Jingmenviruses: Ubiquitous, understudied, segmented flavi-like viruses

Alongshan virus: An emerging arboviral challenge in regional health security

The Alongshan virus (ALSV), classified within the Flaviviridae family and belonging to the Jingmenvirus group, is a segmented RNA virus that was first identified in China in 2017. Since then, it has been reported in several Eurasian countries. Although no confirmed fatal cases have been documented, the potential public health risks associated with ALSV are significant and warrant serious attention. The emergence of ALSV has not only broadened the array of tick-borne diseases but has also enriched the research landscape surrounding segmented flaviviruses. Despite these advancements, our understanding of ALSV is still nascent, and its complex infection pathways remain largely unexplored. This review seeks to offer an in-depth examination of ALSV, addressing its biological properties, molecular features, epidemiological data, clinical presentations, and diagnostic methodologies. Our objective is to promote progress in the formulation of preventive, diagnostic, and therapeutic measures for this emerging segmented flavivirus.

Latitude-driven patterns and dynamics in Jingmen group viral lineages: Spatial correlation, recombination, and phylogeography

The global emergence of Jingmen group viruses (JMVs), including Jingmen tick virus (JMTV), Alongshan virus (ALSV), and Yanggou tick virus (YGTV), has significantly broadened our perspective on the potential public health risks posed by segmented flaviviruses. However, the global evolutionary and genetic epidemiology of JMVs remains unclear. In this study, we conducted a comprehensive analysis of the spatial correlation, recombination, and phylogeography of JMVs. Our phylogenetic analysis identified three latitudinal lineages: (1) a mid-high-latitude group with YGTV and ALSV, prevalent in Europe and Asia; (2) a mid-latitude group with JMTV in Romania, Turkey, Kosovo, Trinidad, and Tobago; and (3) a mid-low-latitude group with JMTV and the Sichuan tick virus in Brazil, Japan, China, Kenya, and Uganda. The strong correlation between genetic distance and latitude also supports a latitude-dependent evolutionary pattern. Notably, concordance between the phylogenies of dominant tick species and JMVs underscores the pivotal role of tick species in the evolution of JMVs. Furthermore, the detection of frequent intra-lineage recombination and global migration events underscores the ecological pressures and tick-mediated evolutionary mechanisms that propel the global dissemination of emerging segmented flaviviruses. Additionally, the complex interplay of JMV recombination and migration events of JMVs identified here, particularly the recombination between JMTV and ALSV from disparate regions and viral migration across different regions and continents, complicates their evolutionary interrelationships and heightens potential health risks. Overall, our study provides valuable insights into ecological factors and tick species-mediated evolution and transmission that shape the global spread of emerging segmented flaviviruses.

Simultaneous Detection and Genome Analysis of the Kindia Tick Virus in Cattle and Rhipicephalus Ticks in the Republic of Guinea

Background: Over the past decade, numerous new tick-associated flavi-like viruses with segmented genomes have been discovered almost worldwide. Kindia tick virus (KITV) was first detected in Rhipicephalus geigyi ticks in West Africa in 2017. The current study aimed to detect viral RNA in tick and cattle samples collected in Guinea and to perform complete sequencing of KITV isolates and their analysis. Methods: Adult ticks and blood samples were collected from cattle in Coyah, Dubréka, Forécariah, and Kindia prefectures of the Republic of Guinea in 2022. These samples were tested for KITV infection by RT-PCR with primers targeting the NS5 gene. Positive probes were sequenced using Illumina technology, and their analysis was performed for obtaining complete sequences of all KITV segments. Results: The RNA of the KITV was detected by RT-PCR in Rh. geigyi, Rh. annulatus ticks, and blood samples of cattle. The prevalence rates for cattle were 6.6%, for Rh. annulatus 6.9%, and for Rh. geigyi ticks 10.7%. The analysis of 15 complete sequences of KITV genomes showed 99.61-99.67% identity for amino acid sequences for segments 1 and 4 and 97.88-98.83% for segments 2 and 3 with previously detected KITV isolate in Guinea in 2017. Phylogenetic analysis demonstrated that obtained KITV sequences can be classified as typical for clade A of the Jingmen tick virus (JMTV) group together with Mogiana tick virus. Conclusion: The KITV isolates from cattle and feeding ticks show practically full identity sequences for all four viral segments, and these sequences can be classified as clade A of the segmented flavi-like virus JMTV group.

Molecular detection of novel Jingmen tick virus in hard ticks from diverse hosts in Guangxi, southwestern China

BACKGROUND

Ticks are the second most important vectors of arboviruses after mosquitoes, and they also serve as reservoir hosts for some zoonotic diseases. It is essential to understand the prevalence of tick-borne viruses in ticks from different sampling sites and vectors, as this information can facilitate the surveillance and prevention of arboviral infectious diseases.

METHODS

We systematically collected ticks from a variety of animals, including wildlife and domestic livestock, across 18 distinct regions in Guangxi Zhuang Autonomous Region(Guangxi). We then identified the ticks using traditional morphological classification and molecular biology methods to investigate the diversity of ticks in the regionWe also systematically examined the diversity of viruses carried by ticks using comprehensive virological methods based on viral metagenomics. We performed phylogenetic and recombination analyses for the assembled viral sequences.

