A tick-borne segmented RNA virus called Jingmen tick virus (JMTV) was recently identified, variants of which were detected in a non-human primate host and fatal patients with Crimean-Congo haemorrhagic fever. We investigated its infectivity and pathogenicity for humans. We obtained skin-biopsy, blood and serum samples from patients with tick bites, and used high-throughput sequencing, in situ hybridisation, and serologic testing to diagnose and ascertain the cases of JMTV infection. A JMTV strain was isolated from the tick Amblyomma javanense into an embryo-derived tick cell line. We obtained sustained passage of JMTV, and revealed that it was able to accumulate in salivary glands of experimentally infected ticks. Four JMTV-infected patients were identified by high-throughput sequencing of skin biopsies and blood samples. The virus replication in skin tissue was visualised by in situ hybridisation. The four patients all had an itchy or painful eschar at the site of tick bite, with or without lymphadenopathy. Immunohistochemical examination revealed remarkable local inflammation manifested as infiltration by neutrophils. Eight patients were identified by serological testing and showed more severe clinical manifestations. Two Ixodes persulcatus ticks detached from patients were positive for JMTV. All JMTV strains identified in this study formed a well-supported sub-lineage, distinct from those previously reported in China. Interpretation The public significance of JMTV should be highly concerning due to its potential pathogenicity for humans and efficient transmission by potential ticks. FUND: China Natural Science Foundation, State Key Research Development Programme, and United Kingdom Biotechnology and Biological Sciences Research Council.

The increasing prevalence and expanding distribution of tick-borne viruses globally have raised health concerns, but the full repertoire of the tick virome has not been assessed. We sequenced the meta-transcriptomes of 31 different tick species in the Ixodidae and Argasidae families from across mainland China, and identified 724 RNA viruses with distinctive virome compositions among genera. A total of 1,801 assembled and complete or nearly complete viral genomes revealed an extensive diversity of genome architectures of tick-associated viruses, highlighting ticks as a reservoir of RNA viruses. We examined the phylogenies of different virus families to investigate virome evolution and found that the most diverse tick-associated viruses are positive-strand RNA virus families that demonstrate more ancient divergence than other arboviruses. Tick-specific viruses are often associated with only a few tick species, whereas virus clades that can infect vertebrates are found in a wider range of tick species. We hypothesize that tick viruses can exhibit both ‘specialist’ and ‘generalist’ evolutionary trends. We hope that our virome dataset will enable much-needed research on vertebrate-pathogenic tick-associated viruses.

We recently detected a HKU4-related coronavirus in subgenus Merbecovirus (named pangolin-CoV-HKU4-P251T) from a Malayan pangolin¹. Here we report isolation and characterization of pangolin-CoV-HKU4-P251T, the genome sequence of which is closest to that of a coronavirus from the greater bamboo bat (Tylonycteris robustula) in Yunnan Province, China, with a 94.3% nucleotide identity. Pangolin-CoV-HKU4-P251T is able to infect human cell lines, and replicates more efficiently in cells that express human-dipeptidyl-peptidase-4 (hDPP4)-expressing and pangolin-DPP4-expressing cells than in bat-DPP4-expressing cells. After intranasal inoculation with pangolin-CoV-HKU4-P251, hDPP4-transgenic female mice are likely infected, showing persistent viral RNA copy numbers in the lungs. Progressive interstitial pneumonia developed in the infected mice, characterized by the accumulation of macrophages, and increase of antiviral cytokines, proinflammatory cytokines, and chemokines in lung tissues. These findings suggest that the pangolin-borne HKU4-related coronavirus has a potential for emerging as a human pathogen by using hDPP4.

Ticks are arthropod vectors capable of transmitting a wide spectrum of pathogens affecting humans and animals. However, we have relatively limited information of their genomic characteristics and the diversity of associated microbiomes. Here we used long- and short-read sequencing on 1,479 samples from 48 tick species across eight genera from China to determine their genome and associated pathogens and microbiome. Through de novo assembly, we reconstructed 7,783 bacterial genomes representing 1,373 bacterial species, of which, 712 genomes represented 32 potentially pathogenic species. Computational analysis found nutritional endosymbionts to be prevalent and highly specific to tick genera. The microbiome genome-wide association study revealed host genetic variants linked to pathogen diversity, abundance and key biological pathways essential to tick biology, including blood-feeding and pathogen invasion. These findings provide a resource for studying the host–microbe interactions within ticks, paving the way for strategies to control tick populations and tick-borne diseases.

Emerging tick-borne infectious diseases have become increasingly prevalent worldwide. In a previous review, we summarized tick-borne infections in mainland China from 1980 to May, 2015. Here we conducted systematic review and mapping analysis of emerging tick-borne diseases over the past decade. We searched multiple sources for publications regarding tick-borne diseases in mainland China from June, 2015 to January, 2025. Subsequently, we collected data on tick infections of related pathogens from secondary literature review, GenBank, and our field survey, without time limitation. The clinical manifestations of each kind of tick-borne diseases were summarized. The thematic maps showing geographical distribution of emerging tick-borne diseases and related tick infections were produced by ArcGIS. Over the past decade, 28 emerging tick-borne diseases have been identified in mainland China, including 11 viral diseases, ten rickettsiosis, one anaplasmosis, one ehrlichiosis, two spirochetal diseases, and three protozoan diseases. These emerged diseases, caused by diverse pathogens, exhibit distinct geographic distribution patterns. Clinically, they are primarily characterized by febrile and non-specific symptoms, underscoring the importance of pathogen-specific diagnostic methods for accurate diagnosis. The tick-borne pathogens responsible for these emerging diseases were identified in 40 tick species and more widely distributed across China, implying cases of the emerging tick-borne diseases underdiagnosed. Emerging tick-borne diseases have become an unprecedented public health threat in mainland China. Increased awareness and enhanced surveillance are required to understand the burden of tick-borne diseases in China and countries where tick vectors are present. 10.13039/501100012166 National Key Research and Development Program of China .