Detection and molecular characterization of Mogiana tick virus (MGTV) in Rhipicephalus microplus collected from cattle in a savannah area, Uberlândia, Brazil

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.

Distribution prediction of the habitat of Jingmen tick virus in China

Jingmen tick virus (JMTV) is widely distributed in China, and human cases have been reported. Therefore, the objectives of this study were to understand the distribution of the JMTV in suitable areas in China under the current and projected future climates. We used two pairs of JMTV primers to detect ticks in Guizhou Province via PCR and obtained data on JMTV detection in other regions through literature research. We obtained climate data from China. Finally, maximum entropy, a boosted regression tree model, and a random forest model were used for prediction. The predictive performance of the model was evaluated by the area under the curve (AUC) of the receiver operating characteristic (ROC) curve. The JMTV positivity rate in Guizhou Province was 11.02%, which was lower than the overall national positivity rate of 16.9%. The predicted probability increased monotonically with increasing monthly mean temperature. China's high JMTV habitat is concentrated in the Daxinganling region of Heilongjiang, Shanghai, and Hainan Provinces, with the total area of high JMTV habitat accounting for 1.94% of the country's total land area. In the future, from 2021 to 2040, the area of JMTV habitat area in China will show an expanding trend. Our maps of JMTV distributions provide effective early warning information for monitoring JMTV and rapidly detecting outbreaks. The potential distribution of JMTV in China is expected to increase in size in the future, requiring continuous attention and surveillance.IMPORTANCESince the first detection of the Jingmen tick virus (JMTV) in ticks in 2014, it has been detected on several continents around the world. JMTV has also been detected in several regions of China, and human cases have been reported. JMTV has many types of hosts, including ticks, mice, bats, and turtles. It can be spread with these hosts in close proximity or over long distances. As a segmented virus, JMTV is capable not only of genetic mutation and recombination but also of genetic reassortment, resulting in changes in viral infectivity or pathogenicity. However, many uninvestigated areas still exist in China. Therefore, we investigated ticks carrying JMTV in Guizhou Province. We also predicted the distribution of JMTV in China by combining previous data.

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.

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.

The infection kinetics and transmission potential of two Guaico Culex viruses in Culex quinquefasciatus mosquitoes

Guaico Culex virus (GCXV) is a newly identified segmented Jingmenvirus from Culex spp. mosquitoes in Central and South America. The genome of GCXV is composed of four or five single-stranded positive RNA segments. However, the infection kinetics and transmission capability of GCXV in mosquitoes remain unknown. In this study, we used reverse genetics to rescue two GCXVs (4S and 5S) that contained four and five RNA segments, respectively, in C6/36 ​cells. Further in vitro characterization revealed that the two GCXVs exhibited comparable replication kinetics, protein expression and viral titers. Importantly, GCXV RNAs were detected in the bodies, salivary glands, midguts and ovaries of Culex quinquefasciatus at 4-10 days after oral infection. In addition, two GCXVs can colonize Cx. quinquefasciatus eggs, resulting in positive rates of 15%-35% for the second gonotrophic cycle. In conclusion, our results demonstrated that GCXVs with four or five RNA segments can be detected in Cx. quinquefasciatus eggs during the first and second gonotrophic cycles after oral infection.

Genomic and phylogenetic profiling of RNA of tick-borne arboviruses in Hainan Island, China

Ticks act as vectors and hosts of numerous arboviruses. Examples of medically important arboviruses include the tick-borne encephalitis virus, Crimean Congo hemorrhagic fever, and severe fever with thrombocytopenia syndrome. Recently, some novel arboviruses have been identified in blood specimens of patients with unexplained fever and a history of tick bites in Inner Mongolia. Consequently, tick-borne viruses are a major focus of infectious disease research. However, the spectrum of tick-borne viruses in subtropical areas of China has yet to be sufficiently characterized. In this study, we collected 855 ticks from canine and bovine hosts in four locations in Hainan Province. The ticks were combined into 18 pools according to genus and location. Viral RNA-sequence libraries were subjected to transcriptome sequencing analysis. Molecular clues from metagenomic analyses were used to classify sequence reads into virus species, genera, or families. The diverse viral reads closely associated with mammals were assigned to 12 viral families and important tick-borne viruses, such as Jingmen, Beiji nairovirus, and Colorado tick fever. Our virome and phylogenetic analyses of the arbovirus strains provide basic data for preventing and controlling human infectious diseases caused by tick-borne viruses in the subtropical areas of China.

