OBJECTIVE: Poxviruses are zoonotic pathogens that infect humans, mammals, vertebrates, and arthropods. However, the specific role of ticks in transmission and evolution of these viruses remains unclear. METHODS: Transcriptomic and metatranscriptomic raw data from 329 sampling pools of seven tick species across five continents were mined to assess the diversity and abundance of poxviruses. Chordopoxviral sequences were assembled and subjected to phylogenetic analysis to trace the origins of the unblasted fragments within these sequences. RESULTS: Fifty-eight poxvirus species, representing two subfamilies and 20 genera, were identified, with 212 poxviral sequences assembled. A substantial proportion of AT-rich fragments were detected in the assembled poxviral genomes. These genomic sequences contained fragments originating from rodents, archaea, and arthropods. CONCLUSION Our findings indicate that ticks play a significant role in the transmission and evolution of poxviruses. These viruses demonstrate the capacity to modulate virulence and adaptability through horizontal gene transfer, gene recombination, and gene mutations, thereby promoting co-existence and co-evolution with their hosts. This study advances understanding of the ecological dynamics of poxvirus transmission and evolution and highlights the potential role of ticks as vectors and vessels in these processes.
Animals ; Poxviridae/physiology* ; Ticks/virology* ; Phylogeny ; Transcriptome ; Evolution, Molecular ; Poxviridae Infections/virology* ; Genome, Viral

Ticks are obligate, haematophagous arthropods that are distributed across the world, which may transmit more than 200 pathogens, including viruses, bacteria and parasites. A large number of tick species are widespread in China, and their transmitting tick-borne viral diseases pose a great threat to human health in endemic foci. This review describes the epidemiology of common, emerging and potentially pathogenic tick-borne viruses in China, and recommends the assessment of public health significance and pathogenicity of emerging tick-borne viruses using reverse microbial etiology, so as to provide insights into the management of emerging tick-borne diseases in China.
Animals ; Humans ; Tick-Borne Diseases/epidemiology* ; Ticks/microbiology* ; Viruses/genetics* ; Public Health ; China/epidemiology*

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.
Animals ; Female ; Typhus, Epidemic Louse-Borne ; Scrub Typhus/epidemiology* ; Severe Fever with Thrombocytopenia Syndrome ; Ticks ; Communicable Diseases ; Phlebovirus ; China/epidemiology* ; Tick-Borne Diseases/epidemiology*

Objective: To summarize the clinical characteristics, diagnosis and treatment of forest encephalitis, and provide basis for revising relevant diagnostic criteria. Methods: From January to December 2020, the clinical characteristics, diagnosis and treatment of forest encephalitis cases in the data of China National Knowledge Infrastructure (CNKI) and Wanfang Chinese journals from 2009 to 2020 were retrospectively analyzed. The measurement data are expressed in Mean±SD, numbers, and the counting data of gender, region and occupation are expressed in numbers and composition ratio. Descriptive analysis of relevant data is carried out. Results: There were 1 153 confirmed cases of forest encephalitis reported in domestic literature, including 910 males and 243 females. Age: 16-78 years old; Cases were mainly distributed in Jilin Province, Inner Mongolia Autonomous Region and Heilongjiang Province. The cases included forest rangers (112/518), freelancers (104/518) and loggers (88/518). The common symptoms and signs were fever 81.2% (936/1153), headache 70.3% (811/1153), meninges irritation 29.0% (334/1153), vomiting 25.3% (292/1153), nausea 21.8% (251/1153), etc. Only 48.1% (555/1153) of the patients obtained positive pathogenic test results from blood and/or cerebrospinal fluid specimens. 42.1% (485/1153) had definite diagnosis grade, 354 cases were mild, 58 cases were moderate, and 73 cases were severe. Among 730 patients with forest encephalitis who received complete treatment, 511 cases were cured, 148 cases were improved, 48 cases were not cured, and 23 cases died. Conclusion: The epidemic of forest encephalitis has strict regional, seasonal and occupational characteristics. Early diagnosis and treatment can reduce the mortality and disability rate.
Male ; Female ; Humans ; Adolescent ; Young Adult ; Adult ; Middle Aged ; Aged ; Retrospective Studies ; Encephalitis, Tick-Borne ; Encephalitis/epidemiology* ; Headache ; Fever

Pathogens like bacteria and protozoa, which affect human and animal health worldwide, can be transmitted by vectors like ticks. To investigate the epidemiology and genetic diversity of bacteria and protozoans carried by ticks in Chengmai county of Hainan province, China, 285 adult hard ticks belonging to two species [
Anaplasmataceae/isolation & purification* ; Animals ; Chaperonin 60/genetics* ; China ; Citrate (si)-Synthase/genetics* ; Coccidia/isolation & purification* ; Coxiellaceae/isolation & purification* ; Insect Vectors/microbiology* ; Islands ; Ixodidae/microbiology* ; Phylogeny ; Piroplasmia/isolation & purification* ; RNA, Ribosomal, 16S/genetics* ; RNA, Ribosomal, 18S/genetics*

