Haemaphysalis Longicornis Research Articles

The genome-wide characterization and associated cold-tolerance function of the superoxide dismutase in the cold response of the tick Haemaphysalis longicornis

Accumulating evidence suggests that superoxide dismutase (SOD) is the first line of antioxidant defense in organisms and plays an important role in scavenging reactive oxygen species produced during environmental stress. However, limited information is available regarding the response of SOD genes to cold stress in ticks. Therefore, in the present study, SOD genes were cloned and identified from the genome of Haemaphysalis longicornis, and the function of SOD during the cold response was further explored. Seven SOD genes were characterized: HlCCS1, HlCCS2, HlMSD, HlCSD1, HlCSD2, HlCSD3, and HlCSD4. Bioinformatics analysis showed that HlCCS1 and HlCCS2 are copper chaperones of SODs. HlCSD1–HlCSD4 belong to the Cu/Zn SOD, whereas HlMSD belongs to the Mn SOD gene family. Fluorescence quantitative PCR showed that the expression of HlCCS2, HlMSD, and HlCSD1–3 was upregulated, whereas HlCCS1 and HlCSD4 were downregulated during the cold response of H. longicornis. Western blotting confirmed changes in the relative expression of HlCSD3 and HlMSD in H. longicornis after cold treatment. Mortality of H. longicornis increased significantly after dsRNA injection of HlCCS2, HlMSD, HlCSD1, and HlCSD3. The above results show that SODs have different regulatory functions during the cold response in H. longicornis, and there might be an interaction between treatment temperature and duration. Furthermore, the results lay a foundation for subsequent research on the molecular mechanism of cold tolerance in H. longicornis and shed light on the population distribution and diffusion limit of ticks.

An established population of Asian longhorned ticks (Acari: Ixodidae) in Ohio, USA.

We describe the first known established Asian longhorned tick (ALT) (Acari: Ixodidae: Haemaphysalis longicornis Neumann) population in Ohio, USA. In mid-summer 2021, we collected ALTs from an infested pasture in response to an alert that grazing cattle had been infested with ticks, and 3 of them had died. No ALTs were reported following pesticide treatment of the pasture in fall 2021. In the laboratory, we identified 9,287 ticks to species, representing all 3 life stages, as ALTs and tested 100 of the adult females for infectious agents relevant to human and animal health, including Theileria orientalis, a cattle disease agent. Eight field-collected ticks were positive for Anaplasma phagocytophilum (n = 100, 8%); no other infectious agents were detected. Active environmental surveillance showed the return of ALTs in June 2022 despite the tick control efforts in 2021. As ALTs continue to expand their range in the United States, active and passive surveillance studies will be needed to characterize their evolving role in human and animal health.

Host, season, habitat and climatic factors as drivers of Asian rodent tick (Ixodes granulatus) (Acari: Ixodidae) occurrence and abundance in Southeast Asia

The Asian rodent tick (Ixodes granulatus) occurs throughout much of Asia, it frequently bites humans, and zoonotic pathogens, such as Borrelia burgdorferi (sensu lato) and Rickettsia honei, have been detected within it. Unfortunately, the ecology of I. granulatus remains poorly known, including drivers of its abundance and the interaction ecology with its sylvatic hosts. To elucidate the ecology of this medically important species, the habitat preferences of I. granulatus were assessed in Singapore and Malaysia. Ixodes granulatus showed strong associations with old forest habitats, though across different age classes of old forest there was limited variation in abundance. Ixodes granulatus was absent from other habitats including young forest, scrubland, and parks/gardens. Within its sylvatic rodent hosts, a range of factors were found to be statistically significant predictors of I. granulatus load and/or infestation risk, including sex and body condition index. Male rodents were significantly more likely to be infested and to have higher loads than females, similarly, animals with a lower body condition index were significantly more likely to be infested. Proactive public health efforts targeted at preventing bites by this tick should carefully consider its ecology to minimise ecological overlap between humans and I. granulatus.