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.

Perception of Ticks and Tick-Borne Diseases Worldwide

In this comprehensive review study, we addressed the challenge posed by ticks and tick-borne diseases (TBDs) with growing incidence affecting human and animal health worldwide. Data and perspectives were collected from different countries and regions worldwide, including America, Europe, Africa, Asia, and Oceania. The results updated the current situation with ticks and TBD and how it is perceived by society with information bias and gaps. The study reinforces the importance of multidisciplinary and international collaborations to advance in the surveillance, communication and proposed future directions to address these challenges.

Detection and Characterization of Alongshan Virus in Ticks and Tick Saliva from Lower Saxony, Germany with Serological Evidence for Viral Transmission to Game and Domestic Animals

The newly discovered group of Jingmenviruses has been shown to infect a wide range of hosts and has been associated with febrile illness in humans. During a survey for Jingmenviruses in ticks from Lower Saxony, Germany, Alongshan virus (ALSV) was identified in Ixodes spp. ticks. Additional virus screenings revealed the presence of ALSV in the bodies and saliva of ticks collected at several locations in Lower Saxony. Vector competence studies that included Ixodes ricinus and Dermacentor reticulatus validated the replication of ALSV within those tick species. In vitro feeding experiments with ALSV-injected Ixodes ricinus demonstrated effective viral transmission during blood feeding. To evaluate the potential viral transmission during a natural blood meal, sera from wild game and domestic animals were investigated. One serum sample from a red deer was found to be positive for ALSV RNA, while serological screenings in game and domestic animals revealed the presence of ALSV-specific antibodies at different locations in Lower Saxony. Overall, those results demonstrate the broad distribution of ALSV in ticks in Lower Saxony and hypothesize frequent exposure to animals based on serological investigations. Hence, its potential risk to human and animal health requires further investigation.

Skin infectome of patients with a tick bite history

Introduction

Ticks are the most important obligate blood-feeding vectors of human pathogens. With the advance of high-throughput sequencing, more and more bacterial community and virome in tick has been reported, which seems to pose a great threat to people.

Methods

A total of 14 skin specimens collected from tick-bite patients with mild to severe symptoms were analyzed through meta-transcriptomic sequencings.

Results

Four bacteria genera were both detected in the skins and ticks, including Pseudomonas, Acinetobacter, Corynebacterium and Propionibacterium, and three tick-associated viruses, Jingmen tick virus (JMTV), Bole tick virus 4 (BLTV4) and Deer tick mononegavirales-like virus (DTMV) were identified in the skin samples. Except of known pathogens such as pathogenic rickettsia, Coxiella burnetii and JMTV, we suggest Roseomonas cervicalis and BLTV4 as potential new agents amplified in the skins and then disseminated into the blood. As early as 1 day after a tick-bite, these pathogens can transmit to skins and at most four ones can co-infect in skins.

Discussion

Advances in sequencing technologies have revealed that the diversity of tick microbiome and virome goes far beyond our previous understanding. This report not only identifies three new potential pathogens in humans but also shows that the skin barrier is vital in preventing horizontal transmissions of tick-associated bacteria or virus communities to the host. It is the first research on patients' skin infectome after a tick bite and demonstrates that more attention should be paid to the cutaneous response to prevent tick-borne illness.

