underscores the importance of a synergistic One Health framework that incorporates both human and veterinary pathology to advance the understanding and control of these emerging diseases.

One Health↗
PubMed2026

Evolutionary history of Jamestown Canyon virus reveals complex multi-vector ecology.

Jamestown Canyon virus (JCV) is a historically understudied mosquito-borne virus of increasing concern in North America. We generated 658 whole-genome JCV sequences from northeast United States, including 84% (500/597) of all JCV-positive mosquitoes detected in Connecticut from 1997 to 2022. Then, we applied phylodynamic methods to demonstrate how mosquito phenology structures the maintenance and evolution of JCV. Our phylogenetic analyses estimate that JCV was introduced in the Northeast by at least the early 1700s, and the primary introductions of lineages A and B into Connecticut occurred during the mid-1800s to mid-1900s. Further, we estimate that JCV evolves at a rate of ∼3 × 10-5 substitutions per site per year (s/s/y), making it one of the slowest-evolving known RNA viruses, because the virus spends ∼10 months per year in evolutionary stasis while overwintering in mosquito eggs. To investigate ecological drivers of JCV spread in Connecticut, we paired discrete trait and continuous phylogeographic reconstructions with mosquito surveillance data. We estimate that JCV has a low diffusion rate of ∼30-60 km2/year, which is more similar to slow-moving tick-borne viruses than to other mosquito-borne viruses. We found that univoltine Aedes mosquitoes were likely to maintain the virus across years through overwintering in eggs, accounting for its slow evolution and dispersal, while multivoltine mosquitoes contributed to periodic bursts of spatial diffusion and amplification within seasons. We demonstrate the utility of dense sequencing and phylodynamics to disentangle complex transmission cycles, offering a framework for rapidly advancing our evolutionary and ecological knowledge of understudied viruses.

Animals↗
PubMed1976

Non-infectious tick-borne encephalitis antigen.

After formalin treatment of sucrose-acetone antigens, prepared from different tick-borne encephalitis (TBE) virus strains, their haemagglutination (HA) activity was preserved or even higher than that of untreated antigens. Formalin-treated TBE antigen was non-infectious and thus may be recommended for routine work to avoid laboratory infections.

Animals↗
PubMed2025

Establishment of reverse genetics systems for Colorado tick fever virus.

The Colorado tick fever virus (CTFV), which has 12-segmented double-stranded RNA genomes, is a pathogenic arbovirus that causes severe diseases in humans. However, little progress has been made in the analysis of replication mechanisms and pathogenicity. This virological constraint is due to the absence of a reverse genetics system for CTFV; therefore, we aimed to establish the system. Initially, the efficacy of CTFV replication was investigated in various cell lines. CTFV was found to grow in many cell types derived from different hosts and organs. Subsequently, BHK-T7 cells stably expressing T7 RNA polymerase were transfected with plasmids encoding each of the 12 CTFV gene segments, expression plasmids encoding all CTFV proteins, and a vaccinia virus RNA-capping enzyme. Following transfection, the cells were co-cultured with Vero or HeLa cells. Using this system, we rescued monoreassortants and recombinant viruses harboring peptide-tagged viral proteins. Furthermore, an improved system using Expi293F cells expressing T7 RNA polymerase was established, which enabled the generation of recombinant reporter CTFVs. In conclusion, these reverse genetics systems for CTFV will greatly contribute to the understanding of viral replication mechanisms, pathogenesis, and transmission, ultimately facilitating the development of rational treatments and candidate vaccines.

Animals↗
PubMed2026

Widespread circulation of Alongshan virus in Austria and serological evidence for infection in humans: a nationwide molecular and serological observational study.