Heartland Virus: An Evolving Story of an Emerging Zoonotic and Vector-Borne Disease

Heartland virus (HRTV) is an emerging tick-borne bandavirus that is capable of causing severe disease characterized by acute thrombocytopenia and lymphopenia. The virus is endemic to the eastern United States and is carried by the Lone Star tick (Amblyomma americanum). Since its discovery in 2009, at least 60 human infections have been recorded across this area, with an overall 5–10% estimated mortality rate. All infections reported thus far have occurred following a known tick bite or exposure to tick-infested areas, but the possibility of nosocomial transmission has not been ruled out. Despite relatively high rates of seroprevalence among certain wildlife species such as white-tailed deer, the reservoir species for HRTV remains unknown, as the virus has never been isolated from any mammalian wildlife species. Furthermore, how the virus is transmitted to its vector species in nature remains unknown, though laboratory studies have confirmed both horizontal and vertical transmission of HRTV in A. americanum. In addition, the recent 2017 introduction of the Asian longhorned tick (Haemaphysalis longicornis) to the US has raised concerns about possible spillover of HRTV into a new tick species that has been confirmed to be a competent vector for HRTV in the laboratory. Thus, an increased awareness of its clinical presentation is needed, and further research is urgently required to establish the natural transmission cycle and develop new countermeasures for this novel zoonotic pathogen.

Ticks (Acari: Ixodida) on synanthropic small and medium-sized mammals in areas of the northeastern United States infested with the Asian longhorned tick, Haemaphysalis longicornis

The northeastern United States (US) is a hotspot for tick-borne diseases. Adding to an already complex vector landscape, in 2017 large populations of the invasive Haemaphysalis longicornis, the Asian longhorned tick, were detected in New Jersey (NJ) and later found to be widespread from Connecticut to Georgia. In its native range in northeastern Asia, H. longicornis is considered an important vector of deadly pathogens to humans, companion animals, and livestock. To identify the primary hosts of H. longicornis, we surveyed synanthropic small and medium-sized mammals in three different sites in suburban New Brunswick, NJ. Specifically, we collected approximately 9,000 tick specimens belonging to nine species from 11 different species of mammals sampled between May and September 2021. We found that H. longicornis feeds more frequently on rodents than previously thought, and that this invasive tick is likely exposed to important enzootic and zoonotic pathogens. Overall, we obtained detailed information about the seasonal dynamics and feeding patterns of six tick species common in the northeastern US, Haemaphysalis longicornis, Amblyomma americanum, Dermacentor variabilis, Ixodes scapularis, Ixodes texanus and Ixodes cookei. We found that unlike I. scapularis that feeds on mammals of all sizes, H. longicornis feeds on hosts following the general pattern of A. americanum, favoring larger species such as skunks, groundhogs, and raccoons. However, our survey revealed that unlike A. americanum, H. longicornis reaches high densities on Virginia opossum. Overall, the newly invasive H. longicornis was the most numerous tick species, both on multiple host species and in the environment, raising significant questions regarding its role in the epidemiology of tick-borne pathogens, especially those affecting livestock, companion animals and wildlife. In conclusion, our findings provide valuable insights into the tick species composition on mammalian hosts in NJ and the ongoing national expansion of H. longicornis.

EVIDENCE OF PROTOZOAN AND BACTERIAL INFECTION AND CO-INFECTION AND PARTIAL BLOOD FEEDING IN THE INVASIVE TICK HAEMAPHYSALIS LONGICORNIS IN PENNSYLVANIA.