Jingmenviruses: Ubiquitous, understudied, segmented flavi-like viruses

Jingmenviruses are a group of viruses identified recently, in 2014, and currently classified by the International Committee on Taxonomy of Viruses as unclassified Flaviviridae. These viruses closely related to flaviviruses are unique due to the segmented nature of their genome. The prototype jingmenvirus, Jingmen tick virus (JMTV), was discovered in Rhipicephalus microplus ticks collected from China in 2010. Jingmenviruses genomes are composed of four to five segments, encoding for up to seven structural proteins and two non-structural proteins, both of which display strong similarities with flaviviral non-structural proteins (NS2B/NS3 and NS5). Jingmenviruses are currently separated into two phylogenetic clades. One clade includes tick- and vertebrate-associated jingmenviruses, which have been detected in ticks and mosquitoes, as well as in humans, cattle, monkeys, bats, rodents, sheep, and tortoises. In addition to these molecular and serological detections, over a hundred human patients tested positive for jingmenviruses after developing febrile illness and flu-like symptoms in China and Serbia. The second phylogenetic clade includes insect-associated jingmenvirus sequences, which have been detected in a wide range of insect species, as well as in crustaceans, plants, and fungi. In addition to being found in various types of hosts, jingmenviruses are endemic, as they have been detected in a wide range of environments, all over the world. Taken together, all of these elements show that jingmenviruses correspond exactly to the definition of emerging viruses at risk of causing a pandemic, since they are already endemic, have a close association with arthropods, are found in animals in close contact with humans, and have caused sporadic cases of febrile illness in multiple patients. Despite these arguments, the vast majority of published data is from metagenomics studies and many aspects of jingmenvirus replication remain to be elucidated, such as their tropism, cycle of transmission, structure, and mechanisms of replication and restriction or epidemiology. It is therefore crucial to prioritize jingmenvirus research in the years to come, to be prepared for their emergence as human or veterinary pathogens.

Identification of Jingmen tick virus (JMTV) in Amblyomma testudinarium from Fujian Province, southeastern China

Background

Jingmen tick virus (JMTV) is a newly discovered tick-borne virus that can cause disease in humans. This virus has been authenticated as being extremely widespread worldwide and as posing a significant threat to public health and safety.

Methods

We collected 35 ticks belonging to two tick species from wild boars in Nanping, Fujian Province, China. JMTV-specific genes were amplified by qRT-PCR and nested PCR to confirm the presence of this pathogen.

Results

More than one third of of all ticks collected (11/35) were positive for JMTV. Viral sequences were obtained from three of the JMTV-positive ticks, including the complete genomic sequence from one tick. This was the first time that JMTV was identified in the hard-bodied tick Amblyomma testudinarium. Phylogenetic analysis revealed that JMTV from Fujian Province shared > 90% identity with other isolates derived from China, but was distinct from those reported in France and Cambodia.

Conclusions

JMTV is characterized by relatively low mutations and has its own local adaptive characteristics in different regions. Our findings provide molecular evidence of the presence of JMTV in an overlooked tick species from an area not unrecognized as being endemic. They also suggest that JMTV occupies a wider geographical distribution than currently believed and is a potential disease vector.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05478-2.

Diversity of tick species (Acari: Ixodidae) in military training areas in Southeastern Brazil

Tick-borne pathogens belong to one of the two main groups of occupational biohazards, and occupational exposure to such agents puts soldiers at risk of zoonotic infections, such as those caused by rickettsiae. There are few studies on acarological fauna and occupational risk in military areas in Brazil. Thus, the present study aimed to analyze the diversity of ticks present in the military training areas of municipalities in the Southeast Region of Brazil. The ticks were collected from the selected areas using the dragging and flagging techniques as well as by visual detection on the operators' clothing, and environmental information was also recorded. A total of ten species were collected from the 66 surveyed areas, belonging to five genera and nine species: Amblyomma sculptum, Amblyomma dubitatum, Amblyomma brasiliense, Amblyomma longirostre, Amblyomma aureolatum, Dermacentor nitens, Rhipicephalus spp., Ixodes spp. and Haemaphysalis spp. The frequent presence of tick species in military training areas along with traces and sightings of wild animals, most commonly capybaras (Hydrochoerus hydrochaeris), in most of the studied areas, indicates high levels of exposure of the military to tick vectors of spotted fever group rickettsiae and the possible occurrence of infections among the troops.