RESULTS

We collected 1286 Ixodidae from 18 sampling sites in 17 districts of Guangxi. We identified 4 genera and 6 species of Ixodidae. We annotated 2 unclassified viruses and 13 known viral families. We assembled 208 nucleotide sequences and obtained six near full-length sequences of Jingmen tick virus (JMTV). Among these sequences, GXTV-PC4.2 and GXTV-43 were new mutant strains of JMTV. We detected genetic recombination of JMTV in segments 2, 3, and 4 of JMTV.

CONCLUSIONS

Our study uncovers a diverse tick fauna in Guangxi, including 4 genera and 6 species, and a broad virome with 13 viral families and 2 novel viruses. The JMTV, in particular, shows significant genetic diversity and potential for cross-species transmission, marked by new strains and recombination events. These findings underscore the need for vigilant tick-borne disease surveillance in Guangxi.

Discovery of additional genomic segments reveals the fluidity of jingmenvirus genomic organization

Jingmenviruses are a distinct group of flavi-like viruses characterized by a genome consisting of four to five segments. Here, we report the discovery of three novel putative jingmenviruses, identified by mining publicly available metagenomics data from mosquito and arachnid samples. Strikingly, these novel jingmenvirus sequences contain up to six genomic segments, with pairs of homologous segments coding for putative structural proteins. Following this discovery, we found an additional homologous segment for two other jingmenvirus genomes, which had gone unnoticed in the initial publications. The presence of a single version of the segments coding for non-structural proteins suggests that we have indeed identified jingmenviruses with infectious units that contain up to six segments. We compared these novel jingmenvirus sequences to published sequences, in particular the segments with multiple open reading frames (ORFs), and we propose that the putative translation initiation mechanisms involved for these segments are ribosomal frameshift resulting in the fusion of ORFs and leaky scanning for overlapping ORFs. These putative mechanisms, conserved for all jingmenvirus sequences analysed, including in homologous segments, require biological confirmation. We also generated structural models of two putative structural proteins in the duplicated segments, and the corresponding alignments enabled us to confirm or identify the homologous relationship between sequences that shared limited nucleotide or amino acid identity. Altogether, these results highlight the fluid nature of jingmenviruses, which is a hallmark of multipartite viruses. Different combinations of segments packaged in different virus particles could facilitate the acquisition or loss of genomic segments and a segment duplication following genomic drift. Our data therefore contribute to the evidence of the multipartite nature of jingmenviruses and the evolutionary role this organization may play.

Strange relatives: the enigmatic arbo-jingmenviruses and orthoflaviviruses

Arthropod - and vertebrate-associated jingmenviruses (arbo-JMV) have segmented positive-strand RNA genomes and are provisional members of the genus Orthoflavivirus (family Flaviviridae). Current investigations have described arbo-JMV infection in vertebrate hosts in proximity to humans. This raises concerns about the virus host range and public health implications. This review explores the genomic and evolutionary relationship between arbo-JMV and orthoflaviviruses and evaluates the potential of arbo-JMV to pose a public health threat.

Exploring the potential of tick transcriptomes for virus screening: A data reuse approach for tick-borne virus surveillance

BACKGROUND

We set out to investigate the utility of publicly available tick transcriptomic data to identify and characterize known and recently described tick-borne viruses, using de novo assembly and subsequent protein database alignment and taxonomical binning.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 127 virus contigs were recovered from 35 transcriptomes, originating from cell lines (40%), colony-reared ticks (25.7%) or field-collected ticks (34.2%). Generated virus contigs encompass DNA (n = 2) and RNA (n = 13) virus families, with 3 and 28 taxonomically distinct isolates, respectively. Known human and animal pathogens comprise 32.8% of the contigs, where Beiji nairovirus (BJNV) was the most prevalent tick-borne pathogenic virus, identified in 22.8% of the transcriptomes. Other pathogens included Nuomin virus (NUMV) (2.8%), African swine fever virus (ASFV) (5.7%), African horse sickness virus 3 (AHSV-3) (2.8%) and Alongshan virus (ALSV) (2.8%).

CONCLUSIONS

Previously generated transcriptome data can be leveraged for detecting tick-borne viruses, as exemplified by new descriptions of ALSV and BJNV in new geographic locations and other viruses previously detailed in screening reports. Monitoring pathogens using publicly available data might facilitate biosurveillance by directing efforts to regions of preliminary spillover and identifying targets for screening. Metadata availability is crucial for further assessments of detections.