BACKGROUND: Alongshan virus, a segmented RNA virus in the Jingmenvirus group of flaviviruses, was first identified in 2017 in China in patients with tick-borne encephalitis-like illness. Alongshan virus has since been detected in ticks and mammals in several European countries. In this study, we aimed to characterise the temporal and geographical distribution of Alongshan virus in Austria through nationwide tick surveillance combined with serological and molecular screening in individuals with suspected tick-borne encephalitis or tick exposure. METHODS: In this nationwide molecular and serological observational study, we conducted a PCR-based screening of ticks collected across Austria in 2024, using flagging, animal hosts, and citizen submissions. We also collated genomic data from stored nucleic acid extracts from ticks collected in Austria in 2005 and 2013 in previous surveillance studies and stored extracts of paired tick-human samples collected between 2015 and 2018. Alongshan virus-positive tick samples were subjected to whole-genome sequencing and phylogenetic analysis. In addition to tick samples, blood samples from Austrian patients with reported tick bite or suspected tick-borne encephalitis, submitted to the National Reference Center for Human Arbovirus Infections, Austria, were screened for Alongshan virus infection and subjected to serological and molecular testing. FINDINGS: 2952 ticks were collected between Feb 1, 2024, and Dec 6, 2024, from 29 (83%) of 35 NUTS-3 regions in Austria; the median detection rate for Alongshan virus was 1·2% (IQR 0·4-3·5). In addition, 1816 archived tick samples were analysed, with three testing positive for Alongshan virus. For the virus-positive samples, phylogenetic analysis showed that sequences from Austria grouped within the European clade, with Austrian sequences from the same region showing high sequence similarity. 1361 human serum samples collected between March 1, 2023, and May 16, 2025, were assessed for anti-Alongshan virus IgG antibodies. Two individuals had high antibody titres against Alongshan virus proteins VP1a and VP2. INTERPRETATION: Our study shows detection of Alongshan virus in archived tick samples dating back to 2005, representing the earliest documented occurrence of the virus to date and suggesting that Alongshan virus has been circulating in Austria for at least two decades. The detection of Alongshan virus-specific antibody titres in two individuals suggests past infection and previously unrecognised exposure. These results highlight the need for continued molecular surveillance of tick populations and serological monitoring in humans to define the epidemiology and public health relevance of Alongshan virus in Europe. FUNDING: One Health surveillance and Vector monitoring for cross-border pathogens (OH SURVector) and UNITED4Surveillance.

Adolescent↗
PubMed2025

Viral hijacking of host DDX60 promotes Crimean-Congo haemorrhagic fever virus replication via G-quadruplex unwinding.

Crimean-Congo haemorrhagic fever virus (CCHFV) is the most prevalent tick-borne zoonotic bunyavirus, causing severe hemorrhagic fever and fatality in humans. Currently, the absence of approved vaccines or therapeutics for CCHFV infection necessitates the development of innovative therapeutic strategies. Here, we identify a guanine (G)-rich sequence located within the mRNA of the glycoprotein precursor in the medium (M) segment of the CCHFV genome, designated as M-PQS-1664(+). M-PQS-1664(+) can form stable G-quadruplex (G4) structure and functions as a negative regulatory element for viral replication. Host DDX60 is up-regulated in response to CCHFV infection, thereby it is hijacked to unwind M-PQS-1664(+) G4 for facilitating viral replication. The FDA-approved drug Cepharanthine (CEP), which competes with DDX60 to specifically stabilize M-PQS-1664(+) G4 without a global induction of host cellular G4s formation, exhibits remarkable antiviral activity in vitro and in vivo. More importantly, CEP possesses antiviral activity (50% inhibitory concentration ~ 0.2 μM) that having ~ 88 × the potency of ribavirin. Our findings underscore the CCHFV G4s as a promising target for drug development and highlight the significant potential of CEP in combating CCHFV.

Hemorrhagic Fever Virus, Crimean-Congo↗
PubMed2025

A new potential mosquito-borne virus: detection of Human-derived Jingmenvirus in several-species of mosquitoes from Yaoundé, Cameroon.