The Asian longhorned tick, Haemaphysalis longicornis, an invasive tick species in the United States, has been found actively host-seeking while infected with several human pathogens. Recent work has recovered large numbers of partially engorged, host-seeking H. longicornis, which together with infection findings raises the question of whether such ticks can reattach to a host and transmit pathogens while taking additional bloodmeals. Here we conducted molecular blood meal analysis in tandem with pathogen screening of partially engorged, host-seeking H. longicornis to identify feeding sources and more inclusively characterize acarological risk. Active, statewide surveillance in Pennsylvania from 2020 to 2021 resulted in the recovery of 22/1,425 (1.5%) partially engorged, host-seeking nymphal and 5/163 (3.1%) female H. longicornis. Pathogen testing of engorged nymphs detected 2 specimens positive for Borrelia burgdorferi sensu lato, 2 for Babesia microti, and 1 co-infected with Bo. burgdorferi s.l. and Ba. microti. No female specimens tested positive for pathogens. Conventional PCR blood meal analysis of H. longicornis nymphs detected avian and mammalian hosts in 3 and 18 specimens, respectively. Mammalian blood was detected in all H. longicornis female specimens. Only 2 H. longicornis nymphs produced viable sequencing results and were determined to have fed on black-crowned night heron, Nycticorax nycticorax. These data are the first to molecularly confirm H. longicornis partial blood meals from vertebrate hosts and Ba. microti infection and co-infection with Bo. burgdorferi s.l. in host-seeking specimens in the United States, and the data help characterize important determinants indirectly affecting vectorial capacity. Repeated blood meals within a life stage by pathogen-infected ticks suggest that an understanding of the vector potential of invasive H. longicornis populations may be incomplete without data on their natural host-seeking behaviors and blood-feeding patterns in nature.

Baseline Susceptibility of Haemaphysalis longicornis to Organophosphate, Carbamate, and Pyrethroid Acaricides.

The Asian longhorned tick, Haemaphysalis longicornis, continues to expand its range in North America, and synthetic acaricides are likely to play an increasing role in managing this species. Acaricide resistance is common in some tick species that infest livestock. However, baseline acaricide susceptibility has not previously been examined in this invasive tick. We used a standard larval packet test to evaluate the susceptibility of the Asian longhorned tick to acaricides currently or formerly used in tick control: propoxur, carbaryl, bifenthrin, permethrin, and coumaphos. Discriminating concentrations were estimated at 6.5, 27.9, 988, 2242, and 808 ppm, respectively. The LC50 for propoxur, carbaryl, permethrin and coumaphos were compared with data available for other tick species and showed that H. longicornis was more susceptible to propoxur, carbaryl, and coumaphos and had a similar susceptibility to permethrin. The results indicate that resistance to these acaricides is not presently a concern for H. longicornis in the United States. However, responsible integrated management and early detection of resistance can help ensure the long-term efficacy of products used for controlling this tick species. This article is protected by copyright. All rights reserved.

Epidemiological characteristics of tick-borne infectious diseases in Hubei Province, 2016-2021

Objective: To understand the epidemiological characteristics of tick-borne infectious diseases (TBID) and the risk factors of severe illness and death in Hubei Province from 2016 to 2021. Methods: Based on the incidence data of fever with thrombocytopenia syndrome (SFTS), tsutsugamushi disease, typhus and other TBID reported during 2016-2021, the epidemiological analysis was conducted. Field investigation results of TBID in areas with high incidence in 2021, logistic regression analysis of population characteristics, epidemiological history and other factors were used to explore the risk factors of severe and fatal cases. In the field vector investigation, free ticks and surface ticks of the host animals in the cases' home and surrounding grassland were monitored and detected. Results: A total of 3 826 TBID cases were reported in Hubei from 2016 to 2021, of which 71.30% (2 728/3 826) were SFTS, 13.04% (499/3 826) were tsutsugamushi disease and 15.66% (599/3 826) were typhus. A total of 44 cases died in 6 years; the fatality rate was 1.15% (44/3 826). In the peak seasons of incidence from May to July, the cases in people engaged in agriculture related work accounted for 84.61% (3 237/3 826). The incidence rate in women was higher than that in men, and the cases aged ≥50 years accounted for 81.02% of the total (3 100/3 826), and the incidence rate increased with age (P<0.001). The TBID cases were distributed in 86 counties and districts in 16 prefectures (municipality). The incidence rates of different areas had significant differences (P<0.05), and there was a certain spatial-temporal clustering and expasion. Bovis microplus and Haemaphysalis longicornis were captured in the field, and the positive rates in host animals and grassland ticks were 10.94% (7/64) and 40.00% (2/5), respectively. Univariate logistic regression analysis results showed that age ≥50 years and leukocyte <2.0×109/L were risk factors for severe illness and death. Conclusions: The TBID reported in Hubei were mainly SFTS, tsutsugamushi disease and typhus. In order to reduce the incidence of TBID, it is necessary to strengthen the prevention and control in women aged ≥50 years and reduce field exposure and tick bites during the epidemic period.