Several Tick-Borne Pathogenic Viruses in Circulation in Anatolia, Turkey

Introduction: We screened host-collected ticks for tick-borne viruses, including those recently documented as human pathogens. Methods: During 2020-2021, ticks removed form cattle, sheep, dogs, and cats in 11 provinces in 5 geographically distinct regions of Anatolia were identified, pooled, and screened using pan-nairovirus, pan-flavivirus and individual assays for Jingmen tick virus (JMTV), and Tacheng tick virus 1 and 2 (TcTV-1 and TcTV-2). Results: A total of 901 tick specimens, comprising 6 species were included. Rhipicephalus sanguineus complex was the most abundant species (44.1%), followed by Rhipicephalus bursa (38.3%), Haemaphysalis parva (7.2%), and others. The specimens were screened in 158 pools with 12 pools (7.6%) being positive. Crimean-Congo hemorrhagic fever virus (CCHFV) lineage Europe 2 (genotype VI) sequences were detected in R. bursa in five (3.2%) of the pools, with similar prevalences in central and Mediterranean Anatolian provinces. JMTV was identified in four R. bursa and one Rhipicephalus turanicus pools, collected from Mediterranean and southeastern Anatolia, with a CCHFV and JMTV coinfected R. bursa pool. The JMTV segment 1 sequences formed a separate cluster with those from Turkey and the Balkan peninsula in the maximum likelihood analysis. TcTV-2 was detected in two Dermacentor marginatus specimens (1.3%) collected in central Anatolia, with nucleocapsid sequences forming a phylogenetically segregated group among viruses from humans and ticks from China and Kazakhstan. Discussion: CCHFV Europe 2 was initially documented in ticks from central Anatolian locations, where related orthonairoviruses had been previously recorded. Ongoing activity and a wider distribution of JMTV and TcTV-2 were observed. These viruses should be screened as potential etiological agents in human infections associated with tick bites.

Discovery and Surveillance of Tick-Borne Pathogens

Within the past 30 yr molecular assays have largely supplanted classical methods for detection of tick-borne agents. Enhancements provided by molecular assays, including speed, throughput, sensitivity, and specificity, have resulted in a rapid increase in the number of newly characterized tick-borne agents. The use of unbiased high throughput sequencing has enabled the prompt identification of new pathogens and the examination of tick microbiomes. These efforts have led to the identification of hundreds of new tick-borne agents in the last decade alone. However, little is currently known about the majority of these agents beyond their phylogenetic classification. Our article outlines the primary methods involved in tick-borne agent discovery and the current status of our understanding of tick-borne agent diversity.

Viromics of extant insect orders unveil the evolution of the flavi-like superfamily

Insects are the most diversified and species-rich group of animals and harbor an immense diversity of viruses. Several taxa in the flavi-like superfamily, such as the genus Flavivirus, are associated with insects; however, systematic studies on insect virus genetic diversity are lacking, limiting our understanding of the evolution of the flavi-like superfamily. Here, we examined the diversity of flavi-like viruses within the most complete and up-to-date insect transcriptome collection comprising 1,243 insect species by employing a Flaviviridae RdRp profile hidden Markov model search. We identified seventy-six viral sequences in sixty-one species belonging to seventeen insect, one entognathan, and one arachnidan orders. Phylogenetic analyses revealed that twenty-seven sequences fell within the Flaviviridae phylogeny but did not group with established genera. Despite the large diversity of insect hosts studied, we only detected one virus in a blood-feeding insect, which branched within the genus Flavivirus, indicating that this genus likely diversified only in hematophagous arthropods. Nine new jingmenviruses with novel host associations were identified. One of the jingmenviruses established a deep rooting lineage additional to the insect- and tick-associated clades. Segment co-segregation phylogenies support the separation of tick- and insect-associated groups within jingmenviruses, with evidence for segment reassortment. In addition, fourteen viruses grouped with unclassified flaviviruses encompassing genome length of up to 20 kb. Species-specific clades for Hymenopteran- and Orthopteran-associated viruses were identified. Forty-nine viruses populated three highly diversified clades in distant relationship to Tombusviridae, a plant-infecting virus family, suggesting the detection of three previously unknown insect-associated families that contributed to tombusvirus evolution.