Detection of multiple novel viruses in argasid and ixodid ticks in Mexico

We examined ticks from Mexico using viral metagenomics to increase our understanding of the composition and diversity of the tick virome. The analysis was performed using 3,127 ticks of four Ixodidae spp. and one Argasidae spp. collected in 2019 to 2021 from domestic animals in four states of Mexico (Chiapas, Chihuahua, Guerrero, and Michoacán). All ticks were homogenized and tested for viruses using two approaches. In the first approach, an aliquot of each homogenate underwent two blind passages in Ixodes scapularis (ISE6) cells. Supernatants from all second passage cultures were subjected to polyethylene glycol (PEG) precipitation to enrich for virions then RNAs were extracted from the precipitates and analyzed by unbiased high-throughput sequencing (UHTS). In the second approach, an aliquot of every homogenate was subjected to PEG precipitation then RNAs were extracted and analyzed by UHTS, allowing for the detection of viruses unable to replicate in ISE6 cells. We identified seven novel species of viruses from multiple taxonomic groups (Bunyavirales, Flaviviridae, Nodaviridae, Nyamivirdae, Rhabdoviridae, Solemoviridae, and Totiviridae), some of which are highly divergent from all classified viruses and cannot be assigned to any established genus. Twelve recognized species of viruses were also identified. In summary, multiple novel and recognized viruses were detected in ticks from Mexico, highlighting the remarkable diversity of the tick virome.

First detection and molecular characterization of Jingmen tick virus with a high occurrence in Rhipicephalus (Boophilus) microplus collected from livestock in Cameroon (2024)

BACKGROUND

Jingmen tick virus (JMTV) is a novel tick-borne virus detected for the first time in Rhipicephalus (Boophilus) microplus in China. To date, there is no information regarding the circulation of JMTV in ticks collected from livestock in Cameroon. As part of the surveillance for arboviral circulation, this study aimed to assess the presence of JMTV in ticks collected from livestock (cattle and sheep) in an area of the Akonolinga health district, Center Region, Cameroon.

METHODS

A cross sectional study was carried out during the dry season between 5 and 14 March 2024. Ticks were collected from cattle and sheep in six sampling sites in an area approximately 30 km long and 18 km wide along the Nyong River, in central Cameroon. Ticks were identified morphologically and molecularly. Total RNA/DNA was extracted from tick pools and screened for JMTV RNA using a segment 2 RT-qPCR system. Positive JMTV pools were sequenced for partial JMTV-Segment 1 and full genome analyses.

RESULTS

A total of 622 ticks, organized into 251 pools were collected from 155 cattle and nine sheep. They consisted of five species covering three genera: R. (B.) microplus (472; 75.9%), Amblyomma variegatum (118; 19.0%), Hyalomma truncatum (13; 2.1%), Hyalomma rufipes (2; 0.3%), and other Rhipicephalus spp. (17; 2.7%). The quantitative reverse transcription polymerase chain reaction (qRT-PCR) screening of 251 tick pools yielded 61 JMTV-positive pools, of which 58 corresponded to R. (B.) microplus. Multiple sequence analysis revealed that JMTV from the Akonolinga area shared > 95% identity with strains from Guinea, and that these strains clustered phylogenetically together.

CONCLUSIONS

We provide molecular evidence of the presence of JMTV in R. (B.) microplus and A. variegatum collected from cattle and sheep from an area not yet recognized as endemic for this virus, confirming its wide geographical distribution.

Integrated analysis of protein sequence and structure redefines viral diversity and the taxonomy of the Flaviviridae

The Flaviviridae are a family of non-segmented positive-sense enveloped RNA viruses containing significant pathogens including hepatitis C virus and yellow fever virus. Recent large-scale metagenomic surveys have identified many diverse RNA viruses related to classical orthoflaviviruses and pestiviruses but quite different genome lengths and configurations, and with a hugely expanded host range that spans multiple animal phyla, including molluscs, cnidarians and stramenopiles,, and plants. Grouping of RNA-directed RNA polymerase (RdRP) hallmark gene sequences of flavivirus and 'flavi-like' viruses into four divergent clades and multiple lineages within them was congruent with helicase gene phylogeny, PPHMM profile comparisons, and comparison of RdRP protein structure predicted by AlphFold2. These results support their classification into the established order, Amarillovirales, in three families (Flaviviridae, Pestiviridae, and Hepaciviridae), and 14 genera. This taxonomic framework informed by RdRP hallmark gene evolutionary relationships provides a stable reference from which major genome re-organisational events can be understood.

Identification and phylogenetic analysis of Jingmen tick virus in ticks and sheep from Henan Province, China

Jingmen tick virus (JMTV) is a novel segmented Flavivirus that was first identified from Rhipicephalus microplus in the Jingmen region of Hubei Province, China, in 2010. Subsequently, it was detected in a variety of countries and regions around the world. Meanwhile, JMTV has been proved to be pathogenic to humans and animals and could cause viremia in animals. However, the pathogenic mechanism of JMTV and what role animals play in the viral cycle have not yet been elucidated. In this study, 38 sheep sera were collected from Xinyang region of Henan Province, China and 204 ticks attached to the sheep were collected. The qRT-PCR and nested PCR were used to confirm the presence of JMTV in serum and tick samples. The results showed that the positive rate of JMTV in serum and ticks was 13.16% (5/38) and 7.84% (16/204), respectively. Phylogenetic analysis showed that JMTV sequences in sheep and ticks shared a high degree of identity with each other, and JMTV was relatively conserved in evolution. These results enriched the evidence for the prevalence of JMTV in animals and further deepened our understanding of the mechanisms and routes of JMTV transmission.