Exploration of Multi-Gene DNA Barcode Markers to Reveal the Broad Genetic Diversity of Field Ticks (Acari: Ixodidae) in a Tropical Environment of Hainan Island, China

Ticks are hematophagous arthropods and obligate ectoparasites of humans and other animals. This study focused on the molecular discrimination of ticks in the tropical environment of Hainan according to multi-gene DNA barcode markers with the expectation of accurately distinguishing species. A total of 420 ticks, including 49 adult ticks, 203 nymphal ticks, and 168 larval ticks, were collected in the field, and the 49 adult ticks were identified as Rhipicephalus turanicus, Dermacentor marginatus, and Haemaphysalis longicornis. The mitochondrial 16S rRNA, ribosomal 28S rRNA D2, and ribosomal internal transcribed spacer 2 (ITS2) regions were used as DNA barcode markers to discriminate species. According to basic local alignment search tool analysis against the GenBank database, 16S rRNA positively identified ticks in the Rhipicephalus, Dermacentor, and Haemaphysalis genera; the 28S rRNA D2 region identified ticks in the Rhipicephalus and Dermacentor genera; and ITS2 identified ticks as D. marginatus. Pairwise sequence comparisons based on these three regions were visualized with a Sequence Demarcation Tool matrix. Substitution saturation tests using data analysis and molecular biology and evolution revealed little substitution saturation (Iss < Iss.c, p < 0.05) in the 16S rRNA region for the Haemaphysalis genus; 28S rRNA D2 region for the Rhipicephalus, Dermacentor, and Haemaphysalis genera; and ITS2 region for the Rhipicephalus and Dermacentor genera. Distinctive sequences for which it is difficult to obtain good matches with the sequences available in GenBank exist in the ticks of Hainan. Future studies should obtain complementary sequences to refine and update the database for the molecular characterization of ticks.

RNA activation in ticks

RNA activation (RNAa) is a burgeoning area of research in which double-stranded RNAs (dsRNAs) or small activating RNAs mediate the upregulation of specific genes by targeting the promoter sequence and/or AU-rich elements in the 3′- untranslated region (3’-UTR) of mRNA molecules. So far, studies on the phenomenon have been limited to mammals, plants, bacteria, Caenorhabditis elegans, and recently, Aedes aegypti. However, it is yet to be applied in other arthropods, including ticks, despite the ubiquitous presence of argonaute 2 protein, which is an indispensable requirement for the formation of RNA-induced transcriptional activation complex to enable a dsRNA-mediated gene activation. In this study, we demonstrated for the first time the possible presence of RNAa phenomenon in the tick vector, Haemaphysalis longicornis (Asian longhorned tick). We targeted the 3ʹ-UTR of a novel endochitinase-like gene (HlemCHT) identified previously in H. longicornis eggs for dsRNA-mediated gene activation. Our results showed an increased gene expression in eggs of H. longicornis endochitinase-dsRNA-injected (dsHlemCHT) ticks on day-13 post-oviposition. Furthermore, we observed that eggs of dsHlemCHT ticks exhibited relatively early egg development and hatching, suggesting a dsRNA-mediated activation of the HlemCHT gene in the eggs. This is the first attempt to provide evidence of RNAa in ticks. Although further studies are required to elucidate the detailed mechanism by which RNAa occurs in ticks, the outcome of this study provides new opportunities for the use of RNAa as a gene overexpression tool in future studies on tick biology, to reduce the global burden of ticks and tick-borne diseases.