Rickettsial infections (Rickettsioses) are the causes of acute fever found in Thailand. It is classified as acute febrile illnesses transmitted by bloodsucking arthropod vectors (tick, flea, and chigger). This research investigated pathogens of scrub typhus in vectors from Bangkaew District, Phatthalung Province. A total of 303 pools of vector samples were ticks (Rhipicephalus sanguineus, R. microplus, and Haemaphysalis sp.), fleas (Ctenocephalides felis orientis, C. f. felis, and C. canis), and chiggers (Leptotrombidium deliense, Aschoschoengastia indica, Blankaartia acuscutellaris and Walchia disparunguis pingue) collected from reservoir hosts (dogs and rodents). The 17 and 56 kDa gene of Rickettsia causing scrub typhus were found in 29% of ticks and 98% of flea. DNA sequence analysis reveeled the detected strains were R. asembonensis and Rickettsia sp. cf1 and 5.The chiggers, 1%, were infected with Rickettsia strain TA763, a pathogen of scrub typhus.
Animals ; Arthropod Vectors ; Cats ; Felis ; Fever ; Orientia tsutsugamushi ; Rickettsia ; Scrub Typhus ; Sequence Analysis, DNA ; Siphonaptera ; Thailand ; Ticks ; Trombiculidae

This study was done to characterize distribution of Rickettsia spp. in ticks in the northwestern and southwestern provinces in the Republic of Korea. A total of 2,814 ticks were collected between May and September 2009. After pooling, 284 tick DNA samples were screened for a gene of Rickettsia-specific 17-kDa protein using nested PCR (nPCR), and produced 88 nPCR positive samples. Of these positives, 75% contained 190-kDa outer membrane protein gene (ompA), 50% 120-kDa outer membrane protein gene (ompB), and 64.7% gene D (sca4). The nPCR products of ompA, ompB, and sca4 genes revealed close relatedness to Rickettsia japonica, R. heilongjiangensis, and R. monacensis. Most Rickettsia species were detected in Haemaphysalis longicornis. This tick was found a dominant vector of rickettsiae in the study regions in the Republic of Korea.
DNA ; Genes, vif ; Membrane Proteins ; Polymerase Chain Reaction ; Republic of Korea ; Rickettsia ; Ticks

This study aimed to investigate the tick species and give background for tick-borne investigations in Korea. Ticks were collected from the area within 2 km radius of the 4 domestic animal farms, where they were located in mountainous areas and raising animals on pasture, and from animal bodies in 2014 and 2015. In total, 7,973 nymphal and adult ticks were collected from the farms
Adult ; Agriculture ; Animals ; Animals, Domestic ; Cattle ; Ecosystem ; Goats ; Humans ; Ixodes ; Korea ; Radius ; Sus scrofa ; Ticks

OBJECTIVES: Jeju Province is well known as the region showing the highest incidence of severe fever with thrombocytopenia syndrome (SFTS) in South Korea. The aim of this study was to evaluate the epidemiological and clinical characteristics of SFTS patients in Jeju Province. METHODS: The primary data for this study were obtained from the Integrated Diseases and Health Control System of the Korea Centers for Disease Control and Prevention (KCDCIS). The selection criteria were confirmed cases of SFTS with a residence listed in Jeju Province at the time of diagnosis, reported to the KCDCIS between July 16, 2014 and November 30, 2018. RESULTS: Of 55 confirmed cases of SFTS, the case fatality rate was 10.9% (95% confidence interval [CI], 4.1 to 22.2). The most common presenting symptoms at diagnosis of severe fever, myalgia, and diarrhea had incidences of 83.6% (95% Cl, 71.2 to 92.2), 45.5% (95% Cl, 32.0 to 59.5), and 40.0% (95% CI, 27.0 to 54.1), respectively. CONCLUSIONS: Compared to SFTS patients nationwide in 2013-2015, the subjects of this study exhibited a lower case fatality rate and had a lower incidence of severe fever, myalgia, and confusion.
Bunyaviridae Infections ; Centers for Disease Control and Prevention (U.S.) ; Diagnosis ; Diarrhea ; Fever ; Humans ; Incidence ; Korea ; Mortality ; Myalgia ; Patient Selection ; Thrombocytopenia ; Tick-Borne Diseases

OBJECTIVE: Tick-borne encephalitis virus (TBEV) is an emerging pathogen in Europe and North Asia that causes tick-borne encephalitis (TBE). A simple, rapid method for detecting TBEV RNA is needed to control this disease. METHODS: A reverse-transcription recombinase-aided amplification (RT-RAA) assay was developed. This assay can be completed in one closed tube at 39 °C within 30 minutes. The sensitivity and specificity of RT-RAA were validated using non-infectious synthetic RNA representing a fragment of the NS5 region of the wild-type (WT) TBEV genome and the Senzhang strain. Additionally, 10 batches of tick samples were used to evaluate the performance of the RT-RAA assay. RESULTS: The analytical limit of detection of the assay was 20 copies per reaction of the TBEV synthetic transcript and 3 plaque-forming units (pfu) per reaction of TBEV titers. With the specific assay, no signal due to other arboviruses was observed. Of the 10 batches of tick samples obtained from the Changbai Mountains of China, three were TBEV-positive, which was consistent with the results of the quantitative real-time PCR assay. CONCLUSION A rapid, highly sensitive, specific, and easy-to-use method was developed for the detection of the TBEV Far-Eastern subtype.
Encephalitis Viruses, Tick-Borne ; genetics ; isolation & purification ; Nucleic Acid Amplification Techniques ; RNA, Viral ; analysis