Epidemiology and global spread of emerging tick-borne Alongshan virus

The emergence and spread of novel viral pathogens is a major threat to human health, particularly in the context of climate and human-induced change in land use. Alongshan virus (ALSV) is a tick-borne virus associated with human disease, which was first identified in northeast China. More recently, several studies reported the emergence of ALSV in mammalian and arthropod hosts in multiple different countries outside of Asia, and the first viral genome sequencing data has become available. ALSV is a member of the Jingmenvirus group closely related to the Flaviviridae family. Unusually, the positive-sense, single-stranded RNA genome of ALSV is segmented and consists of four distinct segments, two of which show homology with the NS3 and NS5 protein encoding regions of non-segmented flaviviruses. Transmission of arthropod-borne pathogens will likely increase in the future due to environmental change mediated by a variety of environmental and ecological factors and increasing human encroachment into wild animal habitats. In this review, we present current knowledge of global ALSV distribution and emergence patterns, highlight genetic diversity, evolution and susceptible species. Finally, we discuss the role of this emerging tick-borne virus in the context of urbanization and global health.

Investigation of RNA Viruses in Culicoides Latreille, 1809 (Diptera: Ceratopogonidae) in a Mining Complex in the Southeastern Region of the Brazilian Amazon

The biting midges Culicoides Latreille, 1809 (Diptera: Ceratopogonidae) is highly relevant to epidemiology and public health, as it includes species that are potential vectors of human and animal arboviruses. The aim of this study was to investigate the presence of RNA viruses in species of the genus Culicoides collected in the Carajás mining complex in the state of Pará. The biting midges were collected in the municipalities of Canaã dos Carajás, Curionópolis and Marabá and morphologically identified. A total of 1139 specimens of seven Culicoides species were grouped into eight pools and subjected to metagenomic analysis. Eight new insect-specific viruses (ISVs) were characterized and assigned to the order Tolivirales, the families Chuviridae, Nodaviridae, Iflaviridae, Mesoniviridae, and Flaviviridae, and the taxon Negevirus. All viruses identified were assigned to clades, families and taxa never reported in Culicoides in Brazil. This study demonstrated that biting midges harbor a significant diversity of RNA viruses, many of which are still unknown, highlighting the importance of studies aiming at virome of these insects.

Metagenomic Nanopore Sequencing of Tickborne Pathogens, Mongolia

We performed nanopore-based metagenomic screening on 885 ticks collected from 6 locations in Mongolia and divided the results into 68 samples: 23 individual samples and 45 pools of 2-12 tick samples each. We detected bacterial and parasitic pathogens Anaplasma ovis, Babesia microti, Coxiella burnetii, Borrelia miyamotoi, Francisella tularensis subsp. holarctica and novicida, Spiroplasma ixodetis, Theileria equi, and Rickettsia spp., including R. raoultii, R. slovaca, and R. canadensis. We identified the viral pathogens Crimean-Congo hemorrhagic fever virus (2.9%), recently described Alongshan virus (ALSV) (2.9%), and Beiji nairovirus (5.8%). We assembled ALSV genomes, and maximum-likelihood analyses revealed clustering with viruses reported in humans and ticks from China. For ALSV, we identified surface glycoprotein markers associated with isolates from Asia viruses hosted by Ixodes persulcatus ticks. We also detected 20 virus species of unknown public health impact, including a near-complete Yanggou tick virus genome. Our findings demonstrate that nanopore sequencing can aid in detecting endemic and emerging tickborne pathogens.

Diverse RNA viruses of parasitic nematodes can elicit antibody responses in vertebrate hosts

Parasitic nematodes have an intimate, chronic and lifelong exposure to vertebrate tissues. Here we mined 41 published parasitic nematode transcriptomes from vertebrate hosts and identified 91 RNA viruses across 13 virus orders from 24 families in ~70% (28 out of 41) of parasitic nematode species, which include only 5 previously reported viruses. We observe widespread distribution of virus-nematode associations across multiple continents, suggesting an ancestral acquisition event and host-virus co-evolution. Characterization of viruses of Brugia malayi (BMRV1) and Onchocerca volvulus (OVRV1) shows that these viruses are abundant in reproductive tissues of adult parasites. Importantly, the presence of BMRV1 RNA in B. malayi parasites mounts an RNA interference response against BMRV1 suggesting active viral replication. Finally, BMRV1 and OVRV1 were found to elicit antibody responses in serum samples from infected jirds and infected or exposed humans, indicating direct exposure to the immune system.