Molecular Detection of Anaplasma, Ehrlichia and Rickettsia Pathogens in Ticks Collected from Humans in the Republic of Korea, 2021.

Tick-borne pathogens (TBPs), transmitted by the bites of ticks, are of great medical and veterinary importance. They include bacteria, viruses, and protozoan parasites. To provide fundamental data on the risk of tick contact and public health strategies, we aimed to perform a molecular investigation on four tick-borne bacterial pathogens in ticks collected from humans across the Republic of Korea (ROK) in 2021. In total, 117 ticks were collected, including Haemaphysalis longicornis (56.4%), Amblyomma testudinarium (26.5%), Ixodes nipponensis (8.5%), H. flava (5.1%), and I. persulcatus (0.9%). Among the ticks, 20.5% (24/117) contained tick-borne bacterial pathogens, with infection rates of 17.9% for Rickettsia (Candidatus Rickettsia jingxinensis, R. tamurae, R. monacensis, and Candidatus Rickettsia tarasevichiae), 2.5% for Anaplasma (A. phagocytophilum, A. capra, and A. bovis), and 0.9% for Ehrlichia (Ehrlichia sp.). Additionally, the co-detection rate for R. monacensis and A. phagocytophilum was 0.9%. To our knowledge, this is the first report of A. capra and A. bovis detection in ticks collected from humans in the ROK. This study contributes to the understanding of the potential risk of tick contact and provides fundamental data for establishing a public health strategy for tick-borne disease management in the ROK.

Characterization of bacterial communities in ticks parasitizing cattle in a touristic location in southwestern China

The purpose of this study was to investigate tick species around Mount Fanjing and analyze bacterial communities in two species – Rhipicephalus microplus and Haemaphysalis longicornis – parasitizing cattle in Tongren, Guizhou province, Southwest China, using high-throughput sequencing methods. In April 2019, ticks were collected from five sites in Jiangkou County, Yinjiang County, and Songtao County. In total, 296 ticks were collected, comprising two genera and three species: H. longicornis, Haemaphysalis flava, and R. microplus. Rhipicephalus microplus was the most representative species (57.4%) within the collected group, being the dominant species in Tongren City, followed by H. longicornis (39.5%) and H. flava (3.0%). Beta-diversity analysis revealed differences in bacterial community composition among the tick species. The bacterial community structure of R. microplus collected in the three counties was highly similar. Chlorella and Bacillus were highly abundant in H. longicornis. Rickettsia was detected at high relative abundance in R. microplus but in low relative abundance in H. longicornis, suggesting that Rickettsia is more associated with R. microplus than with H. longicornis. More in-depth investigations are needed to determine the pathogenic risk of Rickettsia and its relationship with the host. This is the first survey on tick-borne bacterial communities in this area, which is of great significance for the prevention and control of tick-borne diseases locally.

Molecular Detection of Tick-Borne Bacterial and Protozoan Pathogens in Haemaphysalis longicornis (Acari: Ixodidae) Ticks from Free-Ranging Domestic Sheep in Hebei Province, China.

Ticks and tick-borne pathogens significantly threaten human and animal health worldwide. Haemaphysalis longicornis is one of the dominant tick species in East Asia, including China. In the present study, 646 Ha. longicornis ticks were collected from free-ranging domestic sheep in the southern region of Hebei Province, China. Tick-borne pathogens of zoonotic and veterinary importance (i.e., Rickettsia, Anaplasma, Ehrlichia, Borrelia, Theileria, and Hepatozoon spp.) were detected in the ticks using PCR assays and sequence analysis. The prevalence rates of these pathogens were 5.1% (33/646), 15.9% (103/646), 1.2% (8/646), 17.0% (110/646), 0.15% (1/646), and 0.15% (1/646), respectively. For Rickettsia spp., R. japonica (n = 13), R. raoultii (n = 6), and Candidatus R. jingxinensis (n = 14) were detected for the first time in the province, while several Anaplasma spp. were also detected in the ticks, including A. bovis (n = 52), A. ovis (n = 31), A. phagocytophilum (n = 10), and A. capra (n = 10). A putative novel Ehrlichia spp. was also found with a prevalence of 1.2% in the area. The present study provides important data for effectively controlling ticks and tick-borne diseases in the Hebei Province region of China.