Geographical and Tick-Dependent Distribution of Flavi-Like Alongshan and Yanggou Tick Viruses in Russia

The genus Flavivirus includes related, unclassified segmented flavi-like viruses, two segments of which have homology with flavivirus RNA-dependent RNA polymerase NS5 and RNA helicase-protease NS3. This group includes such viruses as Jingmen tick virus, Alongshan virus, Yanggou tick virus and others. We detected the Yanggou tick virus in Dermacentor nuttalli and Dermacentor marginatus ticks in two neighbouring regions of Russia. The virus prevalence ranged from 0.5% to 8.0%. We detected RNA of the Alongshan virus in 44 individuals or pools of various tick species in eight regions of Russia. The virus prevalence ranged from 0.6% to 7.8%. We demonstrated the successful replication of the Yanggou tick virus and Alongshan virus in IRE/CTVM19 and HAE/CTVM8 tick cell lines without a cytopathic effect. According to the phylogenetic analysis, we divided the Alongshan virus into two groups: an Ixodes persulcatus group and an Ixodes ricinus group. In addition, the I. persulcatus group can be divided into European and Asian subgroups. We found amino acid signatures specific to the I. ricinus and I. persulcatus groups and also distinguished between the European and Asian subgroups of the I. persulcatus group.

Diversity and circulation of Jingmen tick virus in ticks and mammals

Since its initial identification in ticks in 2010, Jingmen tick virus (JMTV) has been described in cattle, rodents, and primates. To better understand the diversity, evolution, and transmission of JMTV, we sampled 215 ticks, 104 cattle bloods, 216 bats, and 119 rodents in Wenzhou city, Zhejiang Province, China as well as 240 bats from Guizhou and Henan Provinces. JMTV was identified in 107 ticks (from two species), 54 bats (eleven species), 8 rodents (three species), and 10 cattle, with prevalence levels of 49.8, 11.8, 6.7, and 9.6 per cent, respectively, suggesting that bats may be a natural reservoir of JMTV. Phylogenetic analyses revealed that all the newly identified JMTVs were closely related to each other and to previously described viruses. Additionally, all tick and mammalian JMTV sampled in Wenzhou shared a consistent genomic structure, suggesting that the virus can cocirculate between ticks and mammals without observable variation in genome organization. All JMTVs sampled globally could be divided into two phylogenetic groups, Mantel tests suggested that geographic isolation, rather than host species, may be the main driver of JMTV diversity. However, the exact geographical origin of JMTV was difficult to determine, suggesting that this virus has a complex evolutionary history.

Detection of novel tick-borne pathogen, Alongshan virus, in Ixodes ricinus ticks, south-eastern Finland, 2019

The newly identified tick-borne Alongshan virus (ALSV), a segmented Jingmen virus group flavivirus, was recently associated with human disease in China. We report the detection of ALSV RNA in Ixodes ricinus ticks in south-eastern Finland. Screening of sera from patients suspected for tick-borne encephalitis for Jingmen tick virus-like virus RNA and antibodies revealed no human cases. The presence of ALSV in common European ticks warrants further investigations on its role as a human pathogen.

Isolation and Characterisation of Alongshan Virus in Russia

In recent decades, many new flavi-like viruses have been discovered predominantly in different invertebrates and, as was recently shown, some of them may cause disease in humans. The Jingmenvirus (JMV) group holds a special place among flaviviruses and flavi-like viruses because they have a segmented ssRNA(+) genome. We detected Alongshan virus (ALSV), which is a representative of the JMV group, in ten pools of adult Ixodes persulcatus ticks collected in two geographically-separated Russian regions. Three of the ten strains were isolated in the tick cell line IRE/CTVM19. One of the strains persisted in the IRE/CTVM19 cells without cytopathic effect for three years. Most ALSV virions purified from tick cells were spherical with a diameter of approximately 40.5 nm. In addition, we found smaller particles of approximately 13.1 nm in diameter. We obtained full genome sequences of all four segments of two of the isolated ALSV strains, and partial sequences of one segment from the third strain. Phylogenetic analysis on genome segment 2 of the JMV group clustered our novel strains with other ALSV strains. We found evidence for the existence of a novel upstream open reading frame in the glycoprotein-coding segment of ALSV and other members of the JMV group.