First detection of Jingmen tick virus in Corsica with a new generic RTqPCR system

Jingmen tick virus (JMTV) is a recently discovered segmented RNA virus, closely related to flaviviruses. It was identified for the first time in 2014, in China and subsequently in Brazil. Following this discovery, JMTV-related sequences have been identified in arthropods, vertebrates (including humans), plants, fungus, and environmental samples from Asia, America, Africa, Europe, and Oceania. Several studies suggest an association between these segmented flavi-like viruses, termed jingmenviruses, and febrile illness in humans. The development of rapid diagnostic assays for these viruses is therefore crucial to be prepared for a potential epidemic, for the early detection of these viruses via vector surveillance or hospital diagnosis. In this study, we designed a RT-qPCR assay to detect tick-associated jingmenviruses, validated it and tested its range and limit of detection with six tick-associated jingmenviruses using in vitro transcripts. Then, we screened ticks collected in Corsica (France) from different livestock species, in order to determine the distribution of these viruses on the island. In total, 6269 ticks from eight species were collected from 763 cattle, 538 horses, 106 sheep, and 218 wild boars and grouped in 1715 pools. We report the first detection of JMTV in Corsica, in Rhipicephalus bursa, Hyalomma marginatum and R. sanguineus ticks collected from cattle and sheep. The highest prevalence was found in the Rhipicephalus genus. The complete genome of a Corsican JMTV was obtained from a pool of Rhipicephalus bursa ticks and shares between 94.7% and 95.1% nucleotide identity with a JMTV sequence corresponding to a human patient in Kosovo and groups phylogenetically with European JMTV strains. These results show that a Mediterranean island such as Corsica could act as a sentinel zone for future epidemics.

[Prevalence and genetic diversity of the Alongshan virus (Flaviviridae) circulating in ticks in the south of Eastern Siberia]

INTRODUCTION

Tick-borne infections are of great importance for many regions of Russia, including Eastern Siberia. This unfavorable epidemiological situation can be characterized not only by the circulation of well-known tick-borne infections, but also by the identification of new pathogens, the role of which remains little or generally unexplored. Multicomponent flavi-like viruses can cause infectious diseases in humans and pose a threat to public health. The purpose of the study was the identification and molecular genetic characterization of the Alongshanvirus (Flaviviridae, ALSV) isolates, transmitted by ticks in the south of Eastern Siberia.

MATERIALS AND METHODS

Total 1060 ticks were collected and analyzed from the territory of the Republics of Khakassia, Tuva, Buryatia, Irkutsk Region and Transbaikal Territory (Zabaykalsky Krai) in the spring-summer period 2023. ALSV RNA was detected by RT-PCR followed by nucleotide sequence determination and phylogenetic analysis for each segment of the genome.

RESULTS

The ALSV infection rate in Ixodespersulcatus ticks collected in the Republic of Khakassia was 3.3% (95% CI: 1.4-7.5); in Irkutsk Oblast - 1.0% (95% CI: 0.3-3.7); in the Republic of Tuva - 0.9% (95% CI: 0.3-3.4) and in Transbaikal Krai - 0.7% (95% CI: 0.2-3.6). Sequences of all four segments of ALSV genetic variants circulating in I. persulcatus ticks in the south of Eastern Siberia are grouped with sequences found in China and clustered into the Asian subgroup transmitted by taiga ticks. The level of difference in the nucleotide sequences of genome fragments among the identified genetic variants of ALSV ranged from 2 to 3%.

CONCLUSION

The article shows the widespread distribution of ALSV in I. persulcatus ticks in the Republics of Khakassia and Tyva, Irkutsk Oblast and Transbaikal Territory. The obtained data actualize monitoring of changes in the area of distribution of potentially dangerous for humans flavi-like viruses and their vectors.

Identification and phylogenetic analysis of Jingmen tick virus in Jiangxi Province, China

Jingmen tick virus (JMTV) is a newly identified segmented flavivirus that has been recognized in multiple hosts, such as humans, buffalos, bats, rodents, mosquitos and ticks. Various clinical cases and studies manifested that JMTV is a true arbovirus with wide host spectrum and showed potential threats toward public health. JMTV has been reported in multiple countries in Asia, Europe, Africa, and America. Moreover, wild boars serve as an important intermediary between humans and the wild ecological system. In China, it has been reported in nine provinces, while the prevalence and the distribution of JMTV in most regions including Jiangxi Province are still unknown. Thus, to profile the distribution of JMTV in Jiangxi Province, an epidemiological investigation was carried out from 2020 to 2022. In current study, 66 ticks were collected from 17 wild boars in Jiangxi Province. The results showed that 12 out of 66 ticks were JMTV positive, indicating JMTV is prevalent in ticks and boars in Jiangxi Province. The genome sequences of JMTV strain WY01 were sequenced to profile viral evolution of JMTV in China. Phylogenetic analysis divided JMTV strains into two genotypes, Group I and Group II. WY01 belongs to Group II and it shares the closest evolutionary relationship with the Japan strains rather than the strains from neighboring provinces in China suggesting that JMTV might have complex transmission routes. Overall, current study, for the first time, reported that JMTV is prevalent in Jiangxi Province and provided additional information concerning JMTV distribution and evolution in China.