Molecular characterization and immune efficacy of fructose-1,6-bisphosphate aldolase from Haemaphysalis longicornis (Acari: Ixodidae)

BackgroundTicks are obligate hematophagous ectoparasites that transmit a variety of pathogens to humans, wildlife and domestic animals. Vaccination is an effective and environmentally friendly method for tick control. Fructose-1,6-bisphosphate aldolase (FBA) is an important glycometabolism enzyme that is a candidate vaccine against parasites. However, the immune protection of FBA in ticks is unclear.Methods and resultsThe 1092-bp open reading frame (ORF) of FBA from Haemaphysalis longicornis (HlFBA), encoding a 363-amino acid protein, was cloned using PCR methodology. The prokaryotic expression vector pET32a(+)-HlFBA was constructed and transformed into cells of Escherichia coli BL21(DE3) strain for protein expression. The recombinant HlFBA protein (rHlFBA) was purified by affinity chromatography, and the western blot results suggested that the rHlFBA protein was immunogenic.ResultsResults of the enzyme-linked immunosorbent assay showed that rabbits immunized with rHlFBA produced a humoral immune response specific to rHlFBA. A tick infestation trial indicated that, compared to the ticks in the histidine-tagged thioredoxin (Trx) group, the engorged tick weight and oviposition of female ticks and egg hatching rate of those in the rHlFBA group was reduced by 22.6%, 45.6% and 24.1%, respectively. Based on the cumulative effect of the these three parameters, the overall immune efficacy of rHlFBA was estimated to be 68.4%.ConclusionsFBA is a candidate anti-tick vaccine that can significantly reduce the engorged tick weight, oviposition, and egg hatching rate. The use of enzymes involved in glucose metabolism is a new strategy in the development of anti-tick vaccines.Graphical

Effects of histamine and antihistamine on the hard tick Haemaphysalis longicornis during blood sucking.

At the time of host attachment, ticks are very sensitive to histamine, but during rapid blood sucking they paradoxically require histamine. Using a rabbit model, we studied the effects of histamine and antihistamine during attachment and fast-feeding in different life stages of Haemaphysalis longicorns. We examined how they responded to histamine and antihistamine by analyzing the detachment rate, histology of feeding lesions, and post-feeding behavior. A significant difference (P&lt;0.01) was found in the detachment rate between experimental and control treatments throughout the observation period. Ticks exhibited a higher detachment rate (30.1%) at 12 h after histamine application during attachment time and on antihistamine-treated skin (25.4%) at 96 h during fast-feeding. After feeding on histamine-treated rabbits, the fully engorged body weights of larvae and nymphs were 0.7±0.36 mg and 3.5±0.65 mg, respectively. An average increase in body weight of 0.6±0.05 mg and 3.2±0.30 mg was observed for larvae and nymphs compared to the respective control weights. Nymphs and adults engorged after antihistamine treatment had an average body weight of 1.3±0.54 mg and 54±0.81 mg, respectively. An average decrease in body weight was observed in antihistamine-treated H. longicornis compared with control nymphs (3.3±0.42 mg) and adults (174±1.78 mg). Skin biopsies were collected after treatment, and differential histopathological characteristics were found between the treatment and control groups. Tick-infested skin collected from rabbits in the antihistamine-treated group lacked erythrocytes in the feeding pool, indicating that antihistamine impaired tick fast-feeding stage.