Proteomics Computational Analyses Suggest That the Envelope Glycoproteins of Segmented Jingmen Flavi-Like Viruses are Class II Viral Fusion Proteins (b-Penetrenes) with Mucin-Like Domains

Jingmen viruses are newly described segmented flavi-like viruses that have a worldwide distribution in ticks and have been associated with febrile illnesses in humans. Computational analyses were used to predict that Jingmen flavi-like virus glycoproteins have structural features of class II viral fusion proteins, including an ectodomain consisting of beta-sheets and short alpha-helices, a fusion peptide with interfacial hydrophobicity and a three-domain architecture. Jingmen flavi-like virus glycoproteins have a sequence enriched in serine, threonine, and proline at the amino terminus, which is a feature of mucin-like domains. Several of the serines and threonines are predicted be modified by the addition of O-linked glycans. Some of the glycoproteins are predicted to have an additional mucin-like domain located prior to the transmembrane anchor, whereas others are predicted to have a stem consisting of two alpha-helices. The flavivirus envelope protein and Jingmen flavi-virus glycoproteins may have diverged from a common class II precursor glycoprotein with a mucin-like domain or domains acquired after divergence.

Revisiting new tick-associated viruses: what comes next?

Tick-borne viral infections continue to cause diseases with considerable impact on humans, livestock, companion animals and wildlife. Many lack specific therapeutics and vaccines are available for only a few. Tick-borne viruses will continue to emerge, facilitated by anthroponotic factors related to the modern lifestyle. We persistently identify and are obliged to cope with new examples of emerging tick-borne viral diseases and novel viruses today. Many new strains have been detected in vertebrates and arthropods, some causing severe diseases likely to challenge public and veterinary health. This manuscript aims to provide a narrative overview of recently-described tick-associated viruses, with perspectives on changing paradigms in identification, screening and control.

Towards an Effective, Rational and Sustainable Approach for the Control of Cattle Ticks in the Neotropics

Ticks and transmitted pathogens constitute a major burden for cattle industry in the Neotropics. To address this limitation, the Spanish Ibero-American Program of Science and Technology in Development office (CYTED) supported from 2018 a network of scientists named “LaGar” (CYTED code 118RT0542) aimed at optimizing the control strategies of cattle ticks in the neotropical region. As part of network activities, a meeting and course were organized on 4–8 November 2019 in Querétaro, Mexico to address the objective of developing the infrastructure necessary for an effective, sustainable (i.e., combination of efficacious acaricides with anti-tick vaccines) and rational (i.e., considering tick ecology, seasonal dynamics and cattle-wildlife interactions) control of cattle tick infestations and transmitted pathogens. The course was focused on scientists, students, cattle holders and producers and pharmaceutical/industry representatives. In this way the course addressed the different views presented by participants with the conclusion of producing a research-driven combination of different interventions for the control of tick tick-borne diseases.

Survey and Characterization of Jingmen Tick Virus Variants

We obtained a Jingmen tick virus (JMTV) isolate, following inoculation of a tick pool with detectable Crimean-Congo hemorrhagic fever virus (CCHFV) RNA. We subsequently screened 7223 ticks, representing 15 species in five genera, collected from various regions in Anatolia and eastern Thrace, Turkey. Moreover, we tested specimens from various patient cohorts (n = 103), and canine (n = 60), bovine (n = 20) and avian specimens (n = 65). JMTV nucleic acids were detected in 3.9% of the tick pools, including those from several tick species from the genera Rhipicephalus and Haemaphysalis, and Hyalomma marginatum, the main vector of CCHFV in Turkey. Phylogenetic analysis supported two separate clades, independent of host or location, suggesting ubiquitous distribution in ticks. JMTV was not recovered from any human, animal or bird specimens tested. Near-complete viral genomes were sequenced from the prototype isolate and from three infected tick pools. Genome topology and functional organization were identical to the members of Jingmen group viruses. Phylogenetic reconstruction of individual viral genome segments and functional elements further supported the close relationship of the strains from Kosovo. We further identified probable recombination events in the JMTV genome, involving closely-related strains from Anatolia or China.