Viromes of Haemaphysalis longicornis reveal different viral abundance and diversity in free and engorged ticks

Haemaphysalis longicornis ticks, commonly found in East Asia, can transmit various pathogenic viruses, including the severe fever with thrombocytopenia syndrome virus (SFTSV) that has caused febrile diseases among humans in Hubei Province. However, understanding of the viromes of H. longicornis was limited, and the prevalence of viruses among H. longicornis ticks in Hubei was not well clarified. This study investigates the viromes of both engorged (fed) and free (unfed) H. longicornis ticks across three mountainous regions in Hubei Province from 2019 to 2020. RNA-sequencing analysis identified viral sequences that were related to 39 reference viruses belonging to unclassified viruses and seven RNA viral families, namely Chuviridae, Nairoviridae, Orthomyxoviridae, Parvoviridae, Phenuiviridae, Rhabdoviridae, and Totiviridae. Viral abundance and diversity in these ticks were analysed, and phylogenetic characteristics of the Henan tick virus (HNTV), Dabieshan tick virus (DBSTV), Okutama tick virus (OKTV), and Jingmen tick virus (JMTV) were elucidated based on their full genomic sequences. Prevalence analysis demonstrated that DBSTV was the most common virus found in individual H. longicornis ticks (12.59%), followed by HNTV (0.35%), whereas JMTV and OKTV were not detected. These results improve our understanding of H. longicornis tick viromes in central China and highlight the role of tick feeding status and geography in shaping the viral community. The findings of new viral strains and their potential impact on public health raise the need to strengthen surveillance efforts for comprehensively assessing their spillover potentials.

Tick-borne viruses and their risk to public health in the Caribbean: Spotlight on bats as reservoirs in Cuba

In recent decades, tick-borne diseases (TBDs) have surged and expanded globally due to factors like changes in human activities, land use patterns, and climate change, and it have been associated with the emergence of zoonotic diseases. Cuba faces the impact of ticks on human health and the economy. Although Cuba has studied TBDs extensively for the past 50 years, focus on tick-borne viral pathogens affecting humans remains scant. Despite TBDs not currently being a major health concern in Cuba, factors like inadequate clinician awareness, climate conditions, global tick emergence, and evidence of zoonotic pathogens in ticks underscore the importance of enhanced TBD surveillance in the country. Here we revised the available information on ticks as vectors of pathogenic viruses to humans, spotlighting bats as potential reservoirs of tick-borne viruses (TBVs). Ticks on bats have gained interest as potential reservoirs of pathogenic viruses to humans in Cuba and worldwide. Understanding their role in maintaining viruses and their potential transmission to humans is crucial for the implementation of surveillance and control programs to reduce the risk of tick-borne viral diseases and public health management.

Metatranscriptomics Reveals the RNA Virome of Ixodes Persulcatus in the China-North Korea Border, 2017

In recent years, numerous viruses have been identified from ticks, and some have been linked to clinical cases of emerging tick-borne diseases. Chinese northeast frontier is tick infested. However, there is a notable lack of systematic monitoring efforts to assess the viral composition in the area, leaving the ecological landscape of viruses carried by ticks not clear enough. Between April and June 2017, 7101 ticks were collected to perform virus surveillance on the China-North Korea border, specifically in Tonghua, Baishan, and Yanbian. A total of 2127 Ixodes persulcatus were identified. Further investigation revealed the diversity of tick-borne viruses by transcriptome sequencing of Ixodes persulcatus. All ticks tested negative for tick-borne encephalitis virus. Transcriptome sequencing expanded 121 genomic sequence data of 12 different virus species from Ixodes persulcatus. Notably, a new segmented flavivirus, named Baishan Forest Tick Virus, were identified, closely related to Alongshan virus and Harz mountain virus. Therefore, this new virus may pose a potential threat to humans. Furthermore, the study revealed the existence of seven emerging tick-borne viruses dating back to 2017. These previously identified viruses included Mudanjiang phlebovirus, Onega tick phlebovirus, Sara tick phlebovirus, Yichun mivirus, and three unnamed viruses (one belonging to the Peribunyaviridae family and the other two belonging to the Phenuiviridae family). The existence of these emerging tick-borne viruses in tick samples collected in 2017 suggests that their history may extend further than previously recognized. This study provides invaluable insights into the virome of Ixodes persulcatus in the China-North Korea border region, enhancing our ongoing efforts to manage the risks associated with tick-borne viruses.

Meta-transcriptomics for the diversity of tick-borne virus in Nujiang, Yunnan Province

Ticks, an arthropod known for transmitting various pathogens such as viruses, bacteria, and fungi, pose a perpetual public health concern. A total of 2,570 ticks collected from Nujiang Prefecture in Yunnan Province between 2017 and 2022 were included in the study. Through the meta-transcriptomic sequencing of four locally distributed tick species, we identified 13 RNA viruses belonging to eight viral families, namely, Phenuiviridae, Nairoviridae, Peribunyaviridae, Flaviviridae, Chuviridae, Rhabdoviridae, Orthomyxoviridae, and Totiviridae. The most prevalent viruses were members of the order Bunyavirales, including three of Phenuiviridae, two were classified as Peribunyaviridae, and one was associated with Nairoviridae. However, whether they pose a threat to human health still remains unclear. Indeed, this study revealed the genetic diversity of tick species and tick-borne viruses in Nujiang Prefecture based on COI gene and tick-borne virus research. These data clarified the genetic evolution of some RNA viruses and furthered our understanding of the distribution pattern of tick-borne pathogens, highlighting the importance and necessity of monitoring tick-borne pathogens.