The tick saliva peptide HIDfsin2 promotes the tick-borne virus SFTSV replication in vitro by enhancing p38 signal pathway.

Pathogens co-evolved with ticks to facilitate blood collection and pathogen transmission. Although tick saliva was recently found to be rich in bioactive peptides, it is still elusive which saliva peptide promotes virus transmission and which pathways are invovled. Here, we used a saliva peptide HIDfsin2 and a severe fever with thrombocytopenia syndrome virus (SFTSV) both carried by the tick Haemaphysalis longicornis to elucidate the relationship between tick saliva components and tick-borne viruses. HIDfsin2 was found to promote the replication of SFTSV in a dose-dependent manner in vitro. HIDfsin2 was further revealed to MKK3/6-dependently magnify the activation of p38 MAPK. The overexpression, knockdown and phosphorylation site mutation of p38α indicated that p38 MAPK activation facilitated SFTSV infection in A549 cells. Moreover, the blockade of p38 MAPK activation significantly suppressed SFTSV replication. Differently, HIDfsin2 or pharmacological inhibition of p38 MAPK activation had no effect on a mosquito-borne Zika virus (ZIKV). All these results showed that HIDfsin2 specifically promoted SFTSV replication through the MKK3/6-dependent enhancement of p38 MAPK activation. Our study provides a new perspective on the transmission of tick-borne viruses under natural conditions, and supports that the blockade of p38 MAPK activation can be a promising strategy against the mortal tick-borne virus SFTSV.

Detection of viral genes in Metarhizium anisopliae JEF-290-infected longhorned tick, Haemaphysalis longicornis using transcriptome analysis

Ticks are carriers of viruses that can cause disease in humans and animals. The longhorned ticks (Haemaphysalis longicornis; LHT), for example, mediates the severe fever with thrombocytopenia syndrome virus (SFTSV) in humans, and the population of ticks is growing due to increases in temperature caused by climate change. As ticks carry primarily RNA viruses, there is a need to study the possibility of detecting new viruses through tick virome analysis. In this study, viruses in LHTs collected in Korea were investigated and virus titers in ticks exposed to the entomopathogenic fungus Metarhizium anisopliae JEF-290 were analyzed. Total RNA was extracted from the collected ticks, and short reads were obtained from Illumina sequencing. A total of 50,024 contigs with coding capacity were obtained after de novo assembly of the reads in the metaSPAdes genome assembler. A series of BLAST-based analyses using the GenBank database was performed to screen viral contigs, and three putative virus species were identified from the tick meta-transcriptome, such as Alongshan virus (ALSV), Denso virus and Taggert virus. Measurements of virus-expression levels of infected and non-infected LHTs failed to detect substantial differences in expression levels. However, we suggest that LHT can spread not only SFTSV, but also various other disease-causing viruses over large areas of the world. From the phylogenetic analysis of ALSV glycoproteins, genetic differences in the ALSV could be due to host differences as well as regional differences. Viral metagenome analysis can be used as a tool to manage future outbreaks of disease caused by ticks by detecting unknown viruses.

Diversity Analysis of Tick-Borne Viruses from Hedgehogs and Hares in Qingdao, China.