BACKGROUND: Tick-borne Jingmenviruses are becoming an increasing arbovirus concern due to the rising number of reported infections in humans and animals, as well as their wide geographic distribution. The involvement of other hematophagous arthropods as vectors of Jingmenviruses is still unknown. METHODS: Mosquitoes were sampled in two different biotopes in Cameroon (Yaoundé and Garoua) during the rainy and the dry seasons in 2022 and 2023. Metatranscriptomics Next Generation Sequencing was conducted using Illumina technology. Viral sequences detection revealed the presence of several contigs with high sequence identity to a human-derived Jingmenvirus (HdJV) previously discovered in plasma from an individual from Yaoundé, Cameroon. A draft viral genome was constituted for each Jingmenvirus-positive samples. Maximum likelihood phylogenetic reconstructions were used to position mosquito-associated viruses within the diversity of Jingmenviruses. Statistical analyses were conducted to estimate the prevalence of infected mosquitoes and the effect of different variables (region, season, year, mosquito species) on Jingmenvirus detection. RESULTS: HdJV was identified during the dry and the rainy seasons in 4 species of mosquitoes: Aedes albopictus, Culex quinquefasciatus and Culex wansoni from Yaoundé, and Anopheles gambiae s.l. from Garoua. The overall prevalence of HdJV-infected mosquitoes was estimated to 0.90% [0.41-1.69]; and the unique variable significantly associated with HdJV detection was the sampling area: Yaoundé showed the highest prevalence (2.29% [0.95-4.68]) compared to Garoua (0.18% [0.01-0.79]). Mosquito-associated Jingmenviruses shared a high nucleotide identity (between 98.64-100% according to the segment) and clustered in the same clade in the phylogenetic analysis, that they belong to the same viral species circulating in different mosquito species. The viral genome shared between 96.4% and 98.9% nucleotide identity with a HdJV detected in the plasma of a patient suffering from febrile illness originating from the same area, suggesting the possible involvement of mosquitoes as vectors of arboviral Jingmenviruses in human infections. CONCLUSIONS: This finding provides new insights into the ecology and transmission dynamics of Jingmenviruses, highlighting mosquitoes as potential vectors, alongside ticks, in the zoonotic transmission of this virus group.

Jingmenvirus↗
PubMed2026

Metagenomic analysis of the midgut microbiome in Dermacentor abaensis ticks at different feeding states.

Ticks are blood-sucking ectoparasites of humans and animals, ranking second only to mosquitoes as vectors of diseases. Dermacentor abaensis is distributed in Sichuan, Qinghai, and Gansu, China. Because D. abaensis harbors several pathogens, it poses a threat to public health and livestock production. However, the midgut microbiota of D. abaensis at distinct feeding states remains poorly characterized. Adult D. abaensis ticks at various feeding states were collected from yaks in Gansu Province, China. Genomic DNA was extracted from midguts and midgut contents of unfed, partially fed, and fully engorged female D. abaensis. A metagenomic sequencing approach was employed to profile the midgut microflora among three groups. A total of 83 phyla, 908 genera, and 1857 species were annotated across the three groups. At the phylum level, Pseudomonadota, Mucoromycota, and Ascomycota were the most abundant. At the species level, common bacterial species such as Klebsiella pneumoniae and Anaplasma phagocytophilum, alongside viruses and eukaryotes, were detected in all three groups. Unique microorganisms were also observed in each group: unfed (n = 305), partially fed (n = 59), and fully engorged (n = 20). Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis suggested that the D. abaensis microbiome contains a relatively high abundance of functional genes involved in lipid and amino acid metabolism across the three different feeding states. These findings indicate that while core microbial taxa are shared in the midgut of female D. abaensis, observable trends suggest variations in microbial diversity and composition as blood-feeding progresses. The present study provides a descriptive baseline of the midgut microbial composition of D. abaensis, which may inform future studies on tick biology and the ecology of tick-borne pathogens.

Animals↗