Diversity of Viruses in Ixodes ricinus in Europe including Novel and Potential Arboviruses

Tick-borne pathogens are responsible for many vector-borne diseases in Europe, causing important problems for human and animal health. The composition of viral communities in ticks and their interactions with pathogens is little understood, especially in Eastern Europe, an area that represents a major hub for animal-arthropod vectors exchanges. In this study, we used metatranscriptomics to characterize the virome of 2,753 Ixodes ricinus ticks collected from France and Romania, focusing on viruses that could potentially have implications for human or animal health. Among the great viral diversity of viruses identified, we reported a novel strain of Tribec virus, an important human pathogen that was found in Romanian ticks. We detected viruses belonging to the Phenuiviridae and Nairoviridae families close to human and animal pathogens, suggesting that these viruses could constitute novel arboviruses. We used luciferase immunoprecipitation system targeting external viral proteins of viruses identified among the Sedoreoviridae, Phenuiviridae, and Nairoviridae families to screen serum samples from small ruminants' exposed to tick bites. The results suggest that part (approximately 12%, 95% CI 9.1-16.2) of the small ruminant population from Danube Delta, was exposed to viruses related to bi- or tri-segmented nairoviruses, but cross-reactive viruses could not be confirmed with certainly. The strategy developed in this study serves as a key step in predicting potential new disease outbreaks and can be readily adapted to study other reservoirs, vectors, and interfaces involving susceptible hosts.

The expanding range of emerging tick-borne viruses in Eastern Europe and the Black Sea Region

We analysed both pooled and individual tick samples collected from four countries in Eastern Europe and the Black Sea region, using metagenome-based nanopore sequencing (NS) and targeted amplification. Initially, 1337 ticks, belonging to 11 species, were screened in 217 pools. Viruses (21 taxa) and human pathogens were detected in 46.5% and 7.3%, respectively. Tick-borne viral pathogens comprised Tacheng Tick Virus 2 (TTV2, 5.9%), Jingmen Tick Virus (JMTV, 0.9%) and Tacheng Tick Virus 1 (TTV1, 0.4%). An association of tick species with individual virus taxa was observed, with the exception of TTV2, which was observed in both Dermacentor and Haemaphysalis species. Individual ticks from pools with pathogen detection were then further screened by targeted amplification and then NS, which provided extensive genome data and revealed probable pathogen Haseki Tick Virus (HTV, 10.2%). Two distinct TTV2 clades were observed in phylogenetic analysis, one of which included closely related Dermacentor reticulatus Uukuviruses. JMTV detection indicated integrated virus sequences. Overall, we observed an expansion of newly documented pathogenic tick-borne viruses into Europe, with TTV1 being identified on the continent for the first time. These viruses should be included in the diagnostic assessment of symptomatic cases associated with tick bites and vector surveillance efforts. NS is shown as a useful tool for monitoring tick-associated pathogens in pooled or individual samples.

Genomics evolution of Jingmen viruses associated with ticks and vertebrates

Jingmen virus (JMV) associated with ticks and vertebrates have been found to be related to human disease. We obtained the genome of a Jingmen tick virus (JMTV) strain from Rhipicephalus microplus in Guizhou province and compared the genomes of seven JMV species associated with ticks and vertebrates to understand the evolutionary relationships. The topology of the phylogenetic tree of segment 1 and segment 3 is similar, and segment 2 and segment 4 formed two different topologies, with the main differences being between Alongshan virus (ALSV), Takachi virus, Yanggou tick virus and Pteropus lylei jingmen virus (PLJV), and the possibility of genetic reassortment among these viruses. Moreover, we detected recombination within JMTV and between PLJV and ALSV. The genetic reassortment and recombination that occurs during cross-species transmission of these JMV associated with ticks and vertebrates not only complicates their evolutionary relationships, but also raises the risk of these viruses to humans.

Jingmen tick virus: an emerging arbovirus with a global threat

Jingmen tick virus (JMTV), belonging to the Flaviviridae family, is a novel segmented RNA virus identified in 2014 in the Jingmen region of Hubei Province, China. Up to now, JMTV has been detected in a variety of countries or regions in Asia, Europe, Africa, and the Americas, involving a wide range of arthropods and mammals, and even humans. The JMTV genome is composed of four linear RNA segments, two of which are derived from flaviviruses, while the other two segments are unique to JMTV and has no matching virus. Currently, JMTV has been shown to have a pathogenic effect on humans. Humans who had been infected would develop viremia and variable degrees of clinical symptoms. However, the pathogenic mechanism of JMTV has not been elucidated yet. Therefore, it is crucial to strengthen the epidemiological surveillance and laboratory studies of JMTV.

Quantitative Polymerase Chain Reaction System for Alongshan Virus Detection

The recently discovered Jingmenvirus group includes viruses with a segmented genome, RNA of a positive polarity, and several proteins with distant homology to the proteins of the members of the genus Orthoflavivirus. Some Jingmenvirus group members, namely the Alongshan virus (ALSV) and Jingmen tick virus, are reported to be tick-borne human pathogens that can cause a wide variety of symptoms. The ALSV is widely distributed in Eurasia, yet no reliable assay that can detect it exists. We describe a qPCR system for ALSV detection. Our data showed that this system can detect as little as 104 copies of the ALSV in a sample. The system showed no amplification of the common tick-borne viruses circulating in Eurasia, i.e., the Yanggou tick virus-which is another Jingmenvirus group member-or some known members of the genus Orthoflavivirus. The qPCR system was tested and had no nonspecific signal for the Ixodes ricinus, I. persulcatus, Dermacentor reticulatus, D. marginatus, Haemaphysalis concinna, and H. japonica ticks. The qPCR system had no nonspecific signal for human and sheep serum as well. Overall, the qPCR system described here can be used for reliable and quantitative ALSV detection.