Tick-borne viruses (TBVs) have attracted increasingly global public health attention. In this study, the viral compositions of five tick species, Haemaphysalis flava, Rhipicephalus sanguineus, Dermacentor sinicus, Haemaphysalis longicornis, and Haemaphysalis campanulata, from hedgehogs and hares in Qingdao, China, were profiled via metagenomic sequencing. Thirty-six strains of 10 RNA viruses belonging to 4 viral families, including 3 viruses of Iflaviridae, 4 viruses of Phenuiviridae, 2 viruses of Nairoviridae, and 1 virus of Chuviridae, were identified in five tick species. Three novel viruses of two families, namely, Qingdao tick iflavirus (QDTIFV) of the family of Iflaviridae and Qingdao tick phlebovirus (QDTPV) and Qingdao tick uukuvirus (QDTUV) of the family of Phenuiviridae, were found in this study. This study shows that ticks from hares and hedgehogs in Qingdao harbored diverse viruses, including some that can cause emerging infectious diseases, such as Dabie bandavirus. Phylogenetic analysis revealed that these tick-borne viruses were genetically related to viral strains isolated previously in Japan. These findings shed new light on the cross-sea transmission of tick-borne viruses between China and Japan. IMPORTANCE Thirty-six strains of 10 RNA viruses belonging to 4 viral families, including 3 viruses of Iflaviridae, 4 viruses of Phenuiviridae, 2 viruses of Nairoviridae, and 1 virus of Chuviridae, were identified from five tick species in Qingdao, China. A diversity of tick-borne viruses from hares and hedgehogs in Qingdao was found in this study. Phylogenetic analysis showed that most of these TBVs were genetically related to Japanese strains. These findings indicate the possibility of the cross-sea transmission of TBVs between China and Japan.

New York State Tick Blitz: harnessing community-based science to understand range expansion of ticks.

Ticks and tick-borne diseases are an immense public health burden in New York State (NYS), United States. Tick species and associated pathogens are expanding into new areas, shifting threats to human, and animal health across the state. For example, the invasive tick, Haemaphysalis longicornis Neumann (Acari: Ixodidae), was first detected in the United States in 2017 and has since been identified in 17 states, including NYS. In addition, Amblyomma americanum (L.) (Acari: Ixodidae) is a native tick thought to be reestablishing historical populations in NYS. We implemented a community-based science project called the "NYS Tick Blitz" to determine the distribution of A. americanum and H. longicornis in NYS. Community volunteers were recruited, provided with education, training, and materials to conduct active tick sampling during a 2-wk period in June 2021. Fifty-nine volunteers sampled 164 sites across 15 counties, for a total of 179 separate collection events and 3,759 ticks collected. The most frequently collected species was H. longicornis, followed by Dermacentor variabilis Say (Acari: Ixodidae), Ixodes scapularis Say (Acari: Ixodidae), and A. americanum, respectively. Through the NYS Tick Blitz collections, H. longicornis was identified for the first time in Putnam County. We conducted pooled pathogen testing on a subset of specimens, with the highest rates of infection detected for pathogens transmitted by I. scapularis, including Borrelia burgdorferi, Anaplasma phagocytophilum, and Babesia microti. Most participants who completed a follow-up survey (n = 23, 71.9%) were promoters of the NYS Tick Blitz and 50% (n = 15) reported that they enjoyed participating in meaningful science.

A U.S. Isolate of Theileria orientalis Ikeda Is Not Transstadially Transmitted to Cattle by Rhipicephalus microplus.

Theileria orientalis Ikeda has caused an epidemic of bovine anemia and abortion across several U.S. states. This apicomplexan hemoparasite is transmitted by Haemaphysalis longicornis ticks; however, it is unknown if other North American ticks are competent vectors. Since the disease movement is largely determined by the host tick range(s), the prediction of the T. orientalis spread among U.S. cattle populations requires determination of additional competent tick vectors. Although Rhipicephalus microplus has mostly been eradicated from the U.S., outbreaks in populations occur frequently, and the U.S. remains at risk for reintroduction. Since R. microplus is a vector of Theileria equi and T. orientalis DNA has been detected in R. microplus, the goal of this study was to determine whether R. microplus is a competent vector of T. orientalis. Larval R. microplus were applied to a splenectomized, T. orientalis Ikeda-infected calf for parasite acquisition, removed as molted adults, and applied to two T. orientalis naïve, splenectomized calves for transmission. After 60 days, the naïve calves remained negative for T. orientalis by PCR and cytology. Additionally, T. orientalis was not detected in the salivary glands or larval progeny of acquisition-fed adults. These data suggest that R. microplus is not a competent vector of the U.S. T. orientalis Ikeda isolate.