Molecular survey of flaviviruses and orthobunyaviruses in Amblyomma spp. ticks collected in Minas Gerais, Brazil

Due to anthropic environmental changes, vector-borne diseases are emerging worldwide. Ticks are known vectors of several pathogens of concern among humans and animals. In recent decades, several examples of tick-borne emerging viral diseases have been reported (Crimean Congo hemorrhagic fever virus, Powassan virus, encephalitis virus, heartland virus, severe fever with thrombocytopenia syndrome virus). Unfortunately, few studies addressing the presence of viruses in wild ticks have been carried out in South America. With the aim of detecting flaviviruses and orthobunyaviruses in ticks, we carried out molecular detection in wild ticks collected in the state of Minas Gerais, Brazil. No Flavivirus-positive ticks were detected; however, we detected activity of Orthobunyavirus in 8 Amblyomma tick specimens. One of those individuals was positive for Bunyamwera orthobunyavirus, which represents the first report of this virus among ticks in South America. Further studies related to the ecology of zoonotic diseases are needed to increase knowledge of this topic, including attempts at viral isolation, full genome sequencing and biological characterization. In this way, we will obtain a better picture of the real risk of ticks as a vector for viral diseases for humans and animals on our continent, where no tick-borne viral disease is known to occur.

Prevalence of the emerging novel Alongshan virus infection in sheep and cattle in Inner Mongolia, northeastern China

Background

Alongshan virus (ALSV) is a novel discovered segmented flavivirus associated with human febrile illness in northeastern China. Ixodes persulcatus is considered as a candidate vector of ALSV in the endemic regions. However, the role of domesticated animals in the circulation and transmission of ALSV have not been investigated. To evaluate the prevalence of ALSV infections in domesticated animals, viral RNA and viral specific antibodies were detected in sheep and cattle in Hulunbuir of northeastern Inner Mongolia. The findings contribute to the understanding of the ecology and transmission of ALSV among different natural hosts.

Methods

A total of 480 animal serum samples were collected in Hulunbuir of northeastern China in May, 2017. Viral specific antibodies were tested by indirect enzyme-linked immunosorbent assay (ELISA) with a purified E. coli recombinant capsid protein (VP2) of ALSV (strain H3) and further detected by viral neutralization test (VNT). RNA in serum samples were extracted and detected for ALSV sequence by quantitative real-time RT-PCR. ALSV RNA positive samples were used for virus isolation.

Results

ALSV-specific antibodies were detected in 9.2% (22/240) of examined sheep and 4.6% (11/240) of examined cattle by ELISA, while lower serological positivity with 4.2% (10/240) for sheep and 1.7% (4/240) for cattle was confirmed by VNT. In contrast, the prevalence of ALSV RNA was much higher, ranging from 26.3% (63/240) in sheep to 27.5% (66/240) in cattle. The partial S1 (NS5-like) and S3 (NS3-like) segments of ALSVs in sheep and cattle shared high identities of more than 98% to the human and tick isolates in the studied regions.

Conclusions

These results suggest that the natural infection of ALSV can be found in sheep and cattle in the endemic regions.

Viral Diversity of Tick Species Parasitizing Cattle and Dogs in Trinidad and Tobago

Ticks are vectors of a wide variety of pathogens that are implicated in mild to severe disease in humans and other animals. Nonetheless, the full range of tick-borne pathogens is unknown. Viruses, in particular, have been neglected in discovery efforts targeting tick-borne agents. High throughput sequencing was used to characterize the virome of 638 ticks, including Rhipicephalus microplus (n = 320), Rhipicephalus sanguineus (n = 300), and Amblyomma ovale (n = 18) collected throughout Trinidad and Tobago in 2017 and 2018. Sequences representing nine viruses were identified, including five novel species within Tymovirales, Bunyavirales, Chuviridae, Rhabdoviridae, and Flaviviridae. Thereafter the frequency of detection of viral sequences in individual tick species was investigated.