Longitudinal Study of Viral Diversity Associated with Mosquito Species Circulating in Cambodia

Arthropod-borne viruses (arboviruses) pose a significant global health threat and are primarily transmitted by mosquitoes. In Cambodia, there are currently 290 recorded mosquito species, with at least 17 of them considered potential vectors of arboviruses to humans. Effective surveillance of virome profiles in mosquitoes from Cambodia is vital, as it could help prevent and control arbovirus diseases in a country where epidemics occur frequently. The objective of this study was to identify and characterize the viral diversity in mosquitoes collected during a one-year longitudinal study conducted in various habitats across Cambodia. For this purpose, we used a metatranscriptomics approach and detected the presence of chikungunya virus in the collected mosquitoes. Additionally, we identified viruses categorized into 26 taxa, including those known to harbor arboviruses such as Flaviviridae and Orthomyxoviridae, along with a group of viruses not yet taxonomically identified and provisionally named "unclassified viruses". Interestingly, the taxa detected varied in abundance and composition depending on the mosquito genus, with no significant influence of the collection season. Furthermore, most of the identified viruses were either closely related to viruses found exclusively in insects or represented new viruses belonging to the Rhabdoviridae and Birnaviridae families. The transmission capabilities of these novel viruses to vertebrates remain unknown.

Identification of novel Jingmen tick virus from parasitic ticks fed on a giant panda and goats in Sichuan Province, southwestern China

Introduction

Tick-borne viruses (TBVs) pose a significant risk to the health of humans and other vertebrates. A class of multisegmented flavi-like viruses, Jingmen tick virus (JMTV) was first discovered in Rhipicephalus microplus ticks collected from Jingmen of Hubei Province, China in 2010. JMTV has been confirmed to have a relatively wide distribution in vectors and hosts and is associated with human diseases.

Methods

Parasitic and host-seeking ticks were collected in Wolong Nature Reserve, Sichuan Province. Total RNA was extracted and then enriched the viral RNA. The DNA library was constructed and then were sequenced with MGI High-throughput Sequencing Set (PE150). After the adaptor sequences,low-quality bases and host genome were removed, resulting reads classified as a virus were subsequently de novo assembled into contigs, which were then compared to the NT database. Those annotated under the kingdom virus were initially identified as potential virus-associated sequences. Phylogenetic and Reassortment analysis of sequences were performed using MEGA and SimPlot software, respectively.

Results and discussion

Two host-seeking ticks and 17 ticks that fed on giant pandas and goats were collected. Through high-throughput sequencing, whole virus genomes were attained from four tick samples (PC-13, PC-16, PC-18, and PC-19) that shared 88.7-96.3% similarity with known JMTV. Phylogenetic tree showed that it was a novel JMTV-like virus, referred to as Sichuan tick virus, which also had the signals of reassortment with other JMTV strains, suggesting a cross-species transmission and co-infection of segmented flavi-like viruses among multiple tick hosts.

Conclusion

We discovered and confirmed one new Jingmen tick virus, Sichuan tick virus. Further investigation is required to determine the pathogenicity of Sichuan tick virus to humans and animals, as well as its epidemiological characteristics in nature.

Impact of nanopore-based metagenome sequencing on tick-borne virus detection

Introduction

We evaluated metagenomic nanopore sequencing (NS) in field-collected ticks and compared findings from amplification-based assays.

Methods

Forty tick pools collected in Anatolia, Turkey and screened by broad-range or nested polymerase chain reaction (PCR) for Crimean-Congo Hemorrhagic Fever Virus (CCHFV) and Jingmen tick virus (JMTV) were subjected to NS using a standard, cDNA-based metagenome approach.

Results

Eleven viruses from seven genera/species were identified. Miviruses Bole tick virus 3 and Xinjiang mivirus 1 were detected in 82.5 and 2.5% of the pools, respectively. Tick phleboviruses were present in 60% of the pools, with four distinct viral variants. JMTV was identified in 60% of the pools, where only 22.5% were PCR-positive. CCHFV sequences characterized as Aigai virus were detected in 50%, where only 15% were detected by PCR. NS produced a statistically significant increase in detection of these viruses. No correlation of total virus, specific virus, or targeted segment read counts was observed between PCR-positive and PCR-negative samples. NS further enabled the initial description of Quaranjavirus sequences in ticks, where human and avian pathogenicity of particular isolates had been previously documented.

Discussion

NS was observed to surpass broad-range and nested amplification in detection and to generate sufficient genome-wide data for investigating virus diversity. It can be employed for monitoring pathogens in tick vectors or human/animal clinical samples in hot-spot regions for examining zoonotic spillover.